HomeMy WebLinkAboutDiamond Bar General Plan 2040 Environmental Impact Report.pdfENVIRONMENTAL IMPAC T REPORT 2040
FINAL ENVIRONMENTAL IMPACT REPORT
NOVEMBER 2019
FINAL ENVIRONMENTAL IMPACT REPORT
NOVEMBER 2019
Prepared by
ENVIRONMENTAL IMPAC T REPORT 2040
Table of Contents
1 Introduction .............................................................................................................. 1-1
Purpose .................................................................................................................................................1-1
CEQA Process ....................................................................................................................................1-1
New Information in the Final EIR .....................................................................................................1-2
Organization ........................................................................................................................................1-3
2 Comments on the Draft EIR ................................................................................... 2-1
3 Responses to Comments ......................................................................................... 3-1
4 Revisions to the Draft EIR ....................................................................................... 4-1
Executive Summary.............................................................................................................................4-1
Chapter 3.1: Aesthetics .....................................................................................................................4-3
Chapter 3.2: Air Quality ....................................................................................................................4-5
Chapter 3.3: Biological Resources ...................................................................................................4-8
Chapter 3.4: Cultural, Historic, and Tribal Cultural Resources .............................................. 4-19
Chapter 3.5: Energy, Climate Change, and Greenhouse Gases............................................... 4-19
Chapter 3.6: Geology, Soils, and Seismicity................................................................................. 4-23
Chapter 3.7: Hazards, Hazardous Materials, and Wildfire ....................................................... 4-25
Chapter 3.8: Hydrology and Water Quality ............................................................................... 4-27
Chapter 3.9: Land Use and Housing ............................................................................................. 4-31
Chapter 3.10: Noise ........................................................................................................................ 4-33
Chapter 3.11: Public Facilities and Recreation ............................................................................ 4-34
Chapter 3.12: Transportation ........................................................................................................ 4-40
Chapter 3.13: Utilities and Service Systems ................................................................................ 4-44
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1 Introduction
This Final Environmental Impact Report (Final EIR) has been prepared by the City of Diamond
Bar in accordance with the California Environmental Quality Act (CEQA) (Public Resources Code
Section 21000 et seq.). The Draft EIR analyzes potential environmental impacts of the adoption and
implementation of the proposed Diamond Bar General Plan 2040 and Climate Action Plan,
Project This Final EIR provides responses to comments on the Draft
EIR as well as corrections and clarifications to the Draft EIR. The City of Diamond Bar is the lead
agency responsible for ensuring that the proposed General Plan complies with CEQA.
responsibility for carrying out or approving a project which may have a significant effect upon the
Purpose
This document, combined with the Draft EIR, published September 16, 2019, constitutes the Final
EIR on the Proposed Project as described in Chapter 2: Project Description of the Draft EIR. The
primary purpose of the Final EIR is to revise and refine the environmental analysis in the Draft EIR
in response to comments received during the public review period. The public review period for
the Draft EIR (State Clearinghouse No. 2018051066) lasted for 45 days, from Monday, September
16, 2019 to Thursday, October 31, 2019.
This Final EIR amends and incorporates by reference the Draft EIR. This document includes
comments and responses to comments on the Draft EIR, and corrections and clarifications to the
Draft EIR. The EIR is intended to disclose to City of Diamond Bar decision makers, responsible
agencies, organizations, and the general public the potential impacts of implementing the Proposed
Project using a program level of analysis. The Draft EIR, Public Review Draft Diamond Bar General
Plan 2040, and Public Review Draft Climate Action Plan are available for review at the City of
Diamond Bar General Plan website (http://www.diamondbargp.com/).
CEQA Process
Before the City may approve the various discretionary actions needed to implement the Proposed
Project, it must independently review and consider the informatio n contained in the Final EIR,
certifying that the Final EIR adequately discloses the environmental effects of the Proposed Project,
that the Final EIR has been completed in conformance with CEQA, and that the decision -making
body of the Lead Agency independently reviewed and considered the information contained in the
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 1: Introduction
1-2
Final EIR. Certification of the Final EIR would indicate the C
adequately evaluates the environmental impacts that could be associated with the Proposed Project.
For impacts identified in the EIR that cannot be reduced to a level that is less than significant, the
City must make findings and prepare a Statement of Overriding Considerations for approval of the
Proposed Project if specific social, economic, or other factors justify the Proposed
unavoidable adverse environmental effects. If the City decides to approve the Proposed Project for
which the Final EIR has been prepared, it will issue a Notice of Determ ination.
The City of Diamond Bar has prepared this document pursuant to CEQA Guidelines Section 15132 ,
which specifies that the Final EIR shall consist of:
• The Draft EIR or a revision of the Draft;
• A list of persons, organizations, and public agencies comm enting on the Draft EIR;
• Comments and recommendations received on the Draft EIR;
• The response of the Lead Agency to significant environmental points raised in the review
process; and
• Any other information added by the Lead Agency.
This Final EIR incorporates comments from public agencies and the general public. It also contains
The Final EIR can also be accessed through the
City of Diamond Bar General Plan website.
New Information in the Final EIR
If significant new information is added to an EIR after notice of public review has been given, but
before final certification of the EIR, the Lead Agency must issue a new notice and recirculate the
EIR for further comments and consultation. Significant new i nformation is that which discloses
that:
• A new significant environmental impact would result from the project or from a new
mitigation measure proposed to be implemented;
• A substantial increase in the severity of an environmental impact would result unles s
mitigation measures are adopted that reduce the impact to a level of insignificance;
• A feasible project alternative or mitigation measure considerably different from others
previously analyzed would clearly lessen the significant environmental impacts o f the
• The Draft EIR was so fundamentally and basically inadequate and conclusory in nature
that meaningful public review and comment were precluded.
Corrections or clarifications to the Draft EIR identified in Chapter 3 of this document do not
constitute significant new information pursuant to Section 15088.5 of the CEQA Guidelines; this
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 1: Introduction
1-3
new information merely clarifies and makes insignificant changes to an adequate EIR. Information
presented in the Draft EIR and this document support this determination.
Organization
This document contains the following components:
• Chapter 1
• Chapter 2 lists all of the agencies, organizations and individuals that submitted written
comments on the Draft EIR; reproduces all comments; and provides a unique number for
each comment in the page margin.
• Chapter 3 provides numbered responses to comments on the Draft EIR keyed to the
comment letters included in Chapter 2 . Revisions are acknowledged where necessary to
clarify or amplify, and are included in Chapter 4.
• Chapter 4 provides an errata sheet with revisions to the Draft EIR where necessary to
clarify or amplify. Revisions are organized by Draft EIR section and by page nu mber.
Where such revisions are warranted in response to comments on the Draft EIR, deletions
are shown in strikethrough and additions are shown underlined in the matrix of comments
and responses. Map revisions required in response to comments are included at the end of
this chapter.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 1: Introduction
1-4
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2 Comments on the Draft EIR
This chapter contains copies of the comment letters received on the Draft EIR. A total of 1 9
comment letters and emails were received during the 45-day comment period. This chapter
includes a letter from th
Clearinghouse review requirements pursuant to CEQA and stating which comments were
submitted by State agencies. Comments received are listed in Table 2 -1.
Each letter is identified by a d Letters sent by the same commenter are
-Specific comments
within each letter are identified by a designator in the page margin that reflects the se quence of the
-
Comments are organized by public agency comments and responses (Section A) and individual
comments and responses (Section B). Within each category, comments are listed in chronological
order according to the date on the letter. Comment letters submitted on the same date are organized
by topic area, such as biological resources, where feasible.
Table 2-1: Comments Received on the Draft EIR
Letter # Date Commenter Agency/Organization
Section A: Agencies (Federal, State, Regional, Local)
A1 October 17, 2019 Michael Y. Takeshita, Acting
Chief, Forestry Division
Prevention Services Bureau
County of Los Angeles Fire
Department
A2 October 30, 2019 Alina Bokde, Deputy Director County of Los Angeles
Department of Parks and
Recreation
A3 October 30, 2019 Erinn Wilson, Environmental
Program Manager I
California Department of Fish
and Wildlife
A4 October 31, 2019 Miya Edmonson, IGR/CEQA
Branch Chief
California Department of
Transportation
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 2: Comments on the Draft EIR
2-2
Table 2-1: Comments Received on the Draft EIR
Letter # Date Commenter Agency/Organization
A5 October 31, 2019 Shine Ling, Transit Oriented
Communities Manager
Los Angeles County
Metropolitan Transportation
Authority (Metro)
A6 October 31, 2019 Robert C. Ferrante, Chief
Engineer and General Manager
Sanitation Districts of Los
Angeles County
A7 October 31, 2019 Scott Morgan, Director
Planning and Research, State
Clearinghouse and Planning Unit
Section B: Individuals
B1-A October 8, 2019 Douglas Barcon Individual
B1-B October 9, 2019 Douglas Barcon Individual
B1-C October 29, 2019 Douglas Barcon Individual
B1-D October 31, 2019 Douglas Barcon Individual
B2 October 29, 2019 Claire Schlotterbeck, Executive
Director
Hills for Everyone
B3 October 31, 2019 Robert A. Hamilton Hamilton Biological, Inc.
B4-A October 31, 2019 Lee Paulson, President Responsible Land Use
B4-B October 31, 2019 Lee Paulson, President Responsible Land Use
B5 October 31, 2019 Janet Cobb, CWF Executive
Director and Angela Moskow,
CO Manager
California Wildlife Foundation
and California Oaks Coalition
B6 October 31, 2019 C. Robin Smith, Chair Diamond Bar Pomona Valley
Sierra Club Task Force, Angeles
Chapter
B7 October 31, 2019 Diego Tamayo Individual
B8 October 31, 2019 Chia Teng , President Diamond Bar Preservation
Alliance
B9 October 31, 2019 Gary Busteed Individual
COUNTYOFLOSANGELESDEPARTMENTOFPARKSANDRECREATION“ParksMakeLifeBetter!”JohnWicker,DirectorNormaE.Garcia,ChiefDeputyDirectorOctober30,2019Ms.GraceS.LeeSeniorPlannerCityofDiamondBar,PlanningDivision21810CopleyDriveDiamondBar,CA91765DearMs.Lee:NOTICEOFAVAILABILITYOFDRAFTENVIRONMENTALIMPACTREPORTFORTHEDIAMONDBARGENERALPLANANDCLIMATEACTIONPLAN2040IamwritingwithregardstotheDraftEnvironmentalImpactReport(DEIR)fortheDiamondBarGeneralPlanandClimateActionPlan2040.LocatedwithinthePlanningAreaaretwoLosAngelesCountyDepartmentofParksandRecreation(DPR)facilities:DiamondBarGolfCourseandtheproposedSchabarumExtensionTrail.PleasefindbelowDPR’scommentsandquestions:DiamondBarGolfCourseDiamondBarGolfCourse(DBGC)wasestablishedasapublicgolfcoursein1964andwillcontinuetoserveassuchintheforeseeablefuture.ThegolfcourseisprotectedpublicparklandunderthePublicParkPreservationActof1971.ThedraftGeneralPlanincludesa“CommunityCore”focusareathatoverlaysDBGC(page2-8).The“CommunityCore”focusareaproposesamixofusesemphasizingdestinationandspecialtyretail,dining,andentertainmentonthesouthernportionoftheDBGCsite.ThisproposaldoesnotseemtotakeintoconsiderationtheParkPreservationActwhichcontainsspecificrequirementsthatmustbemetinordertoconvertpublicparklandintonon-parkuse(s).Also,theCityofDiamondBardoesnothavejurisdictionoverthisCounty-ownedgolfcourse.AnyproposednewusesontheDBGCsiteshouldbediscussedandcoordinatedwiththeCounty.TheLosAngelesCountyBoardofSupervisorshasthesolediscretiontoapprovedevelopmentonCounty-ownedproperties.Assuch,anyproposednewuse(s)ontheDBGCwouldrequirereviewandapprovalbytheBoard.PlanningandDevelopmentAgency•1000S.FremontAvenue,Unit#40,Alhambra,CA91803•(626)588-5322
Ms.GraceS.LeeOctober31,2019Page2SchabarumExtensionTrail(proposed)TheproposedSchabarumExtensionTrailconnectstheDPR-operatedRowlandHeightsLoopTrailintheunincorporatedcommunityofRowlandHeightstoSanBernardinoCountythroughpreservedopenspace.Thisten-milesegmentofproposedmulti-usetrail(hiking,biking,andhorsebackriding)utilizesportionsofunpavedSouthernCaliforniaEdisonright-of-wayandprovidesintermittentaccesstocommunitieswithintheCityofDiamondBarviarecordedtraileasements.PleasefindbelowsomequestionsandeditsregardingthediscussionoftrailsintheDEIR.Page3.11-12•ArethereanytrailsplannedontheTresHermanosRanchproperty?Page3.11-13•AreequestriansaccommodatedonCitytrails?IftheproposedSchabarumExtensionTrailweredeveloped,itwouldbecomeamulti-usetrailthatwouldservehikers,mountainbikers,andequestrians.Table3.11-6:ExistingandProposedTrailNetwork(2019)•WhichagencyhasproposedtheTonnerCanyonTrail?•PleasecorrectthenameoftheCountytrail.“SchabarumTrail(SkylineExtension)”shouldbecorrectedas“ScharabrumExtensionTrail”.TheSchabarumExtensionandTonnerCanyonTrailsare“ProposedTrails,”not“ExistingTrails.”Page3.11-14•PleasenotethattheSchabarum-SkylineTrailisoperatedbytheCountyofLosAngelesDepartmentofParksandRecreationandis29.7mileslong.•Pleaserevisethesentenceasfollows:“Thetrailallowsrccrcationaluscrsandcommutershikers,mountainbikers,andequestrianstoconnecttoavarietyofothertrailsinthearea”•Pleaseincludeanoteonthispagethatthedevelopmentofstagingareasandtrallheadswillbeconsideredatstrategiclocationstoaccommodatemulti-usetrailusers.
Ms.GraceS.LeeOctober31,2019Page3NotificationPleasenotethatDPRwasnotformallynotifiedoftheGeneralPlanupdateeventhoughthe“CommunityCore”overlaywasproposedontheDBGCsite.WeonlyreceivedtheNoticeofAvailabilityaftersigningupfore-mailnotificationontheproject’swebsiteseveralmonthsago.Thankyouforyourconsiderationofourcomments.Ifyouhaveanyquestionsorwishtodiscussfurther,pleasecontactClementLau,DepartmentalFacilitiesPlanner,ofmystaffat(626)588-5301orbyemailatclau@parks.lacounty.gov.Sicerely,AlmaBokdeDeputyDirectorAB:cL:JIc:ZL:nrc:CountyCounsel(C.Yourn)ParksandRecreation(J.Badel,W.Leary,C.Lau,L.Barocas,M.O’Connor,Z.Likins,J.Chien)
Page 1 of 4
October 31, 2019
Grace S. Lee, Senior Planner
City of Diamond Bar, Planning Division
21810 Copley Drive
Diamond Bar, CA 91765
Sent by Email:glee@diamondbarca.gov
RE: Diamond Bar General Plan Update and Climate Action Plan (CAP) – Draft Environmental Impact
Report (DEIR)
Dear Ms. Lee:
Thank you for coordinating with the Los Angeles County Metropolitan Transportation Authority (Metro)
regarding the proposed General Plan Update and CAP (Plan), located in the City of Diamond Bar (City).
Metro is committed to working with local municipalities, developers, and other stakeholders across Los
Angeles County on transit-supportive developments to grow ridership, reduce driving, and promote
walkable neighborhoods. Transit Oriented Communities (TOCs) are places (such as corridors or
neighborhoods) that, by their design, allow people to drive less and access transit more. TOCs maximize
equitable access to a multi-modal transit network as a key organizing principle of land use planning and
holistic community development.
Within the Plan area, Metro funds Metrolink commuter rail service operated by the Southern California
Regional Rail Authority (SCRRA). The purpose of this letter is to briefly describe the proposed Plan
(based on the DEIR’s project description), outline recommendations from Metro concerning issues that
are germane to our agency’s statutory responsibility in relation to Metrolink facilities and services that
may be affected by the proposed Plan, and help identify opportunities in the Plan to support transit
ridership.
Plan Description
The Plan includes the Diamond Bar Plan 2040, which is a long-term document expressing the goals,
objectives, and policies necessary to guide the community toward achieving its vision over a 20-year
period. The Plan also includes a CAP, which is a comprehensive plan for addressing a community’s
greenhouse gas (GHG) emissions.
Diamond Bar General Plan Update and CAP
DEIR – Metro Comments
October 31, 2019
Page 2 of 4
Transit Service Considerations
1.Coordination Resource: To improve coordination between the City, adjacent development and
Metro, Metro would like to provide the City with a user-friendly resource, the Metro Adjacent
Development Handbook (attached), which provides an overview of common concerns for
development adjacent to Metrolink ROW. This document and additional resources are available
at www.metro.net/devreview/. Metro encourages the City to provide this document as a
resource to all development projects adjacent to Metro ROW.
2.Rail Operations, Noise & Vibration: Metrolink operates within the Plan area, serving Industry
Station. Metrolink operates in and out of revenue service, 24 hours a day, seven days a week.
Considering the proximity of the Plan area to Metrolink, it is expected that rail operations may
produce noise and vibration.
3.Plan Policies to address Transit: To further address the land use and noise compatibility of future
development in the vicinity of Industry Station, Metro recommends that the Plan include
policies to require future development projects in the Station’s vicinity to record a notice to
property owners and tenants to advise of the presence of railway noise and vibration sources.
Any noise mitigation required for future development projects must be borne by the project
applicants and not Metrolink.
4.Climate Action Planning: Metro encourages the City to review the Plan’s consistency with
Metro’s 2019 Climate Action and Adaptation Plan (CAAP) and the Southern California
Association of Governments’ 2020-2045 Regional Transportation Plan/Sustainable Communities
Strategy to ensure the Plan will not conflict with those plans. Metro’s 2019 CAP is available at
http://media.metro.net/projects_studies/sustainability/images/Climate_Action_Plan.pdf.
Transit Orientation Considerations
Considering the Plan area’s proximity to the Industry Station, Metro would like to identify the potential
synergies associated with transit-oriented development:
1.Transit-Supportive Planning: To achieve Metro’s program objectives, Metro strongly
recommends that the City review the Transit-Supportive Planning Toolkit which identifies 10
elements of transit-supportive places and applied collectively, has been shown to reduce vehicle
miles traveled by establishing community-scaled density, diverse land use mix, combination of
affordable housing, and infrastructure projects for pedestrians, bicyclists, and people of all ages
and abilities. This resource is available at https://www.metro.net/projects/tod-toolkit.
2.Land Use: Metro supports development of commercial and residential properties near transit
stations and understands that increasing development near stations represents a mutually
beneficial opportunity to increase ridership and enhance transportation options for the users of
Diamond Bar General Plan Update and CAP
DEIR – Metro Comments
October 31, 2019
Page 3 of 4
developments. Metro encourages the City to be mindful of the Plan’s proximity to the Industry
Station, including orienting pedestrian pathways towards the station.
3.Transit Connections:
a.Transfer Activity: Given the Plan’s proximity to the Industry Station, proposed project
design should consider and accommodate transfer activity between bus and rail lines that
will occur along the sidewalks and public spaces. Metro has completed the Metro Transfers
Design Guide, a best practices document on transit improvements. This can be accessed
online at https://www.metro.net/projects/systemwidedesign.
b.Access: The Plan should address first-last mile connections to transit, encouraging
development that is transit-accessible with bicycle and pedestrian-oriented street design
that connects transportation with housing and employment centers. The City is also
encouraged to support these connections with wayfinding signage inclusive of all modes of
transportation. For reference, please review the First Last Mile Strategic Plan, authored by
Metro and the Southern California Association of Governments (SCAG), available on-line at:
http://media.metro.net/docs/sustainability_path_design_guidelines.pdf
4.Active Transportation: Metro strongly encourages the City to install project features that help
facilitate safe and convenient connections for pedestrians, people riding bicycles, and transit
users to/from the Industry Station and nearby destinations. The City should consider requiring
the installation of such features as part of the conditions of approval for proposed projects.
These features can include the following:
a.Walkability: The installation of wide sidewalks, pedestrian lighting, a continuous
canopy of shade trees, enhanced crosswalks with ADA-compliant curb ramps, and
other amenities along all public street frontages of the development site to improve
pedestrian safety and comfort to access the nearby rail station.
b.Bicycle Use: The provision of adequate short-term bicycle parking, such as ground
level bicycle racks, and secure, access-controlled, enclosed long-term bicycle parking
for residents, employees and guests. Bicycle parking facilities should be designed
with best practices in mind, including highly visible siting, effective surveillance, easy
to locate, and equipment installed with preferred spacing dimensions, so they can
be safely and conveniently accessed.
5.Parking: Metro encourages the incorporation of transit-oriented, pedestrian-oriented parking
provision strategies such as the reduction or removal of minimum parking requirements for
specific areas and the exploration of shared parking opportunities. These strategies could be
pursued to reduce automobile-orientation in design and travel demand.
Diamond Bar General Plan Update and CAP
DEIR – Metro Comments
October 31, 2019
Page 4 of 4
Metro looks forward to continuing to collaborate with the City to effectuate policies and
implementation activities that promote transit oriented communities. If you have any questions
regarding this response, please contact me by phone at 213-922-2671, by email at
devreview@metro.net, or by mail at the following address:
Metro Development Review
One Gateway Plaza MS 99-22-1
Los Angeles, CA 90012-2952
Sincerely,
Shine Ling, AICP
Manager, Transit Oriented Communities
Attachments and links:
Adjacent Development Handbook:https://www.metro.net/projects/devreview/
Los Angeles County
Metropolitan Transport ation Authority me tro adjacent development handbook
a guide for cities and developers
MAY 2018
i Metro Adjacent Development Handbook
Introduction 2
Who is Metro? 2
Why is Metro Interested in Adjacent Development? 5
Metro Adjacent Development Handbook 6
What are the Goals of the Handbook? 6
Who Should Use the Handbook? 6
How Should the Handbook be Used? 7
Types of Metro ROW and Transit Assets 8
Metro Adjacent Development Review 9
Metro Review Phases 9
Metro Coordination 11
Best Practices for Municipality Coordination 11
Best Practices for Developer Coordination 11
1: Site Planning & Design 14
1.1 Supporting Transit Oriented Communities 15
1.2 Enhancing Access to Transit 16
1.3 Building Setback 17
1.4 Shared Barrier Construction & Maintenance 18
1.5 Project Orientation & Noise Mitigation 19
1.6 Sightlines at Crossings 20
1.7 Transit Envelope Clearance 21
1.8 Bus Stops & Zones Design 22
1.9 Driveway/Access Management 23
Table of Contents
Metro Adjacent Development Handbook ii
2: Engineering 26
2.1 Excavation Support System Design 27
2.2 Proximity to Stations & Tunnels 28
2.3 Protection from Explosion/Blast 29
3: Construction Safety & Monitoring 32
3.1 Pre-Construction Coordination 33
3.2 Track Access and Safety 34
3.3 Construction Hours 35
3.4 Excavation/Drilling Monitoring 36
3.5 Crane Operations 37
3.6 Construction Barriers & Overhead Protection 38
3.7 Pedestrian & Emergency Access 39
3.8 Impacts to Bus Routes & Stops 40
3.9 Utility Coordination 41
3.10 Air Quality & Ventilation Protection 42
Resources 43
Metro Contact Information 43
Metro Adjacent Development Review Tools 43
Metro Right-of-Way GIS Data 43
Metro Design Criteria & Standards 44
Metrolink Standards & Procedures 44
Metro Policies & Plans 44
Metro Programs & Toolkits 45
Useful Policies & Resources 45
Glossary 47
Table of Contents
1 Metro Adjacent Development Handbook
Metro Adjacent Development Handbook 2
The Metro Adjacent Development Handbook provides guidance to local jurisdictions and developers constructing on,
adjacent, over, or under Metro right of way, non-revenue property, or transit facilities to support transit-oriented
communities, reduce potential conflicts, and facilitate clearance for building permits. The Handbook should be used
for guidance purposes only. The Metro Adjacent Construction Design Manual and Metro Rail Design Criteria are
documents that shall be strictly adhered to for obtaining approval for any construction adjacent to Metro facilities.
Who is Metro?
The Los Angeles County Metropolitan Transportation Authority (Metro) plans, funds, builds, and operates rail and bus
service throughout Los Angeles County. Metro moves close to 1.3 million riders on buses and trains daily, traversing
many jurisdictions in Los Angeles County. With funding from the passage of Measure R (2008) and Measure M
(2016), the Metro system will expand significantly, adding over 100 miles of new transit corridors and up to 60 new
stations. New and expanded transit lines will improve mobility across Los Angeles County, connecting riders to more
destinations and expanding opportunities for adjacent construction and Transit Oriented Communities (TOCs).
Metro’s bus and rail service spans over 1,433 square miles and includes the following transit service:
Metro Rail connects close to 100 stations along 98.5 miles of track and operates underground in
tunnels, at grade within roadways and dedicated rights-of-way (ROW), and above grade on aerial
guideways. The Metro Rail fleet includes heavy rail and light rail vehicles. Heavy rail vehicles are
powered by a third rail through a conductor along the tracks and light rail vehicles are powered
by an overhead catenary system (OCS). To operate rail service, Metro owns traction power
substations, maintenance yards and shops, and supporting infrastructure.
Metro Bus-Rapid-Transit (BRT) operates accelerated bus transit, which serves as a hybrid
between rail and traditional bus service. BRT operates along a dedicated ROW, separated from
vehicular traffic to provide rapid service. Metro BRT may run within the center of a freeway or
may be separated from traffic in its own corridor. BRT station footprints vary from integrated,
more spacious stations to compact boarding areas along streets.
Metro Bus serves 15,967 bus stops, operates 170 routes and covers 1,433 square miles with a
fleet of 2,228 buses. Metro “Local” and “Rapid” bus service runs within the street, typically
alongside vehicular traffic, though occasionally in “bus-only” lanes. Metro bus stops are typically
located on sidewalks within the public right-of-way, which is owned and maintained by local
jurisdictions.
Metrolink/Regional Rail: Metro owns much of the ROW within Los Angeles County on which the
Southern California Regional Rail Authority (SCRRA) operates Metrolink service. Metrolink is a
commuter rail system with seven lines that span 388 miles throughout Los Angeles, Orange,
Riverside, San Bernardino, Ventura, and North San Diego counties. As a SCRRA member agency
and property owner, Metro reviews development activity adjacent to Metrolink ROW.
Introduction
3 Metro Adjacent Development Handbook
Metro and Regional Rail Map
Metro is currently undertaking the largest rail infrastructure expansion effort in the United States. A growing fixed
guideway system presents new adjacency challenges, but also new opportunities to catalyze land use investment and
shape livable communities along routes and around stations.
Introduction
Metro Adjacent Development Handbook 4
Metro Bus and Rail System Map (Excerpt)
As a street-running transit service, Metro’s “Rapid” and “Local” buses share the public ROW with other vehicles,
cyclists, and pedestrians, and travel through the diverse landscapes of Los Angeles County’s 88 cities and
unincorporated areas.
5 Metro Adjacent Development Handbook
Why is Metro Interested in Adjacent Development?
Metro Supports Transit Oriented Communities
Metro is redefining the role of the transit agency by expanding mobility options, promoting sustainable urban design,
and helping transform communities throughout Los Angeles County. Leading in this effort is Metro’s vision to create
TOCs, a mobility and development approach that is community-focused and context-responsive at its core. The TOC
approach goes beyond the traditional transit oriented development (TOD) model to focus on shaping vibrant places
that are compact, walkable, and bikeable community spaces, and acknowledge mobility as an integral part of the urban
fabric.
Adjacent Development Leads to Transit Oriented Communities
Metro supports private development adjacent to transit as this presents a mutually beneficial opportunity to enrich the
built environment and expand mobility options for users of developments. By connecting communities, destinations,
and amenities through improved access to public transit, adjacent developments have the potential to reduce car
dependency and greenhouse gas emissions; promote walkable and bikeable communities that accommodate more
healthy and active lifestyles; improve access to jobs and economic opportunities; and create more opportunities for
mobility – highly desirable features in an increasingly urbanized environment.
Metro is committed to working with stakeholders across the County to support the development of a sustainable,
welcoming, and well-designed environment around its transit services and facilities. Acknowledging an unprecedented
opportunity to influence how the built environment throughout Los Angeles County develops along and around transit
and its facilities, Metro has created this Handbook – a resource for municipalities, developers, architects, and
engineers to use in their land use planning, design, and development efforts. This Handbook presents a crucial first
step in active collaboration with local stakeholders; finding partnerships that leverage Metro initiatives and support
TOCs across Los Angeles County; and ensuring compatibility with transit infrastructure to minimize operational,
safety, and maintenance issues.
Introduction
Metro Adjacent Development Handbook 6
What are the Goals of the Handbook?
Metro is committed to partnering with local jurisdictions and providing information to developers early in project
planning to identify potential synergies associated with building next to transit and reduce potential conflicts with
transit infrastructure and services. Specifically, the Handbook is intended to guide the design, engineering,
construction, and maintenance of structures within 100 feet of Metro ROW, including underground easements, on
which Metro operates or plans to operate service, as well as in close proximity to or on Metro-owned non-revenue
property and transit facilities.
Metro is interested in reviewing projects within 100 feet of its ROW – measured from the edge of the ROW outward –
both to maximize integration opportunities with adjacent development and to ensure the structural safety of existing
or planned transit infrastructure. As such, the Handbook seeks to:
• Improve communication, coordination, and understanding between developers, municipalities, and Metro.
• Streamline the development review process by coordinating a seamless, comprehensive agency review of all
proposed developments near Metro facilities and properties.
• Highlight Metro operational needs and requirements to ensure safe, continuous service.
• Identify common concerns associated with developments adjacent to Metro ROW.
• Prevent potential impacts to Metro transit service or infrastructur e.
• Maintain access to Metro facilities for patrons and operational staff.
• Avoid preventable conflicts resulting in increased development costs, construction delays, and safety impacts.
• Make project review transparent, clear, and more efficient.
• Assist in the creation of overall marketable and desirable developments.
Who Should Use the Handbook?
The Handbook is intended to be used by:
• Local jurisdictions who review, entitle, and permit development projects and/or develop policies related to
land use, development standards, and mobility
• Developers, Project sponsors, architects, and engineers
• Entitlement consultants
• Property owners
• Builders/contractors
• Real estate agents
• Utility owners
• Environmental consultants
Metro Adjacent Development Handbook
7 Metro Adjacent Development Handbook
How Should the Handbook be Used?
The Handbook complements requirements housed in the Metro Adjacent Construction Design Manual, which
accompanies the Metro Rail Design Criteria (MRDC) and other governing documents that make up the Metro Design
Criteria and Standards. This Handbook provides an overview and guide related to opportunities, common concerns,
and issues for adjacent development and is organized into three categories to respond to different stages of the
development process:
Each page of the Handbook focuses on a specific issue and provides best practices to avoid potential conflicts and/or
create compatibility with the Metro transit system. Links to additional resources listed at the bottom of each page may
be found under Resources at the end of the Handbook. Definitions for words listed in italics may also be found at the
end of this Handbook in the Glossary.
Metro will continue to revise the Handbook, as needed, to capture input from all parties and reflect evolving Best
Practices in safety, operations, and transit-supportive development.
Site Planning &
Design 1 Engineering 2 Construction Safety
& Monitoring 3
Metro Adjacent Development Handbook
Metro Adjacent Development Handbook 8
Types of Metro ROW & Transit Assets
Conditions Description Common Concerns for Metro with
Adjacent Development
UNDERGROUND
ROW
Transit operates below ground in
tunnels.
• Excavation support/tiebacks
• Underground utilities
• Shoring and structures
• Ventilation shafts and street/sidewalk surface
penetrations
• Appendages (emergency exits, vents, etc.)
• Surcharge loading of adjacent construction
• Explosions
• Noise and vibration/ground movement
ELEVATED ROW
Transit operates on elevated
structures, typically supported by
columns.
• Upper level setbacks
• Excavation support/tiebacks
• Clearance from the OCS
• Crane swings & overhead protection
• Column foundations
OFF-STREET ROW
Transit operates in dedicated ROW
at street level, typically separated
from private property or roadway by
a fence or wall.
• Building setbacks from ROW
• Travel sight distance/cone of visibility
• Clearance from OCS
• Crane swings & overhead protection
• Storm water drainage for low impact development
• Noise/vibration
• Trackbed stability
ON-STREET ROW
Transit operates within roadway at
street level and is separated by
fencing or a mountable curb.
• Setbacks from ROW
• Travel sight distance/cone of visibility impeded by
structures near ROW
• Clearance from OCS
• Crane swings & overhead protection
• Driveways near ROW crossings
• Noise/vibration
• Trackbed stability
ON-STREET BUSES
Metro buses operate on city
streets. Bus stops are located on
public sidewalks.
• Lane closures and re-routing
• Bus stop access and temporary relocation
NON-REVENUE/
OPERATIONAL
ASSETS
Metro owns and maintains non-
operational ROW and property
used to support the existing and
planned transit system (e.g. bus
and rail maintenance facilities,
transit plazas, traction power
substations, park-and-ride lots).
• Adjacent structure setbacks
• Adjacent excavation support/tiebacks
• Ground movement
• Underground utilities
• Drainage
• Metro access
9 Metro Adjacent Development Handbook
Metro Review Phases
To facilitate early and continuous coordination with development teams and municipalities, and to maximize
opportunities for project-transit synergy, Metro employs a four-phase development review process for projects within
100 feet of its ROW and properties:
PRELIMINARY CONSULTATION
Project sponsor submits Metro In-Take Form and conceptual plans. Metro reviews and
responds with preliminary considerations.
1. Project information is routed to impacted Metro departments for review and
comment.
2. Metro coordinates a meeting at the request of the project sponsor or if Metro
determines it necessary following preliminary review.
3. Metro submits comment letter with preliminary considerations for municipality
and/or project sponsor. Metro recorded drawings and standards are provided as
necessary. 2 Weeks
ENTITLEMENT
Metro receives CEQA notice from local municipality and responds with comments and
considerations.
1. If project has not previously been reviewed, Metro routes project information to
stakeholder departments for review and comment. If Project has been reviewed,
Metro transmits the correspondence to departments to determine if additional
comments are warranted. Municipality and project sponsor are contacted if
additional information is required.
2. Metro coordinates design review meetings at the request of the project sponsor
or if Metro determines them necessary following drawings review.
3. Metro prepares comment letter in response to CEQA notice and submits to
municipality. Metro Engineering coordinates with project sponsor as necessary to
approve project drawings. 2-4 Weeks
Metro Adjacent Development Handbook
Metro Adjacent Development Handbook 10
ENGINEERING & REFINEMENT
Dependent on the nature of the adjacent development, project sponsor submits
architectural plans and engineering calculations for Metro review and approval.
1. Metro Engineering reviews project plans, calculations, and other materials.
Review fees are paid as required.
2. Metro Engineering provides additional comments for further consideration or
approves project drawings.
3. If required, Metro and project sponsor host additional meetings and maintain
on-going coordination to ensure project design does not adversely impact Metro
operations and facilities. 2-4 Weeks
CONSTRUCTION SAFETY & MONITORING
Dependent on the nature of the adjacent development, Metro coordinates with project
sponsor to facilitate and monitor construction near transit services and structures.
1. As requested by Metro, project sponsor submits a Construction Work Plan for
review and approval.
2. Project sponsor coordinates with Metro to temporarily relocate bus stops, reroute
bus service, allocate track, and/or complete safety procedures in preparation for
construction.
3. Metro representative monitors construction and maintains communication with
project sponsor to administer the highest degree of construction safety
provisions near Metro facilities. Varies
11 Metro Adjacent Development Handbook
Best Practices for Municipality Coordination
Metro suggests that local jurisdiction s take the following steps to streamline the coordination process:
1. Update GIS instruments with Metro ROW: Integrate Metro ROW files into City GIS and/or Google Earth Files for
all planning and development review staff.
2. Flag Parcels: Create an overlay zone through Specific Plans and/or Zoning Ordinance that “tags” parcels within
100’ from Metro ROW to require coordination with Metro early during the development process [e.g. City of Los
Angeles Zone Information and Map Access System (ZIMAS)].
3. Provide Resources: Direct all property owners and developers interested in parcels within 100’ from Metro ROW
to Metro resources (e.g. website, Handbook, In-Take Form, etc.).
Best Practices for Developer Coordination
Metro suggests that developers of projects adjacent to Metro ROW take the following steps to facilitate Metro project
review and approval:
1. Review Metro resources and policies: The Metro Adjacent Development Review webpage and Handbook provide
important resources for those interested in constructing on, adjacent, over, or under Metro right of way, non -
revenue property, or transit facilities. Developers should familiarize themselves with these resources and keep in
mind common adjacency concerns when planning a project.
2. Contact Metro early during design process: Metro welcomes the opportunity to provide feedback early in project
design, allowing for detection and resolution of important adjacency issues, identification of urban design and
system integration opportunities, and facilitation of permit approval.
3. Maintain communication: Frequent communication with stakeholder Metro departments during project design
and construction will reinforce relationships and allow for timely project completion.
Metro Coordination
Metro Adjacent Development Handbook 12
13 Metro Adjacent Development Handbook
Metro Adjacent Development Handbook 14
Site Planning
& Design 1
15 Metro Adjacent Development Handbook
1.1 Supporting Transit Oriented
Communities
Adjacent development plays a crucial role in shaping TOCs along and
around Metro transit services and facilities. TOCs require an
intentional orchestration of physical, aesthetic, and operational
elements, and close coordination by all stakeholders , including Metro,
developers, and municipalities.
Recommendation: Conceive projects as an integrated system that
acknowledges context, builds on user needs and desires, and
implements elements of placemaking. Metro is interested in
collaborating with projects and teams that, in part or wholly:
• Integrate a mix of uses to create lively, vibrant places that
are active day and night.
• Include a combination of buildings and public spaces to
define unique and memorable places.
• Explore a range of densities and massing to optimize
building functionality while acknowledging context-sensitive
scale and architectural form.
• Activate ground floor with retail and outdoor
seating/activities to bring life to the public environment.
• Prioritize pedestrian scaled elements to create spaces that
are comfortable, safe, and enjoyable.
• Provide seamless transitions between uses to encourage
non-motorized mobility, improve public fitness and health,
and reduce road congestion.
• Reduce and hide parking to focus on pedestrian activity.
• Prevent crime through environmental design.
• Leverage regulatory TOD incentives to design a more
compelling project that capitalizes on transit adjacency and
economy of scales.
• Utilize Metro policies and programs supporting a healthy,
sustainable, and welcoming environment around transit
service and facilities.
Links to Metro policies and programs may be found in the
Resources Section of this Handbook.
The Wilshire/Vermont Metro Joint Development
project leveraged existing transit infrastructure
to catalyze a dynamic and accessible urban
environment. The project accommodates portal
access into the Metro Rail system and on-street
bus facilities.
Site Planning & Design 1
Metro Adjacent Development Handbook 16
1.2 Enhancing Access to Transit
Metro seeks to create a comprehensive, integrated transportation
network and supports infrastructure and design that allows safe and
convenient access to its multimodal services. Projects in close
proximity to Metro’s services and facilities present an opportunity to
enhance the public realm and connections to/from these services for
transit patrons as well as users of the developments.
Recommendation: Design projects with transit access in mind.
Project teams should capitalize on the opportunity to improve the
built environment and enhance the public realm for pedestrians,
bicyclists, persons with disabilities, seniors, children, and users of
green modes. Metro recommends that projects:
• Orient major entrances to transit service, making access
and travel intuitive and convenient.
• Plan for a continuous canopy of shade trees along all public
right-of-way frontages to improve pedestrian comfort to
transit facilities.
• Add pedestrian lighting along paths to transit facilities and
nearby destinations.
• Integrate wayfinding and signage into project design.
• Enhance nearby crosswalks and ramps.
• Ensure new walkways and sidewalks are clear of any
obstructions, including utilities, traffic control devices,
trees, and furniture.
• Design for seamless, multi-modal pedestrian connections,
making access easy, direct, and comfortable.
Additional Resources:
Metro Active Transportation Strategic Plan
Metro Complete Streets Policy
Metro First/Last Mile Strategic Plan
Metro Transit Supportive Planning Toolkit
The City of Santa Monica leveraged investments
in rail transit and reconfigured Colorado Avenue
to form a multi-modal first/last mile gateway to
the waterfront from the Expo Line Station.
Site Planning & Design 1
17 Metro Adjacent Development Handbook
1.3 Building Setback
Buildings and structures with a zero lot setback abutting Metro ROW
are of prime concern to Metro. Encroachment onto Metro property to
construct or maintain buildings is strongly discouraged as this
presents safety hazards and may disrupt transit service and/or
damage Metro infrastructure.
Recommendation:Metro strongly encourages development plans
include a minimum setback of five (5) feet to buildings from the
Metro ROW property line to accommodate the construction and
maintenance of structures without the need to encroach upon Metro
property. As local jurisdictions also have building setback
requirements, new developments should comply with the greater of
the two requirements.
Entry into the ROW by parties other than Metro and its affiliated
partners requires written approval. Should construction or
maintenance of a development necessitate temporary or ongoing
access to Metro ROW, a Metro Right of Entry Permit must be
requested and obtained from Metro Real Estate for every instance
access is required. Permission to enter the ROW is granted solely at
Metro’s discretion.
Refer to Section 3.2 –Track Access and Safety for additional
information pertaining to ROW access in preparation for construction
activities.
Additional Resources:
Metro Adjacent Construction Design Manual
A minimum setback of five (5) feet between an
adjacent structure and Metro ROW is strongly
encouraged.
Site Planning & Design 1
Metro Adjacent Development Handbook 18
1.4 Shared Barrier Construction &
Maintenance
In areas where Metro ROW abuts private property, barrier
construction and maintenance responsibilities can rise to be a
point of contention with property owners. When double barriers
are constructed, the gap created between the Metro-constructed
fence and a private property owner’s fence can accumulate trash
and make regular maintenance challenging without accessing the
other party’s property.
Recommendation: Metro strongly prefers a single barrier condition
along its ROW property line. With an understanding that existing
conditions along ROW boundaries vary throughout Los Angeles
County, Metro recommends the following, in order of preference:
1. Enhance existing Metro barrier: if structural capacity allows,
private property owners and developers should consider
physically affixing improvements onto and building upon
Metro’s existing barrier. Metro is amenable to barrier
enhancements such as increasing barrier height and allowing
private property owners to apply architectural finishes to their
side of Metro’s barrier.
2. Replace existing barrier(s): if conditions are not desirable,
remove and replace any existing barrier(s), including Metro’s,
with a new single barrier built on the property line.
Metro is amenable to sharing costs for certain improvements that
allow for clarity in responsibilities and adequate ongoing maintenance
from adjacent property owners without entering Metro’s property.
Metro Real Estate should be contacted with case-specific questions
and will need to approve shared barrier design, shared-financing, and
construction.
Double barrier conditions allow trash
accumulation and create maintenance
challenges for Metro and adjacent property
owners.
Metro prefers a single barrier condition along its
ROW property line.
Site Planning & Design 1
19 Metro Adjacent Development Handbook
1.5 Project Orientation & Noise Mitigation
Metro may operate in and out of revenue service 24 hours per day,
every day of the year, and can create noise and vibration (i.e. horns,
power washing). Transit service and maintenance schedules cannot
be altered to avoid noise for adjacent developments. However, no ise
and vibration impacts can be reduced through building design and
orientation.
Recommendations: Use building orientation, programming, and
design techniques to reduce noise and vibration for buildings along
Metro ROW:
• Locate “back of house” rooms (e.g. bathrooms, stairways,
laundry rooms) along ROW, rather than noise sensitive rooms
(e.g. bedrooms and family rooms)
• Use upper level setbacks and locate living spaces away from
ROW.
• Enclose balconies.
• Install double-pane windows.
• Include language disclosing potential for noise, vibration, and
other impacts due to transit proximity in terms and conditions
for building lease/sale agreements to protect building
owners/sellers from tenant/buyer complaints.
Developers are responsible for any noise mitigation required, which
may include engineering designs for mitigation recommended by
Metro or otherwise required by local municipalities. A recorded Noise
Easement Deed in favor of Metro may be required for projects within
100’ of Metro ROW to ensure notification to tenants and owners of
any proximity issues.
Additional Resources:
Noise Easement Deed
MRDC, Section 2 – Environmental Considerations
Building orientation can be designed to face
away from tracks, reducing the noise and
vibration impacts.
Strategic placement of podiums and upper-
level setbacks on developments near Metro
ROW can reduce noise and vibration impacts.
Site Planning & Design 1
Metro Adjacent Development Handbook 20
1.6 Sightlines at Crossings
Developments adjacent to Metro ROW can present visual barriers to
transit operators approaching vehicular and pedestrian crossings.
Buildings and structures in close proximity to transit corridors can
reduce sightlines and create blind corners where operators cannot see
pedestrians. This requires operations to reduce train speeds, which
decreases the efficiency of transit service.
Recommendation: Design buildings to maximize transit service
sightlines at crossings, leaving a clear cone of visibility to oncoming
vehicles and pedestrians. Metro Operations will review, provide
guidance, and determine the extent of operator visibility for safe
operations. If the building envelope overlaps with the visibility cone
near pedestrian and vehicular crossings, a building setback may be
needed to ensure safe transit service. The cone of visibility at
crossings and required setback will be determined based on vehicle
approach speed.
Additional Resources:
MRDC, Section 4 – Guideway and Trackwork
MRDC, Section 12 – Safety, Security, & System Assurance
Limited sightlines for trains approaching street
crossings create unsafe conditions.
Visibility cones allow train operators to respond
to safety hazards.
Site Planning & Design 1
21 Metro Adjacent Development Handbook
1.7 Transit Envelope Clearance
Metro encourages density along and around transit service as well as
greening of the urban environment through the addition of street
trees and landscaping. However, building appurtenances, such as
balconies, facing rail ROW may pose threats to Metro service as
clothing or other décor could blow into the OCS. Untended
landscaping and trees can also grow into the OCS above light rail
lines, creating electrical safety hazards as well as visual and physical
impediments for trains.
Recommendation:Project elements facing or located adjacent to the
ROW should be designed to avoid potential conflicts with Metro
transit vehicles and infrastructure. Metro recommends that projects:
• Maintain building appurtenances and landscaping at a
minimum distance of ten (10) feet from the OCS and support
structures.
• Plan for landscape maintenance from private property and not
allow growth into the Metro ROW. Property owners will not be
permitted to access Metro property to maintain private
development.
• Design buildings such that balconies do not provide direct
access to ROW access.
Additional Resources:
MRDC, Section 4 – Guideway and Trackwork
MRDC, Section 6 – Architectural
MRDC, Section 12 – Safety, Security, & System Assurance
Adjacent structures and landscaping should be sited
to avoid conflicts with the rail OCS.
Site Planning & Design 1
Metro Adjacent Development Handbook 22
1.8 Bus Stops & Zones Design
Metro Bus serves 15,967 bus stops throughout the diverse
landscape that is Los Angeles County. Typically located on
sidewalks within the public right-of-way owned and maintained by
local jurisdictions, existing bus stop conditions vary from well-lit
and sheltered spaces to uncomfortable and unwelcoming zones.
Metro is interested in working with developers and local
jurisdiction to create a vibrant public realm around new
developments by strengthening multi-modal access to/from
Metro transit stops and enhancing the pedestrian experience.
Recommendation:When designing around existing or proposed bus
stops, Metro recommends project teams:
• Review Metro’s Transit Service Policy: Appendix D, which
provides standards for design and operation of bus stops and
zones for near-side, far-side, and mid-block stops. In particular,
adjacent projects should:
o Accommodate 6’ x 8’ landing pads at bus doors.
o Install a concrete bus pad within each bus stop zone to
avoid asphalt damage.
• Replace stand-alone bus stop signs with bus shelters that
include benches and adequate lighting.
• Design wide sidewalks (15’ preferred) that accommodate bus
landing pads as well as street furniture, landscape, and user
travel space.
• Ensure final design of stops and surrounding sidewalk allows
passengers with disabilities a clear path of travel.
• Place species of trees in quantities and spacing that will provide
a continuous shade canopy in paths of travel to access transit
stops. These must be placed far enough away from the curb and
adequately maintained to prevent visual and physical
impediments for buses when trees reach maturity.
• Locate and design driveways to avoid conflicts with on -street
services and pedestrian traffic.
Additional Resources:
Metro Transit Service Policy
Well-designed and accessible bus stops are
beneficial amenities for both transit riders and users
of adjacent developments.
Site Planning & Design 1
Sidewalk finish at stop
Bus sign located per city and
bus operation requirements
Minimum overhead
clearance
8’ clear sidewalk to accommodate
8’ x 5’ pad at bus doors
4’ minimum at
shelter structure
23 Metro Adjacent Development Handbook
1.9 Driveways/Access Management
Driveways adjacent to on-street bus stops can create conflict for
pedestrians walking to/from or waiting for transit. Additionally,
driveways accessing parking and loading at project sites near
Metro Rail and BRT crossings can create queuing issues along city
streets and put vehicles in close proximity with fast moving trains
and buses.
Recommendation:Metro encourages new developments to promote a
lively public space mutually beneficial to the project and Metro by
providing safe, comfortable, convenient, and direct connections to
transit. Metro recommends that projects:
• Place driveways along side streets and alleys, away from on-
street bus stops and transit crossings to minimize safety
conflicts between active tracks, transit vehicles, and people, as
well as queuing on streets.
• Locate vehicular driveways away from transit crossings or
areas that are likely to be used as waiting areas for transit
services.
• Program loading docks away from sidewalks where transit bus
stop activity is/will be present.
• Consolidate vehicular entrances and reduce width of
driveways.
• Raise driveway crossings to be flush with the sidewalk,
slowing automobiles entering and prioritizing pedestrians.
• Separate pedestrian walkways to minimize conflict with
vehicles and encourage safe non-motorized travel.
Additional Resources:
Metro First/Last Mile Strategic Plan
MRDC, Section 3 – Civil
Driveways in close proximity to each other
compromise safety for those walking to/from
transit and increase the potential for vehicle-
pedestrian conflicts.
A consolidated vehicular entrance greatly
reduces the possibility for vehicle-pedestrian
conflicts.
Site Planning & Design 1
Metro Adjacent Development Handbook 24
25 Metro Adjacent Development Handbook
Metro Adjacent Development Handbook 26
Engineering 2
27 Metro Adjacent Development Handbook
2.1 Excavation Support System Design
Excavation near Metro ROW has the potential to disturb adjoining
soils and jeopardize the support of existing Metro infrastructure. Any
excavation which occurs within the geotechnical foul zone is subject
to Metro review and approval. The geotechnical zone of influence
shall be defined as the area below the track-way as measured from a
45-degree angle from the edge of the rail track ballast. Construction
within this vulnerable area poses a potential risk to Metro service and
safety and triggers additional safety regulations.
Recommendation:Coordinate with Metro Engineering staff for review
and approval of structural and support of excavation drawings prior to
the start of excavation or construction. Tie backs encroaching into
Metro ROW may require a tie back easement or license, at Metro’s
discretion.
Any excavation/shoring within Metrolink operated and maintained
ROW would require compliance with Metrolink Engineering standards
and guidelines.
Additional Resources:
Metrolink Engineering & Construction Requirements
MRDC, Section 3 – Civil
MRDC, Section 5 – Structural/Geotechnical
An underground structure located within the
ROW foul zone would require additional review
by Metro.
Engineering 2
Metro Adjacent Development Handbook 28
2.2 Proximity to Stations & Tunnels
Metro supports development of commercial and residential
properties near transit services and understands that increasing
development near stations represents a mutually beneficial
opportunity to increase ridership and enhance transportation
options for the users of the developments. However, construction
adjacent to, over, or under underground Metro facilities (tunnels,
stations and appendages) is of great concern and should be
coordinated closely with Metro Engineering.
Recommendation:Dependent on the nature of the adjacent
construction, Metro will need to review the geotechnical report,
structural foundation plans, sections, shoring plan sections and
calculations. Metro typically seeks to maintain a minimum eight
(8) foot clearance from existing Metro facilities to new
construction (shoring or tiebacks). It will be incumbent upon the
developer to demonstrate, to Metro’s satisfaction, that both the
temporary support of construction and the permanent works do
not adversely affect the structural integrity, safety or continued
efficient operation of Metro facilities.
Metro may require monitoring where such work will either
increase or decrease the existing overburden (i.e. weight) to which
the tunnels or facilities are subjected. When required, the
monitoring will serve as an early indication of excessive structural
strain or movement. Additional information regarding monitoring
requirements, which will be determined on a case-by-case basis,
may be found in Section 3.4, Excavation Drilling/Monitoring.
Additional Resources:
MRDC, Section 3 – Civil
MRDC, Section 5 – Structural/Geotechnical
Underground tunnels in close proximity to
adjacent basement structure.
Engineering 2
29 Metro Adjacent Development Handbook
2.3 Protection from Explosion/Blast
Metro is obligated to ensure the safety of public transit infrastructure
from potential explosive sources which could originate from adjacent
underground structures or from at grade locations, situated below
elevated guideways or stations. Blast protection setbacks or
mitigation may be required for large projects constructed near critical
Metro facilities.
Recommendation:Avoid locating underground parking or basement
structures within twenty (20) feet from an existing Metro tunnel or
facility (exterior face of wall to exterior face of wall). Adjacent
developments which are within this 20-foot envelope may be required
to undergo a Threat Assessment and Blast/Explosion Study subject to
Metro review and approval.
Additional Resources:
Metro Adjacent Construction Design Manual
MRDC, Section 3 – Civil
MRDC, Section 5 – Structural/Geotechnical
An underground structure proposed within
twenty (20) feet of a Metro structure may
require a threat assessment and blast/explosion
study.
Engineering 2
Metro Adjacent Development Handbook 30
31 Metro Adjacent Development Handbook
Metro Adjacent Development Handbook 32
Construction Safety
& Monitoring 3
33 Metro Adjacent Development Handbook
3.1 Pre-Construction Coordination
Metro is concerned with impacts on service requiring single tracking,
line closures, speed restrictions, and bus bridging occurring as a
result of adjacent project construction. Projects that will require work
over, under, adjacent, or on Metro property or ROW and include
operation of machinery, scaffolding, or any other potentially
hazardous work are subject to evaluation in preparation for and
during construction to maintain safe operations and passenger
wellbeing.
Recommendation:Following an initial screening of the project,
additional coordination may be determined to be necessary.
Dependent on the nature of the adjacent construction, developers
may be requested to perform the following as determined on a case-
by-case basis:
• Submit a construction work plan and related project drawings
and specifications for Metro review.
• Submit a contingency plan, show proof of insurance coverage,
and issue current certificates.
• Provide documentation of contractor qualifications.
• Complete pre-construction surveys, perform baseline readings,
and install movement instrumentation.
• Complete readiness review and perform practice run of
shutdown per contingency plan.
• Confirm a ROW observer or other safety personnel and an
inspector from the parties.
• Establish a coordination process for access and work in or
adjacent to ROW for the duration of construction.
Project teams will be responsible for the costs of adverse impacts
on Metro transit operations caused by work on adjacent
developments, including remedial work to repair damage to
Metro property, facilities, or systems. Additionally, a review fee
may be assed based on an estimate of required level of effort
provided by Metro.
All projects adjacent to Metrolink infrastructure will require
compliance with SCRRA Engineering Standards and Guidelines.
Metro staff oversees construction for the Purple
Line extension.
Additional Resources:
Metrolink Engineering & Construction
Requirements
Metro Adjacent Construction Design
Manual
Construction Safety & Monitoring 3
Metro Adjacent Development Handbook 34
3.2 Track Access and Safety
Permission is needed from Metro to enter Metro property for
construction and maintenance along, above, or under Metro ROW as
these activities can interfere with Metro utilities and service and pose
a safety hazard to construction teams and transit riders. Track access
is solely at Metro’s discretion and is discouraged to prevent
electrocution and collisions with construction workers or machines.
Recommendation:To work in or adjacent to Metro ROW, the
following must be obtained and/or completed:
• Right-of-Entry Permit/Temporary Construction Easement: All
access to and activity on Metro property, including easements
necessary for construction of adjacent projects, must be
approved through a Right-of-Entry Permit and/or a Temporary
Construction Easement obtained from Metro Real Estate and
may require a fee.
• Track Allocation: All work on Metro Rail ROW must receive prior
approval from Metro Rail Operations Control. Track Allocation
identifies, reserves, and requests changes to normal operations
for a specific track section, line, station, location, or piece of
equipment to allow for safe use by a non-Metro entity.
• Safety Training: All members of the project construction team
will be required to attend Metro Safety Training in advance of
work activity.
• Construction Work Plan: Dependent on the nature of adjacent
construction, Metro may request a construction work plan,
which describes means and methods and other construction
plan details, to ensure the safety of transit operators and
patrons.
Additional Resources:
Metro Adjacent Construction Design Manual
Safety Training
Track Allocation
Trained flaggers ensure the safe crossing of
pedestrians and workers of an adjacent
development.
Construction Safety & Monitoring 3
35 Metro Adjacent Development Handbook
3.3 Construction Hours
To maintain public safety and access for Metro riders, construction
should be planned, scheduled, and carried out in a way to avoid
impacts to Metro service and maintenance. Metro may limit hours of
construction which impact Metro ROW to night or off-peak hours so
as not to interfere with Metro revenue service.
Recommendations:In addition to receiving necessary construction
approvals from the local municipality, all construction work on or in
close proximity to Metro ROW must be scheduled through the Track
Allocation Process, detailed in Section 3.2.
Metro prefers that adjacent construction that has the potential to
impact normal, continuous Metro operations take place during non -
revenue hours (approximately 1:00a.m.-4:00a.m.) or during non-peak
hours to minimize impacts to service. The project sponsor may be
responsible for additional operating costs resulting from disruption to
normal Metro service.
Additional Resources:
Metro Adjacent Construction Design Manual
MRDC, Section 10 – Operations
Track Allocation
Construction during approved hours ensures the
steady progress of adjacent development
construction as well as performance of Metro’s
transit service.
Construction Safety & Monitoring 3
Metro Adjacent Development Handbook 36
3.4 Excavation/Drilling Monitoring
Excavation is among the most hazardous construction activities and
can pose threats to the structural integrity of Metro’s transit
infrastructure.
Recommendation:Excavation and shoring plans adjacent to the
Metro ROW shall be reviewed and approved by Metro Engineering
prior to commencing construction.
Geotechnical instrumentation and monitoring will be required for all
excavations occurring within Metro’s geotechnical zone of influence,
where there is potential for adversely affecting the safe and efficient
operation of transit vehicles. Monitoring of Metro facilities due to
adjacent construction may include the following as determined on a
case-by-case basis:
• Pre- and post-construction condition surveys
• Extensometers
• Inclinometers
• Settlement reference points
• Tilt-meters
• Groundwater observation wells
• Movement arrays
• Vibration monitoring
Additional Resources:
Metro Adjacent Construction Design Manual
MRDC, Section 3 – Civil
MRDC, Section 5 – Structural/Geotechnical
Rakers and tiebacks provide temporary support
during construction.
A soldier pile wall supports adjacent land during
construction.
Construction Safety & Monitoring 3
37 Metro Adjacent Development Handbook
3.5 Crane Operations
Construction activities adjacent to Metro ROW will often require
moving large, heavy loads of building materials and machinery by
cranes. Cranes referred to in this section include all power operated
equipment that can hoist, lower, and horizontally move a suspended
load. There are significant safety issues to be considered for the
operators of crane devices as well as Metro patrons and operators.
Recommendations:Per California Occupational Safety and Health
Administration (Cal/OSHA) standards, cranes operated near the OCS
must maintain a twenty (20) foot clearance from the OCS. In the
event that a crane or its load needs to enter the 20-foot envelope, OCS
lines must be de-energized.
Construction activities which involve swinging a crane and suspended
loads over Metro facilities or bus passenger areas shall not be
performed during revenue hours. The placement and swing of this
equipment are subject to Metro review and possible work plan.
Additional Resources:
Metro Adjacent Construction Design Manual
Cal/OSHA
Construction adjacent to the Pico Rail Station in
Downtown Los Angeles.
Construction adjacent to the Chinatown Rail
Station.
Construction Safety & Monitoring 3
Metro Adjacent Development Handbook 38
3.6 Construction Barriers & Overhead
Protection
During construction, falling objects can damage Metro facilities, and
pose a safety concern to the patrons accessing them.
Recommendations:Vertical construction barriers and overhead
protection compliant with Metro and Cal OSHA requirements shall be
constructed to prevent objects from falling into the Metro ROW or
areas designed for public access to Metro facilities. A protection
barrier shall be constructed to cover the full height of an adjacent
project and overhead protection from falling objects shall be provided
over Metro ROW as necessary. Erection of the construction barriers
and overhead protection for these areas shall be done during Metro
non-revenue hours.
Additional Resources:
Metro Adjacent Construction Design Manual
A construction barrier is built at the edge of the
site to protect tracks from adjacent work.
Construction Safety & Monitoring 3
39 Metro Adjacent Development Handbook
3.7 Pedestrian & Emergency Access
Metro’s ridership relies on the consistency and reliability of access
and wayfinding to/from stations, stops, and facilities. Construction on
adjacent developments must not obstruct fire department access,
emergency egress, or otherwise present a safety hazard to Metro
operations, its employees, patrons, and the general public. Fire access
and safe escape routes within all Metro stations, stops, and facilities
must be maintained.
Recommendations:The developer shall ensure pedestrian access to
Metro stations, stops, and transit facilities is compliant with the
Americans with Disabilities Act (ADA) and maintained during
construction:
• Temporary fences, barricades, and lighting should be installed
and watchmen provided for the protection of public travel, the
construction site, adjacent public spaces, and existing Metro
facilities.
• Temporary signage should be installed where necessary and in
compliance with the latest California Manual on Uniform Traffic
Control Devices and in coordination with Metro Art and Design
Standards.
• Emergency exists shall be provided and be clear of obstructions
at all times.
• Access shall be maintained for utilities such as fire hydrants,
stand pipes/connections, and fire alarm boxes as well as Metro-
specific infrastructure such as fan and vent shafts.
Additional Resources:
California Manual on Uniform Traffic Control Devices
Metro Adjacent Construction Design Manual
Metro Signage Standards
Sidewalk access is blocked for construction
project, forcing pedestrians into street or to use
less direct paths to the Metro facility.
Construction Safety & Monitoring 3
Metro Adjacent Development Handbook 40
3.8 Impacts to Bus Routes & Stops
During construction, bus stops and routes may need to be
temporarily relocated. Metro needs to be informed of activities that
require removal and/or relocation in order to ensure uninterrupted
service.
Recommendations:During construction, existing bus stops must be
maintained or relocated consistent with the needs of Metro Bus
Operations. Design of temporary and permanent bus stops and
surrounding sidewalk area must be ADA-compliant and allow
passengers with disabilities a clear path of travel to the transit service.
Metro Bus Operations Control Special Events and Metro Stops &
Zones Department should be contacted at least 30 days in advance of
initiating construction activities
Additional Resources:
Metro Transit Service Policy
MRDC, Section 3 – Civil
Temporary and permanent relocation of bus
stops and layover zones will require
coordination between developers, Metro, and
other municipal bus operators, and local
jurisdictions.
Construction Safety & Monitoring 3
41 Metro Adjacent Development Handbook
3.9 Utility Coordination
Construction has the potential to interrupt utilities that Metro relies
on for safe operations and maintenance. Utilities of concern to Metro
include but are not limited to: condenser water piping, potable/fire
water, and storm and sanitary sewer lines, as well as
electrical/telecommunication services.
Recommendations:Temporary and permanent utility impacts and
relocation near Metro facilities should be addressed during project
design and engineering to avoid conflicts during construction.
The contractor shall protect existing aboveground and underground
Metro utilities during construction and coordinate with Metro to
receive written approval for any utilities pertinent to Metro facilities
that may be verified, used, interrupted, or disturbed.
When electrical power outages or support functions are required, the
approval must be obtained through Metro Track Allocation.
Additional Resources:
Metro Adjacent Construction Design Manual
Coordination of underground utilities is critical.
Construction Safety & Monitoring 3
Metro Adjacent Development Handbook 42
3.10 Air Quality & Ventilation Protection
Hot or foul air, fumes, smoke, steam, and dust from adjacent
construction activities can negatively impact Metro facilities, service,
and users.
Recommendation:Hot or foul air, fumes, smoke, and steam from
adjacent facilities must not be discharged within 40 feet of existing
Metro facilities, including but not limited to: ventilation system intake
shafts or station entrances. Should fumes be discharged within 40
feet of Metro intake shafts, a protection panel around each shaft shall
be required.
Additional Resources:
Metro Adjacent Construction Design Manual
MRDC, Section 8 – Mechanical
A worker breaks up concrete creating a cloud of
silica dust.
Construction Safety & Monitoring 3
43 Metro Adjacent Development Handbook
Metro encourages developers and
municipalities to leverage digital resources and
data sets to maximize opportunities inherent in
transit adjacency.
The following provides Metro contact information and a list of programs,
policies, and online resources that should be considered when planning
projects within 100 feet of Metro ROW – including underground easements
– and in close proximity to non-revenue transit facilities and property:
Metro Adjacent Development
Contact Information & Resources
Please direct any questions to the Metro Adjacent Development team at:
• 213-418-3484
• DevReview@metro.net
Metro Adjacent Development Review Webpage:
https://www.metro.net/projects/devreview/
Metro Right-of-Way GIS Data
Metro maintains a technical resource website housing downloadable data
sets and web services. Developers and municipalities should utilize
available Metro right-of-way GIS data to appropriately plan and coordinate
with Metro when proposing projects within 100’ of Metro right-of-way:
https://developer.metro.net/portfolio-item/metro-right-of-way-gis-data/
Metro Design Criteria & Standards
Metro standard documents are periodically updated and are available upon
request:
• Metro Adjacent Construction Design Manual
• Metro Rail Design Criteria (MRDC)
• Metro Rail Directive Drawings
• Metro Rail Standard Drawings
• Metro Signage Standards
Resources
Metro Adjacent Development Handbook 44
Metrolink Standards & Procedures
Engineering & Construction
https://www.metrolinktrains.com/about/agency/engineering--
construction/
Metro Policies & Plans
Active Transportation Strategic Plan, 2016
https://www.metro.net/projects/active-transportation-strategic-plan/
Complete Streets Policy, 2014
https://www.metro.net/projects/countywide-planning/metros-complete-
streets-policy-requirements/
Countywide Sustainability Planning Policy & Implementation Plan, 2012
https://media.metro.net/projects_studies/sustainability/images/countywid
e_sustainability_planning_policy.pdf
First/Last Mile Strategic Plan, 2014
https://media.metro.net/docs/First_Last_Mile_Strategic_Plan.pdf
Transit Service Policy, 2015
https://media.metro.net/images/service_changes_transit_service_policy.p
df
Major construction at the Metrolink San
Bernardino Station.
Metro Complete Streets Policy
45 Metro Adjacent Development Handbook
Metro Bike Hub at Los Angeles Union Station
Metro Programs & Toolkits
Bike Hub
https://bikehub.com/metro/
Bike Share for Business
https://bikeshare.metro.net/for-business/
Green Places Toolkit
https://www.metro.net/interactives/greenplaces/index.html
Transit Oriented Communities
https://www.metro.net/projects/transit-oriented-communities/
Transit Passes
Annual and Business Access Passes
https://www.metro.net/riding/eapp/
College/Vocational Monthly Pass
https://www.metro.net/riding/fares/collegevocational/
Transit Supportive Planning Toolkit
https://www.metro.net/projects/tod-toolkit/
Useful Policies & Resources
ADA Standards for Accessible Design, 2010
U.S. Department of Justice.
https://www.ada.gov/2010ADAstandards_index.htm
California Manual on Uniform Traffic Control Devices.
State of California Department of Transportation
http://www.dot.ca.gov/trafficops/tcd/signcharts.html
California Occupational Safety and Health Administration (Cal/OSHA)
State of California Department of Industrial Relations
http://www.dir.ca.gov/dosh/
Resources Resources
Metro Adjacent Development Handbook 46
47 Metro Adjacent Development Handbook
Cone of Visibility – a conical space at the front of moving
transit vehicles allowing for clear visibility of travel way
and/or conflicts.
Construction Work Plan (CWP) – project management
document outlining the definition of work tasks, choice of
technology, estimation of required resources and
duration of individual tasks, and identification of
interactions among the different work tasks.
Flagger/Flagman – person who controls traffic on and
through a construction project. Flaggers must be trained
and certified by Metro Rail Operations prior to any work
commencing in or adjacent to Metro ROW.
Geotechnical Foul Zone – area below a track-way as
measured from a 45-degree angle from the edge of the
rail track ballast.
Guideway – a channel, track, or structure along which a
transit vehicle moves.
Heavy Rail Transit (HRT) – Metro HRT systems include
exclusive ROW (mostly subway) trains up to six (6) cars
long (450’) and utilize a contact rail for traction power
distribution (e.g. Metro Red Line).
Light Rail Transit (LRT) – Metro LRT systems include
exclusive, semi-exclusive, or street ROW trains up to
three (3) cars long (270’) and utilize OCS for traction
power distribution (e.g. Metro Blue Line).
Measure R – half-cent sales tax for Los Angeles County
approved in November 2008 to finance new
transportation projects and programs. The tax expires in
2039.
Measure M – half-cent sales tax for LA County approved
in November 2016 to fund transportation improvements,
operations and programs, and accelerate projects already
in the pipeline. The tax will increase to one percent in
2039 when Measure R expires.
Metrolink – a commuter rail system with seven lines
throughout Los Angeles, Orange, Riverside, San
Bernardino, Ventura, and North San Diego counties
governed by the Southern California Regional Rail
Authority.
Metro Adjacent Construction Design Manual – Volume III
of the Metro Design Criteria & Standards which outlines
the Metro adjacent development review procedure as well
as operational requirements when constructing over,
under, or adjacent to Metro facilities, structures, and
property.
Metro Bus – Metro “Local” and “Rapid” bus service runs
within the street, typically alongside vehicular traffic,
though occasionally in “bus-only” lanes.
Metro Bus Rapid Transit (BRT) – high quality bus service
that provides faster and convenient service through the
use of dedicated ROW, branded vehicles and stations,
high frequency and intelligent transportation systems, all
door boarding, and intersection crossing priority. Metro
BRT generally runs within the center of freeways and/or
within dedicated corridors.
Metro Design Criteria and Standards – a compilation of
documents that govern how Metro transit service and
facilities are designed, constructed, operated, and
maintained.
Metro Rail – urban rail system serving Los Angeles
County consisting of six lines, including two subway lines
(Red and Purple Lines) and four light rail lines (Blue,
Green, Gold, and Expo Lines).
Metro Rail Design Criteria (MRDC) – Volume IV of the
Metro Design Criteria & Standards which establishes
design criteria for preliminary engineering and final
design of a Metro Project.
Metro Transit Oriented Communities – land use planning
and community development program that seeks to
Glossary
Metro Adjacent Development Handbook 48
maximize access to transportation as a key organizing
principle and promote equity and sustainable living by
offering a mix of uses close to transit to support
households at all income levels, as well as building
densities, parking policies, urban design elements and
first/last mile facilities that support ridership and reduce
auto dependency.
Noise Easement Deed – easement completed by property
owners abutting Metro ROW acknowledging use and
possible results of transit vehicle operation on the ROW.
Overhead Catenary System (OCS) – one or more
electrified wires (or rails, particularly in tunnels) situated
over a transit ROW that transmit power to light rail trains
via pantograph, a current collector mounted on the roof
of an electric vehicle. Metro OCS is supported by hollow
poles placed between tracks or on the outer edge of
parallel tracks.
Right of Entry Permit – written approval granted by Metro
Real Estate to enter Metro ROW and property.
Right of Way (ROW) –the composite total requirement of
all interests and uses of real property needed to
construct, maintain, protect, and operate the transit
system.
Southern California Regional Rail Authority (SCRRA) – a
joint powers authority made up of an 11-member board
representing the transportation commissions of Los
Angeles, Orange, Riverside, San Bernardino and Ventura
counties. SCRRA governs and operates Metrolink service.
Threat Assessment and Blast/Explosion Study – analysis
performed when adjacent developments are proposed
within twenty (20) feet from an existing Metro tunnel or
facility.
Track Allocation/Work Permit – permit granted by Metro
Rail Operations Control to allocate a section of track and
perform work on Metro Rail ROW. This permit should be
submitted for any work that could potentially foul the
envelope of a train.
Wayfinding – signs, maps, and other graphic or audible
methods used to convey location and directions to
travelers.
6d
SANITATION DISTR ICTS OF LOS ANGELES COUNTY
~
Converting Waste Into Resources
Ms. Grace S. Lee, Senior Planner
Planning Division
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
Dear Ms. Lee:
Robert C. Ferrante
Chief Engineer and General Manager
1955 Workman Mill Road , Whittier, CA 90601-1400
Mailing Address: P.O . Box 4998 , Whittier, CA 90607-4998
(562) 699-7411 • www.lacsd.org
October 3 I , 2019
Ref. DOC 5311089
DEIR Response to the Diamond Bar
Comprehensive General Plan Update and Climate Action Plan
The Sanitation Districts of Los Angeles County (Districts) received a Draft Environmental Impact
Report (DEIR) for the subject project on September 20 , 2019. The City of Diamond Bar (City) is located
within the jurisdictional boundaries of District No . 21. We offer the following comments :
1. Future Development , page 2-26, paragraph one -The Districts should review individual
developments within the City in order to determine whether or not sufficient trunk sewer capacity
exists to serve each project and if Districts ' facilities will be affected by the project.
2 . Table 2.3-2 , page 2-26, Projected Residential Buildout and Population (2040) -The table lists
3,264 housing units as future development within the City and breaks it down to 142 single-family
residential units and 3,122 multi-family residential units . The expected average wastewater flow
from 142 single family homes is 36,920 gallons per day (gpd). Depending on the type of multi-
family unit , the expected average wastewater flow from 3,122 multi-family residential units could
range from 487 ,032 gpd to 608 ,790 gpd . For a copy of the Districts ' average wastewater generation
factors , go to www.lacsd.org . Wastewater & Sewer Systems , click on Will Serve Program , and
click on the Table 1, Loadings for Each Class of Land Use link .
3 . Table 2.3-3 , page 2-26, Projected Residential Buildout and Population (2040) -The table breaks
down non-residential by square feet listin g future development as 607 ,283 square feet of retail
development, 519,892 square feet of office space , removal of203 ,00I square feet of industrial use
structure, and 693 ,409 square feet within the "other" category . The expected average wastewater
flow for the non -residential future development is 400 ,282 gpd, after all scheduled industrial
structures on the project site are demolished .
4. Impact 3 .6-5 ,page 3. 6-32 , paragraph four-It should also be noted that the Districts are empowered
by the California Health and Safety Code to charge a fee for the privilege of connecting (directly
or indirectly) to the Districts' Sewerage System for increasing the strength or quantity of
wastewater discharged from connected facilities . This connection fee is a capital facilities fee that
DOC 536 1522.D2 l
Printed on •~
Recycled Paper t.:
Ms. Grace S . Lee -2-October 3 I , 2019
is imposed in an amount sufficient to construct an incremental expansion of the Sewerage System
to accommodate the proposed project. Payment of a connection fee will be required before this
project is permitted to discharge to the Districts ' Sewerage System.
All other information concerning Districts ' facilities and sewerage service contained in the
document is current. If you have any question s, please contact the undersigned at (562) 908-4288 ,
extension 2717 .
AR:ar
DOC 536 I 522 .02 1
Very truly yours,
tf+rlucm/L
Adriana Raza
Customer Service Specialist
Facilities Planning Depa,tment
Diamond Bar General Plan EIR comment
October 8, 2019
Section 3 Transit Noise, Section 3.1 Noise of the 2018 Metrics Transit Noise and Vibration Impact
Assessment Manual by the Federal Transit Administration:
Railroad sound levels were measured using A-weighting that approximates typical human hearing and
reported as dBA from the Google Earth reported distance from the railroad tracks with passing
locomotives and rail cars to the receiving location near the intersection of N. Rock River Dr. and Red
Cloud Dr. in Diamond Bar. The actual Sound Level Exposure (SEL) 50 feet from the source would
require additional information and calculations or measurement at the source, which is easier than
calculations. Note that Table 3-1 describes a human-perceived 10 dB increase above the actual
measurements between 10 p.m. and 7 a.m. Therefore, a sound level of 60 dBA would be perceived as
70 dBA, and a 10 dB increase is perceived as a doubling of sound levels by the human ear.
Section 3.3 Paths of Transit Noise from Source to Receiver
This section states: “Sound paths from source to receiver are predominantly through the air. Along
these paths, sound reduces with distance due to divergence, absorption/diffusion, and shielding.” Per
Figure 3-3 below, the approximate attenuation of the generator SEL at 50 feet would decrease by 20
dBA at 800 feet from the source and this is a logarithmic decrease. Instead of calculating the
attenuation, it is somewhat easier to extrapolate from Figure 3-3. It is estimated that there is a 30 dBA
attenuation at 2,000 feet from the source. However, when one considers Figure 3-4 attenuation over
soft ground, it is clear that height above terrain determines attenuation, and the neighborhoods south of
Dry Creek are more than 40 feet above the source and would have negligible sound level attenuation
by the ground. This corresponds reasonably well with trains passing west, northwest, and north of the
receiving location, but not trains passing further west by the warehouses along Ferrero Parkway in the
City of Industry. Direction of travel is critical in determining cumulative sound levels.
Figure 3-3 Attenuation Due to Distance (Divergence)
In the section on shielding, it is noted that noise barriers are one of the most effective means of
mitigating noise, such as a wall. Walls also reflect sound. When the City of Industry permitted
warehouses with flat vertical walls to be built along Ferrero Parkway near the Union Pacific Railroad
tracks, railroad sound was amplified and reflected south and southeast into the Diamond Bar
neighborhoods along Sunset Crossing Road and Prospectors Road. The noise intrudes into homes.
Figure 3-4 Attenuation Due to Soft Ground
Note that the time period when locomotives pass by those warehouses, sound is further amplified and
reflected. There is no mitigation of that reflected sound. Possible mitigation could include sound
deadening treatment of the warehouse walls. Further, when buildings are built on the flat-topped hill
south of the railroad tracks, railroad noise would be reflected to the northwest and north and then
reflected again off the walls of warehouses (in ellipse) along Ferrero Parkway. Whether phasing of that
sound will amplify or attenuate the railroad noise is unknown. Sound/noise mitigation is warranted.
When it comes to community annoyance to the noise, Figure 3-7 describes it well, and no further
discussion on annoyance is warranted.
Figure 3-7 Community Annoyance Due to Noise
Lastly, none of this means anything without actual data to assess the situation and how the Diamond
Bar 2040 General Plan Environmental Impact Report will address the situation. Since there is no
supporting data, I collected some from near the intersection of N. Rock River Dr. and Red Cloud Dr.
in Diamond Bar, as specified in the table below. Note the time of collection, the distance from the
railroad tracks, and the decibel measurements. It should be possible to estimate the noise levels at
distances closer to the passing trains.
Train Noise @ N. Rock River Dr. and Red Cloud Dr., Diamond Bar
Baseline Level < 50 dB A-Weighting 500 Hz – 10 kHz Fast
Date Time Location Distance (ft) Source Level (dBA)
9/15/19 0240 WB N. Track 3400 Train 56 dB max
9/15/19 0301-0306 EB S. Track 2100-2600 Train 56 dB - 64dB
9/16/19 0110 WB S. Track 2700 Train+Horn 75 dB
9/16/19 0146 WB S. Track 2400 Train 58 dB
9/16/19 0215 WB S. Track 2100-2700 Train 56 dB - 58dB
9/16/19 0220 WB S. Track 2400 Train 58 dB - 62 dB
9/16/19 0226 EB S. Track 2100-2700 Train 57 dB Sustain
Date Time Location Distance (ft) Source Level (dBA)
9/17/19 0050 WB N. Track 3400 Train+Horn 53 dB - 60 dB
9/17/19 0255 WB S. Track 2200 Train 60 dB
9/17/19 0300 WB S. Track 2400 Train 64 dB
9/17/19 0308 WB. S. Track 2400 Train 60 dB
9/17/19 0343-0347 WB/EB S. Track 2300 Train 58 dB - 62 dB
9/17/19 0359-0403 WB/EB S. Track 2300 Train 56 dB
9/17/19 1600 WB S. Track 2200 Train 57 dB
10/8/19 1118-1124 EB S. Track 2100-2700 Train * 52 dB – 62 dB
Measurement Equipment: Realistic Sound Level Meter No: 33-2050
* Note: The very long train on 10/8/2019 also had a locomotive in the middle and two at the end.
Freight trains have no posted schedule and pass at random times. During the measurement period,
there were no EB heavy load trains and no braking. Only one very loud horn was measured (9/16/2019
at 0110), and it was west of the receiving location and directed west. Levels hover around reported
values within 1-2 dB. Where levels are a range, the upper level is a peak.
Data captured and logged by Douglas Barcon
Submitted by:
Dr. Douglas Barcon
Diamond Bar General Plan 2040 and EIR Comment—Updated
October 9, 2019
The following is based on Section 3 Transit Noise; Section 3.1 Noise Metrics of the 2018 Transit
Noise and Vibration Impact Assessment Manual by the Federal Transit Administration, which was
provided as a reference in Chapter 3.10 Noise in the EIR and Chapter 7.8 in the 2040 General Plan.
Railroad sound levels were measured using A-weighting that approximates typical human hearing and
reported as dBA from the Google Earth reported distance from the railroad tracks with passing
locomotives and rail cars to the receiving location near the intersection of N. Rock River Dr. and Red
Cloud Dr. in Diamond Bar. The actual Sound Level Exposure (SEL) 50 feet from the source would
require additional information and calculations or measurement at the source, which is easier than
calculations. Note that Table 3-1 describes a human-perceived 10 dB increase above the actual
measurements between 10 p.m. and 7 a.m. Therefore, a sound level of 60 dBA would be perceived as
70 dBA, and a 10 dB increase is perceived as a doubling of sound levels by the human ear.
Section 3.3 Paths of Transit Noise from Source to Receiver
This section states: “Sound paths from source to receiver are predominantly through the air. Along
these paths, sound reduces with distance due to divergence, absorption/diffusion, and shielding.” Per
Figure 3-3 below, the approximate attenuation of the generator SEL at 50 feet would decrease by 20
dBA at 800 feet from the source and this is a logarithmic decrease. Instead of calculating the
attenuation, it is somewhat easier to extrapolate from Figure 3-3. It is estimated that there is a 30 dBA
attenuation at 2,000 feet from the source. However, when one considers Figure 3-4 attenuation over
soft ground, it is clear that height above terrain determines attenuation, and the neighborhoods south of
Dry Creek are more than 40 feet above the source and would have negligible sound level attenuation
by the ground. This corresponds reasonably well with trains passing west, northwest, and north of the
receiving location, but not trains passing further west by the warehouses along Ferrero Parkway in the
City of Industry. Direction of travel is critical in determining cumulative sound levels.
Figure 3-3 Attenuation Due to Distance (Divergence)
In the section on shielding, it is noted that noise barriers are one of the most effective means of
mitigating noise, such as a wall. Walls also reflect sound. When the City of Industry permitted
warehouses with flat vertical walls to be built along Ferrero Parkway near the Union Pacific railroad
tracks, railroad sound was amplified and reflected south and southeast into the Diamond Bar
neighborhoods along Sunset Crossing Road and Prospectors Road. The noise intrudes into homes.
Figure 3-4 Attenuation Due to Soft Ground
Note that the time period when locomotives pass by those warehouses, sound is further amplified and
reflected. There is no mitigation of that reflected sound. Possible mitigation could include sound
deadening treatment of the warehouse walls. Further, when buildings are built on the flat-topped hill
south of the railroad tracks, railroad noise would be reflected to the northwest and north and then
reflected again off the walls of warehouses (in ellipse) along Ferrero Parkway. Whether phasing of that
sound will amplify or attenuate the railroad noise is unknown. Sound/noise mitigation is warranted as
addressed in General Plan 2040 Chapter 7.8; policy PS-P-51 and Chapter 8.0; policy CHS-P-29.
When it comes to community annoyance to the noise, Figure 3-7 describes it well, and no further
discussion on annoyance is warranted.
Figure 3-7 Community Annoyance Due to Noise
Lastly, none of this means anything without actual data to assess the situation and how the Diamond
Bar 2040 General Plan Environmental Impact Report will address the situation. Since there is no
supporting data, I collected some from near the intersection of N. Rock River Dr. and Red Cloud Dr.
in Diamond Bar, as specified in the table below. Note the time of collection, the distance from the
railroad tracks, and the decibel measurements. It should be possible to estimate the noise levels at
distances closer to the passing trains, such as along Big Falls Drive and Strongbow Drive.
Train Noise @ N. Rock River Dr. and Red Cloud Dr., Diamond Bar
Baseline Level < 50 dB A-Weighting 500 Hz – 10 kHz Fast
Date Time Location Distance (ft) Source Level (dBA)
9/15/19 0240 WB N. Track 3400 Train 56 dB max
9/15/19 0301-0306 EB S. Track 2100-2600 Train 56 dB - 64dB
9/16/19 0110 WB S. Track 2700 Train+Horn 75 dB
9/16/19 0146 WB S. Track 2400 Train 58 dB
9/16/19 0215 WB S. Track 2100-2700 Train 56 dB - 58dB
9/16/19 0220 WB S. Track 2400 Train 58 dB - 62 dB
9/16/19 0226 EB S. Track 2100-2700 Train 57 dB Sustain
Date Time Location Distance (ft) Source Level (dBA)
9/17/19 0050 WB N. Track 3400 Train+Horn 53 dB - 60 dB
9/17/19 0255 WB S. Track 2200 Train 60 dB
9/17/19 0300 WB S. Track 2400 Train 64 dB
9/17/19 0308 WB. S. Track 2400 Train 60 dB
9/17/19 0343-0347 WB/EB S. Track 2300 Train 58 dB - 62 dB
9/17/19 0359-0403 WB/EB S. Track 2300 Train 56 dB
9/17/19 1600 WB S. Track 2200 Train 57 dB
10/8/19 1118-1124 EB S. Track 2100-2700 Train * 52 dB - 62 dB
Measurement Equipment: Realistic Sound Level Meter No: 33-2050
* Note: The very long train on 10/8/2019 also had a locomotive in the middle and two at the end.
There was a parallel train parked on the closer track that attenuated the noise level somewhat.
Freight trains have no posted schedule and pass at random times. During the measurement period,
there were no EB heavy load trains and no braking. Only one very loud horn was measured (9/16/2019
at 0110), and it was west of the receiving location and directed west. Levels hover around reported
values within 1-2 dB. Where levels are a range, the upper level is a peak.
As a final point, in Chapter 7.8 of the 2040 General Plan, Figure 7-11 on page 7-41, the map shows
existing noise contours in 2016 but does not show any railroad noise contour in the neighborhood
bordered by SR 57 on the east, City of Industry on the west, and the SR 57/SR 60 confluence on the
south. The same map is present in Chapter 3.10 of the EIR as Figure 3.10-2. The sound levels I
measured and noted in the table above show that this residential area should have a noise contour
included on the map and on the projected 2040 noise contour shown in Figure 7-12 on page 7-42 of the
General Plan and in Figure 3.10-2 (or a revision) in the EIR. I will postulate that the railroad noise
levels will decrease to the south of the highest points on Red Cloud Drive and Prospectors Road as
both roads descend.
Data captured and logged by Douglas Barcon
Submitted by:
Dr. Douglas Barcon
Diamond Bar Resident
Dr. Douglas Barcon
XXXX N. Rock River Dr.
Diamond Bar, CA 91765
Grace Lee
Senior Planner
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
October 29, 2019
Dear Grace,
Please add this additional information to my previous comment on railroad noise for the draft EIR.
Since I submitted my comment on the subject of railroad noise in Chapter 3.10 Noise in the EIR
and Chapter 7.8 in the 2040 General Plan, I was able to measure the sound levels of an additional
Union Pacific freight train early morning on October 24, 2019. This was one of the trains where
the locomotive horn was excessively loud and measured 82 dBA 2200 - 2500 feet from the source
locomotive, which was facing west away from the homes in Diamond Bar in the area around N.
Rock River Dr. and Red Cloud Dr. It was the loudest train horn I was able to measure. Occasional
other trains have a horn sound level that the human ear can sense is even louder. In comparison to
the 82 dBA sound level, I will estimate the loudest horn sound level to be in the range of 86 - 88
dBA. Some of these horns also sound at night when the ambient sound level is in the 40 dBA
range. There are no roads where the locomotives sound their horns, so a quiet zone designation
could mitigate the horn sounding without spending millions of dollars modifying intersections. A
quiet zone will not impact the other railroad noises.
Date Time Location Distance (ft) Source Level (dBA)
10/24/19 0143-0149 WB S. Track 2200 - 2500 Train 60 dB – 62 dB
Sustain + Horn
82 dB
Measurement Equipment: Realistic Sound Level Meter No: 33-2050
Respectfully,
Dr. Douglas Barcon
Data captured and logged by Douglas Barcon
Dr. Douglas Barcon
XXXX N. Rock River Dr.
Diamond Bar, CA 91765
Grace Lee
Senior Planner
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
October 31, 2019
Re: Draft Environmental Impact Report
Dear Ms. Lee,
I have been reviewing the draft Environmental Impact Report and have additional comments on
other topics beyond those I have previously submitted regarding railroad noise.
In the Executive Summary of the Draft Environmental Impact Report for the Diamond Bar
General Plan 2040 and Climate Action Plan Table ES-4: Summary of Impacts and Mitigation
Measurers in section 3.6 Geology, Soils, Seismicity, and Paleontology starting on page ES-46
shows no mitigation measures are necessary for section 3.6-3 Implementation of the Proposed
Project and would not result in significant development located on a geologic unit or soil that is
unstable, or that would become unstable as a result of the project, and potentially result in on- or
off-site landslide, lateral spreading, subsidence, liquefaction or collapse. I must question the
statement that mitigation is not necessary. Specifically, I am addressing the mixed-use area on
North Diamond Bar Boulevard between SR-60 and Sunset Crossing Road. This is the area next to
the Diamond Bar Boulevard exit from the westbound SR-60.
The area in question is shown in the excerpt Figure 3.6-1: Steep Slopes below.
Note the green areas (steep slopes) beside the Diamond Bar Boulevard off-ramp (red-brown) from
the WB SR-60 and along the right side of Diamond Bar Boulevard (gray line parallel to SR-57)
toward Sunset Crossing Road. There are homes at the top of those slopes. The beige area at the
off-ramp and extending to Sunset Crossing Road is flat land sandwiched between Diamond Bar
Boulevard and the steep slopes in green. This flat land has been incorporated into the North
Diamond Bar Boulevard mixed-use area. Civil engineers have previously stated that the slopes can
be damaged, and their stability compromised by cutting into them to develop the narrow ribbon of
flat land to the right of Diamond Bar Boulevard north of the off-ramp. Further, building a
driveway adjacent to a busy freeway off-ramp is a safety issue that can lead to collisions and
injuries. The flat land should remain as open space that could be landscaped, providing weeds on
the hillsides can be removed to mitigate fire danger to the houses above. Developers should not be
permitted to develop a property that jeopardizes the environment and creates a risk to others. Such
development of this property is also addressed in section 3.6-4, which also states no mitigation
measures are required. The direct risk is a possible collapse of the hillside by carving into it a non-
specified distance to enlarge the flat pad. This area should be removed from the mixed-use
designation in the General Plan Update and left as open space, perhaps with landscaping. Policies
LU-P-55, LU-P-56, PS-G-1, and PS-P-2 address some of this.
The colors shown in Figure 3.8-1: FEMA Flood Insurance Rate Map on page 3.8-5 are incorrect.
Diamond Bar is shown in white on the map, but the map key shows it is cream-colored. The key
currently indicates that white is a county boundary.
In Chapter 3.9: Land Use, Population, and Housing, the 2040 projections on page 3.9-7 state that
Diamond Bar’s population will increase to 66,685 residents from the current 57,853 residents or
an increase of 8,832 residents according to SCAG. At a population of 3.16 persons per occupied
unit, that equates to 2,795 new residential units. Where are these units going to be built, and what
is their impact on circulation, land use, and public safety? Transit-oriented-development and
mixed-use will accommodate some of these units. If the city intends to preserve open space, it may
not be possible with the SCAG projected growth.
Table 3.12-11: Commuter Mode Split in Diamond Bar and Surrounding Areas on page 3.12-4
indicates that Diamond Bar currently had 0.7% of the population commuting by bicycle and
walking compared to 3.6% in Los Angeles County. Figure 3.12-2: Proposed Bicycle Network on
page 3.12-11 is a map that shows the proposed bicycle network in Diamond Bar. The location of
Diamond Bar to jobs and the hilly area probably explains the variation. The likelihood of
bicycling and walking increasing by even 2 percent over the next 20 years is questionable
regardless of any state mandates. The state cannot dictate how a person commutes or travels.
The draft general plan has proposed bike lanes where bike travel is difficult, such as up Sunset
Crossing Road to Golden Springs Drive and up Gold Rush Drive from Diamond Bar Boulevard to
the top of the hill at Leyland. Traffic mitigation is also planned for Gold Rush Drive. Bicycle
riders are at risk of injury on either of these routes, and the likelihood of a bicycle rider using such
bike lanes is minimal. Type IV bikeways are impractical on Sunset Crossing Road or Gold Rush
Drive, so any bicyclists are not protected from motor vehicle traffic. It is the same issue along
Prospectors Road because cars are parked along the sides of the road where a bike lane also exists.
It is not practical to eliminate street parking to accommodate bicycles. Various policies in
Circulation address bicycles. Providing expanded bike lanes is reasonable, but expanding bike
lanes into areas where they are impractical and can result in increased risk and injury to the
bicycle rider should be reconsidered. The concept of bicycle riders switching to motorized
bicycles has DMV licensing issues and additional safety issues and is not an answer to riding a
bicycle up a steep roadway. There are lofty goals in the Circulation policies that are not practical
regardless of whether the wording uses encourage instead of another word. Circulation policy CR-
P-4 cited on page 3.12-33 will have minimal impact on the few pedestrians who walk from
Temple Avenue to Sunset Crossing Road, but it will have a significant impact on vehicular traffic.
The southbound side of Diamond Bar Boulevard to SR-60 is bordered by SR-57 to the right; there
is nothing built on that side of the street. Traffic calming serves no purpose on that side of the
street, but it will impact a bike lane on that side of the street if there are bump-outs placed that
require a bicycle rider to navigate around and move them closer to vehicular traffic.
Respectfully,
Dr. Douglas Barcon
October 29, 2019
Submitted via email to: GLee@DiamondBarCA.Gov
Grace Lee, Senior Planner
City of Diamond Bar
21810 Copley Drive
Diamond Bar California 91765
RE: Comments on the Diamond Bar General Plan Update and EIR
Dear Ms. Lee:
I’m writing on behalf of Hills For Everyone (HFE), to provide comments on the City of
Diamond Bar’s (City) General Plan Update (GPU). HFE is a non-profit organization that strives
to protect, preserve, and restore the environmental resources and natural environs of the Puente-
Chino Hills and surrounding areas for the enjoyment of current and succeeding generations. We
are closely following the City’s GPU as there are natural lands within the city proper and its
sphere of influence.
Public Process Comments
This letter serves as a follow up to our comment letter from July 6, 2018 and focuses on the
policies in the new General Plan. It is our understanding from the Diamond Bar General Plan
Update website (http://www.diamondbargp.com/) that the documents (Environmental Impact
Report, GPU, and Climate Action Plan) were released for a 45 day review period beginning
September 16, 2019 and set to end October 31, 2019.
In our 2018 letter, we specifically requested notification per Public Resources Code §21092.2 to
receive updates about the project. However, it appears that two meetings (listed as Study
Sessions on the website) from September 25 and October 8, 2019 literally changed the
documents we were reviewing during the public comment period. These Study Sessions and
document changes should have occurred prior to the document’s release for public review.
We have accessed the changes published on the website, but must relay our dismay at the public
process. As a governmental entity, as public officials, and as planners you should know better.
2
We do not understand why after release for public review, these documents were then
significantly modified. This is exactly the type of poor public process that confuses the public,
limits engagement, clouds transparency, and leads to distrust toward government. We request
that you officially re-notice and recirculate the entire suite of documents (with the updates from
September and October 2019 included) for a new 45-day review period.
Further, it appears that most of the modifications made essentially eliminate any enforceability of
the General Plan policies. The General Plan needs to be the document that sets the ground rules
for the future of the city. When you change “require” to “encourage,” there is too much
flexibility in the policy. Using the flexible policy language implies interest in the policy, but no
real commitment to it or its enforcement. Flexible policy language does not carry the force of
law.
According to the General Plan Guidelines developed by the comprehensive state planning
agency, the Office of Planning and Research (OPR), “It is better to adopt no policy than to adopt
a policy with no backbone.” (Office of Planning and Research. “General Plan Guidelines.” 15.)
In addition, for a policy to be counted towards “mitigating of a plan’s impacts,” it must be
expressed as mandatory. We urge you to reconsider the edits made in September and October
2019 and require enforceability through stronger policy language.
General Plan Policy Comments
Hills For Everyone provided a suite of topics to consider during the Notice of Preparation of an
Environmental Impact Report for the GPU. These bulleted items relay what we noticed from the
draft GPU.
• We support the focus of infill and preservation of open space (LU-G-2 and -4) and we
support the plan’s attempt to limit impacts to existing residential areas by ensuring there
are compatible adjacent land uses (LU-P-8 and -9).1 LU-P-10 is a good goal (incentivize
affordable housing) and should help (if implemented) meet the new Regional Housing
Needs Assessment numbers for Diamond Bar.
• The inclusion of density and massing in several policies and setting a maximum dwelling
unit/acre for the Transit-Oriented Mixed Use designation is appreciated. This should
help stable residential neighborhoods understand what may or may not be possible to
build next to them.
• Ensuring existing vistas of significant hillside features are preserved will help maintain
Diamond Bar’s character. This sets a good tone for the community too.
• In LU-P-2, we appreciate your inclusion of sensitive species and wildlife corridors.
Further, RC-P-11 2 helps maintain more natural characteristics of wildland areas
especially with the inclusion of wildlife movement linkages, reduced night lighting, and
vegetative buffering. These policies should help the Puente-Chino Hills Wildlife Corridor
lands function and maintain their integrity across multiple counties and multiple cities.
1 The policies have since been modified to a less enforceable policy; we instead support the original language.
2 Ibid.
3
• We appreciate the inclusion of language to not only acknowledge Significant Ecological
Areas, but also to maintain, protect and preserve those biologically significant lands (RC-
G-4 and RC-P-8). 3
Missed Opportunities
We noticed that there were no opportunities for streamlined permitting for land uses like mixed
use. This could help Diamond Bar residents reduce their single occupancy vehicle use and
reduce greenhouse gas emissions. We encourage Diamond Bar to consider adding
streamlined/incentivized permitting for mixed use and transit-oriented projects.
With new legislation regarding Accessory Dwelling Units (ADUs), Diamond Bar missed a
chance to memorialize policies related to ADUs. This should be considered and incorporated so
that it is vertically consistent with the zoning code (§22.42.120).
We again recommend defining what a “major project” is in this document (either by the number
of units, project size, acreage, or amount of grading). For example, this applies to LU-P-4:
“Monitor and evaluate potential impacts of major proposed adjacent, local, and regional
developments...” What exactly triggers this “monitoring and evaluating?”
We recommend, again, setting consistent guidelines that link density, massing, and design. It
would make the document more consistent throughout and set the tone for the City.
Errors in the Document
We again remind you that the area labeled Firestone Scout Reservation on several figures in the
document are not accurate. Firestone Scout Reservation was the former name, but that land has
been owned by the City of Industry since 2001. This naming error should be corrected on
Figures 1-1, 5-1, 6-1, 6-2, 6-3, and 7-9, and Table 5.2 (in two places). Additionally, this land is
not designated parks/open space. We recommend labeling this land as Significant Ecological
Area instead.
Thank you for the opportunity to provide substantive feedback on the GPU. To reiterate, we urge
the City to re-notice and recirculate the documents. Should you have any questions, I can be
reached at 714-996-0502.
Sincerely,
Claire Schlotterbeck
Executive Director
3 Ibid.
1
www.responsiblelanduse.org
October 31, 2019
Submitted via email to: GLee@DiamondBarCA.Gov
Grace Lee, Senior Planner
City of Diamond Bar
21810 Copley Drive
Diamond Bar California 91765
RE: Comments on Draft Environmental Impact Report, Diamond Bar General
Plan and Climate Action Plan 2040
Dear Ms. Lee:
Diamond Bar is a place we all call home, and we very much appreciate the opportunity to
participate in this public process. Responsible Land Use (RLU) has reviewed the
proposed Draft Environmental Impact Report (DEIR), Diamond Bar General Plan
(DBGP), and Climate Action Plan 2040 (CAP). Attached to this letter is a table of our
suggested edits, comments, and questions on the DEIR as well as our general comments,
suggestions and concerns described here.
In general, our members of RLU noted common issues and concerns:
Proposed or Preferred Project was not described in the draft EIR
Reasonable alternatives were not discussed and described, or were erroneously
written off as infeasible and not given further consideration, or
We noted errors and incomplete analysis in coverage of the CEQA criteria.
Alternatives described are infeasible due to assumptions that cannot be fully
analyzed for impacts.
Subsequent release of language changes not reflected in existing DEIR or DBGP.
Significant impacts were not mitigated, and were considered un-mitigatable when
reasonable and feasible alternatives could be proposed.
Proposed or Preferred Project was not described in the draft EIR
The Executive Summary should have a general or high-level description of the Proposed
Project and Community Core Overlay. The Alternatives are described, however, it is
2
difficult to make a comparison to the Proposed Project to the other Alternatives on page
ES-10. The document is making a determination that the Proposed Alternative is the
Environmentally Superior Alternative, but because of the lack of a description it is unclear
why. The EIR should be a stand alone document that does not rely on a description to be
provided separately in the DBGP. In the final EIR, we request that a Project Description
be provided in both the Executive Summary and Section 2.
Reasonable alternatives were not discussed and described
Include a description of the existing Town Center Commercial Area at Diamond Bar Blvd
and Grand with existing EIR mitigation measures and planning as a viable alternative--
which is not the same as the No Project Alternative. Description of the existing town
center utilizing the new EIR mitigation measure requirements and General Plan policies
should also be a reasonable and feasible alternative for this CEQA analysis. In the context
of comparing impacts, keeping the city center at Diamond Bar and Grand also has the
potential to have less environmental impact as compared to your preferred
alternative. For example, Vehicles Miles Traveled would be less, because it is more
centrally located for DB residents in terms of travel to local areas business and therefore
should be described. Also, compared to the Proposed Alternative the existing city center
would not have a Community Core Overlay and would not be an impact to the golf course,
which would make the existing City Center area a potentially environmentally superior to
the Proposed Alternative. This alternative should be described and discussed as to why
it does not meet the City’s purpose and need as described in the EIR.
Significant impacts were not mitigated, and were considered un-mitigatable when
reasonable and feasible alternatives could be proposed
We understand that impacts to Air Quality may be significant and un-mitigatable, however
why does the City not suggest building standards and other reasonable mitigation that
would at least contribute to reductions in air quality impacts? We disagree that there are
no feasible mitigation measures. The City of Diamond Bar should propose mitigation
measures that would reduce emissions even if it would not reduce those impacts to below
significant thresholds. Planning requirements like LEED Building Certification or planning
requirements that would include vehicle charging infrastructure would address these air
quality impacts, as well as GHG emissions, and energy efficiency, and are feasible and
cost effective mitigation. The City of Long Beach has building codes regarding LEED
building policies to reduce energy consumption and GHG emissions as well as EV
Charging Infrastructure. Although, impacts may be less than significant or un-mitigatable,
the city should provide policies or mitigation measures that reasonably reduce its carbon
footprint.
“A significant amount of land in Diamond Bar would need to be converted to public
parkland to reduce the impact to a level that is less than significant. Therefore, the
impact remains significant and unavoidable.”
We also disagree with this statement that the impact is unavoidable or un-
mitagatable. How does the Core Community Overlay address recreation opportunities
sufficiently such that the City can be in alignment with the Quimby Act and meet its ratio
of 5 acres per 1000 residents? According to LU-P-54, the City of Diamond Bar should
3
consider other public uses for public agency lands, such as the county owned Golf
Course. In the event that the County of Los Angeles wanted to make this land more
broadly available to the general public for recreation, there should be a Community Park
Overlay which identifies a use of the golf course to address the shortage of recreation
lands to less than significant. Other options, should also be considered such as greater
mitigation ratios (6 acres: 1000 residents) for new developments, or policies that create
mitigation banks that specifically address and identify city opportunities for future
recreation land development.
Errors and Incomplete Analysis of the CEQA Criteria
We noted that on page 1-4, Diamond Bar only listed a portion of the CEQA Criteria for
the environmental analysis. This is not appropriate, the CEQA analysis does not just
include what was received during the scoping period or an initial analysis. The CEQA
analysis includes the criteria listed in 2019 CEQA Appendix G Checklist of the California
Environmental Quality Act Statutes and Guidelines such as Mineral Resources,
Agriculture, Population and Housing, Public Services, Wildfire and Energy. There should
be a discussion on these topics, are they considered significant or not and why and what
mitigation measures are being proposed to mitigate significant impacts. Additionally,
noise impacts under 3.10 of the Executive Summary Table is incomplete and topics under
3.11 Noise is an error and should be described as Public Services and Recreational
impacts. Agriculture and Mineral Resources are also randomly discussed at the end of
the table. Please revise this table organized based on the CEQA Checklist and address
all the Appendix G items.
DEIR Choice of alternatives are infeasible due to assumptions that cannot be fully
analyzed for impacts
The Golf Course Overlay is a contingency plan which, because of all the unknowns
associated with its implementation cannot be fully analyzed at this time. Therefore, any
attempt to incorporate specific areas of the Golf Course into the current general plan
analysis meets the definition of infeasible in CEQA Guideline § 15364.
Should the Golf Course land ever become available to the city, a specific plan to
implement the overlay will be required, along with a separate EIR. Therefore, we question
why General Plan Alternative 2 was incorporated as an Alternative in the DEIR.
Alternative 2, as shown on Figure 4.2-3, and described on DEIR page 4-5, discusses a
possible town center located in the southern portion of Diamond Bar’s Golf Course. It is
interesting that DEIR author(s) chose this location as one of three alternatives because
this land is currently owned by Los Angeles County.
The ability for this particular location to become a truly viable DEIR alternative is
dependent upon two undisclosed assumptions. The two assumptions are: 1) The county
will eventually close or reduce the size of the Golf Course. 2) The county will not require
mitigation or compensation for the loss of a county property that provides a recreational
service to the local community.
4
There are a number of reasons those assumptions may never come to pass, several of
which are outlined below:
1. It is impossible to predict at this time when and if the County will ever, or might
ever, decide to discontinue Golf Course operations.
2. Two, the County has a general plan with its own parkland requirements to
maintain. Specifically, on page 178, Los Angeles County’s general plan, Chapter
10, states:
“As specified in P/R Policy 3.1, the County standard for the provision of parkland
is 4 acres of local parkland per 1,000 residents of the population in the
unincorporated areas, and 6 acres of regional parkland per 1,000 residents of the
total population of Los Angeles County.”
http://planning.lacounty.gov/assets/upl/project/gp_final-general-plan-ch10.pdf
In order to maintain its own parkland requirements, the County might therefore
reasonably decide to keep the land for itself and develop its own park in place of
the Golf Course. One hundred and seventy some odd acres would make a nice
regional County park.
3. Were the County to ever close the golf course, has there been any precedence set
where the County of Los Angeles deeded lands without adequate compensation
or mitigation for the loss in services? Indeed, for quite a number of years, any hope
the city of Diamond Bar might have had of taking over the golf course property has
been contingent upon the City providing another, fully developed, functioning golf
course facility to the County in exchange. Should the county ever terminate golf
course operation, it is therefore reasonable to fully expect the county to demand
compensation in some as yet undetermined form in exchange for deeding the golf
course property over to the city.
4. It is also possible the County, might decide to use the property for County purposes
other than recreation. As long as the County, being a governmental entity, uses
the property for appropriate governmental purposes, those uses would not fall
under the jurisdiction of Diamond Bar’s general plan. Diamond Bar would have no
say in the County’s land use decision.
Question: given that the conversion of the Golf Course property was a condition of
Alternative 2, why were the specific conditions, costs, environmental impacts, and
required mitigations of obtaining the golf course property omitted from the DEIR?
Question: Please explain, in light of the above evidence, how the City justifies the
inclusion of Alternative 2 as a viable Alternative.
All of the uncertainties, as offered by the evidence above, make fully analyzing the odds,
details, costs and environmental impacts of Diamond Bar acquiring the Golf Course
property “infeasible.” The uncertainty surrounding the acquisition of the property upon
5
which Alternative 2 is based, therefore makes Alternative 2 “infeasible” to even consider
as a viable alternative at this time.
CEQA Guideline §15364,
“Feasible" means capable of being accomplished in a successful manner within a
reasonable period of time, taking into account economic, environmental, legal,
social, and technological factors.
It is important to note that, that the DEIR, on page 3.11-44, also came to a similar
conclusion when it analyzed the potential for increasing parkland acreage the using the
Golf Course property:
“The proposed General Plan includes several policies and land use changes aimed
at increasing available and accessible parkland and open space. However, total
parkland at buildout falls severely short of achieving the parkland ratio of 5.0 acres
per 1,000 residents, and no mitigation is feasible that can make up this gap.
Calculation of the parkland ratio does not include the 134.9 acres of parkland from
the Country Park, which is a private amenity, or the proposed 100 acres of parkland
associated with the Community Core Overlay, given that Los Angeles County has
not ceased operation of the golf course. Conversion of these two areas would
increase the parkland ratio but is not feasible at the time of analysis. A significant
amount of land in Diamond Bar would need to be converted to public parkland to
reduce the impact to a level that is less than significant. Therefore, the impact
remains significant and unavoidable.”
Question: please explain the internal DEIR’s internal discrepancy between the conversion
of the Golf Course property as a condition to Alternative 2 and the statement on page
3.11-44, quoted above, that because the Golf Course has not ceased operation,
conversion of the Golf Course property for additional parkland is not feasible at this time?
Lack of viable alternatives presented makes the DIER “fundamentally and basically
inadequate”
This DEIR presents only three alternatives. One, a no action alternative. Two, an
appropriate alternative placing Diamond Bar’s future “downtown” at the existing Sprouts
location. And three, “Alternative 2,” whose land acquisition issues were discussed above
make it infeasible. Striking Alternative 2, from the DEIR document would leave only two
alternatives.
This is a problem. CEQA Guideline §15126.6 requires that:
An EIR shall describe a range of reasonable alternatives to the project, or to the
location of the project, which would feasibly attain most of the basic objectives of
the project but would avoid or substantially lessen any of the significant effects of
the project, and evaluate the comparative merits of the alternatives.
6
Clearly, one alternative, besides a no action alternative, is not a “reasonable” set of
alternatives. Attempting to analyze the project with only two alternatives, one of which
being infeasible or status quo, makes it impossible for this DEIR to select an alternative
which is environmentally superior.
Question: Given that CEQA Guideline § 15126.6 specifies that an EIR shall describe a
range of reasonable alternatives to the project. How many alternatives does the city
believe an EIR needs in order to be in compliance with this Guideline?
The fact that the city has failed under CEQA guidelines to present a “reasonable” number
of alternatives therefore makes this DEIR subject to CEQA §15088.5 (a)(4). Recirculation
of the DEIR is required when:
The draft EIR was so fundamentally and basically inadequate and conclusory in
nature that meaningful public review and comment were precluded. (Mountain Lion
Coalition v. Fish and Game.)
It is therefore incumbent upon the City to withdraw the current DEIR, replace it with a new
version which includes a “reasonable” number of “feasible” alternatives, and then
recirculate it according to CEQA §15088.5.
Each of the alternatives should avoid or lessen one or more of the significant effects
identified as resulting from the proposed general plan. A reasonable range of alternatives
would typically include different levels of density and compactness, different locations and
types of uses for future development, and different general plan policies. The alternatives
should not all have the same level of impacts. This discussion of alternatives will enable
environmental considerations to influence the ultimate design of the general plan.
General Plan Language Revisions during the public review period
The General Plan Action Committee spent the last three years finding consensus on
general plan policy and goal language with citizens, the city, and themselves. They gave
their final, approved policy language to the city at their final meeting last March. The city
then wrote the draft general plan using that language with minimal changes, and
presented it, along with the DEIR, to the public for a 45-day comment period on Sept 16.
Then, on September 25, in the middle of the comment period, Diamond Bar's City Council
and Planning Commission held a joint "study" session. During that session, city council
members complained the draft general plan language was not "flexible enough." They
ordered the city manager to give them a revised language proposal which removed the
word "require" from general plan policies, and "soften" any policy language which was
“non-flexible.” At the next "study" session on October 8, the city manager offered 40 or
so pages of revised policy changes to the city council.
The actual language revisions were not made public until 72 hours before the subsequent
“study” session on October 8. The revisions, which were part of the second “study”
session’s agenda and staff report, were spread throughout all elements of the general
plan document. All in all, over 170 policies were revised or deleted.
7
One or two policy changes might be considered “insignificant.” However, large numbers
of “insignificant” changes, in this case, over 170, spread throughout the entire general
plan document, easily add up to and meet CEQA guideline §15088.5's definition of
“significant” change.
It is unquestionably the right of the city council to amend general plan language. If the
city planned on having “study” sessions which might include language revisions by the
City Council, those study sessions should have occurred before placing the draft General
Plane and EIR our for public review.
Revising that much policy language in the middle of the 45-day comment period places
the public, Responsible Agencies, Trustee agencies, and state, federal, and local
agencies which may have jurisdiction over the project, in an impossible position for
several reasons:
1, besides being part of the draft general plan language, many of the policies
revised are also found in the DEIR as important mitigation policies. DEIR
comments, submitted before the adopted language revisions, were therefore made
on the basis of mitigation policy language which no longer exists. Those
commenters deserve the right and a reasonable amount of time, specifically
another 45-day comment period, at the very minimum, in which to consider the
import of the language revisions with respect to their comments, and change their
comments as necessary.
2, even for those few who might actually be aware of the general plan language
revisions, and are considering making comments, evaluating mitigation measures
potentially based upon 170 plus revised policies, which are spread across the 691-
page DEIR document, is no trivial task. Especially when one must check every
single general plan policy listed in the DEIR as a mitigation against the “study”
session’s staff report to see which ones have, in fact, been revised. All of the extra
effort required to sort out those language revisions places those individuals and
agencies under an unreasonable burden during the few remaining days of the
comment period. Those individuals and agencies deserve more time to wade
through all of the confusion, specifically, another 45-day comment period to
reconsider their comments.
3, the city has made no effort to inform the public, and agencies who were not
physically present at the second “study” session, that such a large number of
general plan policy revisions were, in fact, made. No where, on the general plan’s
website can one find the news that general plan policy and goal revisions have, in
fact, been adopted. To the interested, but uninformed, web site visitor, the fact of
those adopted language revisions would remain a mystery.
Any reasonable individual would have expected the city to at least notify, according
to California Public Resources Code § 21092.2, the affected agencies and the
general public of the general plan language revisions. Those individuals deserve
the right to make their own determination about whether or not the policy revisions
are indeed, “insignificant.” This is especially so, considering the importance of the
8
document in question: a brand new general plan, the first in over twenty years, with
a projected life span to the year 2040.
4, Adopting those language revisions during what was purported to be a “study”
session in the middle of the comment period was disingenuous. It is true that the
city widely publicized the date and time of the “study” sessions. That said, many
residents, especially those who had spent so much time involved in the general
plan language creation process, took the title of the meetings, “study sessions,” to
mean just that: study. They believed the sessions were intended to “study” the
general plan and DEIR documents, and have the city staff explain the contents of
those documents. No one who saw any of the “study” session announcement
information ever dreamed that the city council would make such drastic language
revisions during those “study sessions.”
The fact that such sweeping general plan policy revisions were adopted, in such an
unexpected manner, with respect to the public’s and affected agencies’ expectations, in
the middle of the public comment period, at a misidentified meeting, those facts, all this
evidence, adds up to and meets the conditions of CEQA Guideline §15088.5
(Recirculation of an EIR Prior to Certification). That article should be, must be invoked
according to CEQA Guideline §15086. The newly adopted language changes must be
incorporated into the draft general plan and DEIR language, with all of the revisions clearly
shown. The general plan, along with the entire DEIR must be then recirculated for another
45-day comment period.
Finally, it should be noted, in this regard, that §15088.5 (e) specifically states: “a decision
not to recirculate an EIR must be supported by substantial evidence in the administrative
record.” The fact that such evidence simply does not exist, should be enough, all by itself,
to require the DEIR, with mitigation policy language revisions clearly marked, to be
recirculated according to the above statues for another 45-day comment period.
General Plan language revisions impact DEIR and CAP mitigations
Impact 3.5-1 Implementation of the Proposed Project would not generate greenhouse
gas emissions, either directly or indirectly, that may have a significant impact on the
environment. (less than significant)
We question the DEIR’s conclusion that the proposed project’s impact on climate change
and greenhouse gases will have a less than a significant impact and does not require
mitigation. The finding is based on the projected reductions that were calculated using
the General Plan policies and CAP policies that were abruptly revised 3 weeks after
publication of the DEIR. The DEIR maintains:
The CAP, once adopted, will serve as a Qualified GHG Reduction Strategy,”
enabling streamlined environmental review of future development projects, in
accordance with CEQA. The future emissions inventory for the City of Diamond
Bar incorporates reductions from State actions, General Plan land use and
circulation systems, and additional General Plan Policies. This analysis shows the
projected GHG emissions in 2030 and in 2040 will be well below the standards
established in the 2017 CARB Scoping Plan. Thus, additional GHG reduction
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actions are not required for the City to have and maintain a Qualified GHG
Reduction Strategy. (3.5-47)
The tables presented in the CAP (3-12 to 3-19) provide quantified reductions in MTCO2e
to justify that the Project will meet regulatory targets. The CAP Table 3-8 which forecast
GHG reductions attributes “the largest reduction from parking policies, followed by
pedestrian improvement and increased connectivity, transportation improvements,
electric vehicle infrastructure, traffic calming, and bikeway system improvements” (CAP
3-18).
However, it is not possible to fully analyze and fully verify the validity of these calculations
in the narrow window of time since the policies were revised by the City Council at the
October 8, 2019 Study Session. Properly evaluating the validity of the revised CAP is
critical since “once adopted, [it] will serve as the Qualified GHG Reduction Strategy,
enabling streamlined environmental review of future development projects in accordance
with CEQA” (3.5-39). How is this still true after the changes in the relevant language?
Will additional mitigation policies be provided to support streamlining the CEQA process?
A significant number of the recently revised general plan policies were cited (to
improve walkability, reduce VMT, promote electric vehicle infrastructure, improve
bikeways and calm traffic) to support this calculation. Here are some examples:
LU-P-17: Promote Require that site designs that create active street
frontages and introduce pedestrian-scaled street networks and street
designs.
LU-P-42: Avoid expanses of surface parking and require encourage the
consolidation and location of parking to the rear or side of buildings where
appropriate.
LU-P-48: Promote Require convenient, attractive, and safe pedestrian, bicycle,
and transit connections both within the Community Core area and between the
Community Core and surrounding neighborhoods and other destinations within
Diamond Bar.
CC-P-57: Improve Promote the pedestrian comfort and safety of crosswalks along
South Brea Canyon Road and South Lemon Avenue.
CR-P-55: Consider the establishment of Incorporate common bicycle
parking requirements for appropriate uses—including multifamily residential
and office—in the Municipal Code.
CR-P-56: Establish requirements to provide Encourage dedicated parking and
charging stations for electric vehicles.
RC-P-20: Require Encourage the implementation of the latest water conservation
technologies into new developments.
RC-P-21: RequireEnsure builders developers to- provide information to
prospective buyers or tenants within the City of Diamond Bar regarding drought-
tolerant planting concepts.
CHS-P-5: As opportunities and resource become available, implement street
design features that facilitate walking and biking in both new and established
areas. Require a minimum standard of these features for all new
developments where appropriate and feasible.
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CHS-P-14: Encourage the development of Develop and incorporate
"destinations"—such as the clusters of commercial uses that draw residents
from the entire community into the Neighborhood Mixed Use, the Transit-
Oriented Mixed Use, and the Town Center focus areas.
CHS-P-15 Establish opportunities for Encourage the establishment of
gathering areas in new neighborhoods.
CHS-P-33 Plan Encourage land uses to reduce vehicle miles traveled
(VMT), prioritizing infill development and incorporating vertical and
horizontal mixed-use development, public transit, and active transportation
facilities where appropriate, recognizing that the transportation sector is the
largest source of GHG emissions in Diamond Bar and in California more
broadly.
CHS-P-35 Use the City's CAP as the platform when considering for outlining
and implementing measures to improve energy conservation and increase
renewable energy use in existing and new development.
As we have noted in a previous document submission to the public record, according to
the General Plan Guidelines developed by the Office of Planning and Research (OPR),
“It is better to adopt no policy than to adopt a policy with no backbone.” (Office of Planning
and Research. “General Plan Guidelines.” 382.)
In addition, for a policy to be counted towards “mitigating of a plan’s impacts,” it must be
expressed as mandatory. (Office of Planning and Research. “General Plan Guidelines.”
382.)
The above changes lead us to specifically ask, what is the likelihood of these policies
being implemented? How do they support the CAP’s calculations that expected targets
would be met? What additional mitigation policies could be provided if the targets are not
met and the impacts become significant? After all, encouragement, consideration, and
promotion are not enforceable forms of policy. They suggest a lack of commitment by
the city to pursue these goals.
We also question the forecasted construction emissions that are “based on an
expectation of a maximum of 10 percent of the total build-out area that could be potentially
developed in any year” (3.5-28). What policies provide the foundation for this
expectation? The DEIR also acknowledges that it is a “conservative estimate” and
“projects would extend for more than one year, and therefore, would increase total project
emissions” (3.5-29). In addition, the report acknowledges that “development anticipated
by the Proposed Project could result in a significant impact, if the per capita emissions
from the 2030 and 2030 (buildout) years exceed the reduction targets identified in the
CAP” (3.5-33). With the revisions to the policy language, how is it certain that the city will
achieve the projected targets? What mitigation measures will be provided since there is
the possibility that impacts could become significant? Why not provide these at this point
rather than assume it will not be necessary?
Moreover, the DEIR assumes “implementation of the Proposed Project’s policies aimed
at resource conservation and VMT reduction would reduce overall GHG emissions
compared to existing conditions and would ensure that the City’s 2030 and 2040 levels
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of GHG emissions would not exceed the respective emission targets” (3.5-35). However,
the same project has “the potential to convert oak woodland to developed areas” (3.5-
38). The report identifies potential areas of development that would disrupt woodland
and that “for every acre of forest removed, an average of 0.85 MTCO2 sequestration is
lost” (3.5-35). Therefore, the DEIR should also calculate the amount of MTCO2
sequestration the loss of mature trees could cost the city. We would also suggest
including the trees in the Golf Course. Doing so would properly evaluate the benefit of
these biological resources to the reduction of GHG and climate change.
The DEIR’s claim that the impact would be less than significant relies on calculations in
the CAP that were based on different policy language. As such, how would other
responsible agencies be able to vet this claim is still true or provide well-informed
comments since they may not be aware of the policy language changes made at the
October 8th Joint Meeting? It would be reasonable to expect that the DEIR and General
Plan/CAP (with its revisions clearly marked with strike-outs) should be recirculated for an
additional comment period.
Please explain how the organizations and agencies outlined in CEQA Guideline § 15086,
who, because no specific announcement was made about the October 8th language
revisions on Diamond Bar’s General Plan website, might reasonably be able to make
informed comments as a result of the general plan language revisions.
Concerns expressed about the haste with which language revisions were made
While we respect concerns about the need for appropriate general plan policy language
flexibility, we believe the language balance has swung too far the other way. We urge that
the Planning Commission and the City Council take the time to carefully consider and
fully understand the value of strategically making the determination of where flexible
language is appropriate, and specific language is needed. The General Plan document
under consideration will guide the city for the next 20 years. We believe it is appropriate,
nay imperative, that we take the time to rethink the hastily revised language, and other
issues mentioned above, and then recirculate the draft General Plan and DEIR for
another 45 days.
Thank you, for the opportunity to participate and comment on the DBGP, EIR and CAP. If
you have any questions or comments on any of the comments provided, we are available
to discuss or provide any clarifications.
Sincerely,
R Lee Paulson
President
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DIAMOND BAR
Draft Environmental Impact Report – Comments
Page DEIR Language Recommended Change Reason/Comments
General Comments
ES-1 Executive Summary
Proposed Project
A general description of the Proposed
Project and the Community Core
Overlay
Review the Chino Hills Final EIR for
examples which describes several
elements:
● Change from the previous
General Plan
● Existing conditions of the city in
terms of development...concerns
and visions.
● Overview of Design Elements
Could discuss limitations such as the
Golf Course and the Community Core
Overlay and why
The Executive Summary should have a general or
high-level description of the Proposed Project and
Community Core Overlay. The Alternatives are
described, however it is difficult to make a
comparison to the Proposed Project to the other
Alternatives on page ES-10.
There needs to be a description of the Proposed
Project as a part of the Executive Summary.
Question: Why was the general or high-level
description of the Proposed Project and
Community Core Overlay omitted from the DEIR?
The document is making a determination that the
Proposed Alternative is the Environmentally
Superior Alternative, but because of the lack of a
description it is unclear why.
Question: How does the city plan to create a clear
description of why the Proposed Alternative is the
Environmentally Superior Alternative?
ES-5 No Project Alternative Include a description of the existing Town
Center at Diamond Bar Blvd and Grand
with existing EIR mitigation measures
and planning as a viable alternative.
Description of the existing town center utilizing the
new EIR requirements should also be a
reasonable and feasible alternative for this CEQA
analysis.
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Responsible Land Use
It may not be a preferred option for the City, but it
is a reasonable and feasible alternative.
Question: Why was the existing town center with
existing EIR mitigation measures and planning
not considered as a viable alternative?
Also, in the context of comparing impacts,
keeping the city center at Diamond Bar and
Grand also has the potential to have less
environmental impact as compared to your
preferred alternative. For example, Vehicles
Miles Traveled would be less, because it is more
centrally located for DB residents in terms of
travel to local areas business and therefore
should be described.
Question: Why was creating a city center at
Diamond Bar Blvd and Grand not considered as a
viable alternative for the DEIR?
Also, compared to the Proposed Alternative there
would not be an impact to the golf course, which
would make the existing City Center area
environmentally superior to the Proposed
Alternative.
ES-7 Areas of Controversy Add insufficient Park and Recreation
Opportunities
Another topic that was discussed in General
Planning Meetings was the lack of recreational
space for residents.
ES-8 As discussed, operational
emissions for the Proposed
Project would exceed
SCAQMD daily emissions
thresholds for CO which
could adversely affect a
We disagree that there are no feasible mitigation
measures. The City of Diamond Bar should
propose mitigation measures that would reduce
emissions even if it would not reduce those
impacts to below significant thresholds. Planning
requirements like LEED Building Certification or
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substantial number of
people. While future
development would be
required to comply with
State, local, and Proposed
Project policies and
regulations, there is no way
to determine the extent to
which these regulations
would be implemented or
their effectiveness, and no
further mitigation is feasible.
planning requirements that would include vehicle
charging infrastructure would address these air
quality impacts and are feasible and cost-effective
mitigation.
Question: We understand that impacts to Air
Quality may be significant and un-mitigatable,
however why does the City not suggest building
standards and other reasonable mitigation that
would at least contribute to reductions in air
quality impacts?
ES-10 Public Facilities
A significant amount of land
in Diamond Bar would need
to be converted to public
parkland to reduce the
impact to a level that is less
than significant. Therefore,
the impact remains
significant and unavoidable
We agree with the DEIR on this. Any discussion
about using Golf Course land for parks is, at this
time, purely speculative. All that can be safely
stated in the DEIR is that should the Golf Course
land become available to the city of Diamond Bar,
allocating a substantial portion of that site for
parkland purposes should be seriously
considered and part of the specific plan and EIR
for the site.
ES-11 Reduced development and
population growth under
Alternative 1 may slightly
reduce impacts of the
Proposed Project; however,
implementation of
Alternative 1 would not be
sufficient to reduce
significant and unavoidable
impacts on air quality,
historic resources, and VMT
to a level that is less than
Alternative 1 does not have a Community Core
Overlay, and has less environmental impacts than
the proposed project. Therefore, it is the
Environmentally Superior Alternative.
Question: why has Alternative 1 been considered
Environmentally inferior, given it has less
environmental impacts than other alternatives?
This also does not take into consideration a third
alternative which could be implementation of the
new environmental requirements for the existing
city center at the intersection of Diamond Bar Blvd
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significant.
and Grand, which would have less impacts for
VMT.
ES-11 Most significantly,
Alternative 1 would not
include the Community
Core overlay, which would
require a master plan to
ensure comprehensive
implementation of reuse of
the Golf Course should the
County of Los Angeles
choose to discontinue its
operation
This statement is unclear.
Question: why is the Preferred or Proposed
Alternative’s Community Core Overlay is not fully
analyzed for this alternative?
The conversion or loss of the County Golf Course
would have to be mitigated for under existing
county requirements. Therefore, the full
connected actions and environmental impacts
cannot be fully described in this analysis if there is
no discussion of the impacts associated with the
replacement for the existing golf course.
The preferred alternative’s Community Core
Overlay would have to undergo a separate CEQA
analysis. It is premature to assume that the
Preferred Alternative is Environmentally Superior
to other Alternatives if the Community Core
Overlay is not fully analyzed, both for the impacts
to potential onsite resources or the associated
mitigation for a golf course relocation.
Question: why is the Preferred Alternative
considered Environmentally Superior to other
Alternatives if the Community Core Overlay is not
fully analyzed, both for the impacts to potential
onsite resources or the associated mitigation for a
golf course relocation?
Question: why is the language at the left even in
the DEIR?
Additionally, the General Plan describes
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Environmental Justice issues particularly
exposure to pollution such as Ozone, Diesel,
Traffic etc. The census tract that includes the
Golf Course is very high for these elements in the
CalEnviroScreen 3.0. Therefore, future
residential development would cause greater
exposure to these future residents and should be
discussed in this document.
Question: Why was greater exposure to pollution
such as Ozone, Diesel, Traffic etc, not discussed
with respect to potential residential development
in this area?
ES-12
Table
ES-3
There needs to be an existing City Center
Alternative (Diamond Bar and Grand) that is
different from the No Project Alternative. This is a
reasonable alternative that has not been
discussed but has the potential for being
environmentally superior.
Question: what the existing City Center at
Diamond Bar and Grand not considered as
another alternative?
ES-12
Table
ES-3
State Scenic Highway Question: Are there no impacts associated with
the eligible State Scenic Highway along Highway
57 in Tonner Canyon?
ES-12
Table
ES-3
Source: Dyett and Bhatia,
2019
I did not find any reference to this source?
Question: Where are the references to this
source?
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ES-55
ES-56
Noise The noise impacts under 3.10 of the Table is
incomplete in that it does not include all the 2019
CEQA Appendix G Checklist Items. Additionally,
the items under 3.11 Noise is an error and should
be described as Public Services and Recreational
impacts. (see Appendix G of 2019 CEQA
Checklist)
ES-57 Transportation The criteria listed in the table only show three
criteria, but the CEQA Checklist Appendix G
includes six criteria. Therefore, this table in
incomplete.
Question: Why aren’t the complete list of criteria
in CEQA Checklist Appendix G included in the
table referenced here?
ES-57 Utilities and Service
Systems
This is also incomplete. There are more criteria in
Appendix G. Globally please review the entire
checklist to complete the EIR analysis.
Question: Why wasn’t the entire list of criteria in
Appendix G listed here?
ES-59 Impacts Not Potentially
Significant
What is this? This table clearly attempts to
identify the CEQA Appendix G Checklist.
However, this section just throws Agriculture,
Mineral Resources at the end randomly.
Please revise this table to organize base on the
CEQA Checklist and address all the Appendix G
items, whether or not there are significant
impacts, and what mitigation measures are being
proposed to mitigate those impacts.
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Why was this table formatted in a way that does
not follow a similar format from the CEQA
Checklist?
1-4 Environmental Issue
Areas
Based on the initial analysis of
environmental setting and baseline
conditions and comments received
during the EIR Scoping Period, the
following issues are analyzed in this
EIR:
This is not appropriate, the CEQA analysis does
not just include what was received during the
scoping period. The CEQA analysis includes the
criteria listed in Appendix G and also includes
Mineral Resources, Agriculture, Population and
Housing, Public Services, etc. There should be a
discussion on these topics, even though they are
either no impacts or they are considered not
significant.
Question: why does the existing analysis only
include those items mentioned in the Scoping
Comments?
Question: Why was a full CEQA analysis of all
criteria not done here?
2-1 Project Description Add pagination to enable comments. This section does not include a description of the
Project. There is also no description of the
project in the Executive Summary. The EIR
should describe the Proposed Project without
having to flip to the General Plan as a reference
and description.
Question: Why was a complete description of the
Project placed in the Executive Summary?
1-6 Mitigated Monitoring and
Reporting Program
We ask for an opportunity to review and comment
on the MMRP. It is important to understand the
city’s expectations of developers and the city’s
responsibility in compliance oversight to ensure
that the Mitigation Measures are complied with.
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Question: To what extent will the public have the
ability to review and comment on the MMRP?
2-1 Project Description This EIR analyzes the proposed
Diamond Bar General Plan 2040
(General Plan) and the proposed
Diamond Bar Climate Action Plan
(CAP), together referred to as the
"Proposed Project." Under California
Government Code Section 65300 et.
seq., cities are required to prepare a
general plan that establishes policies
and standards for future development,
circulation, housing affordability, and
resource protection for the entire
planning area. By law, a general plan
must be an integrated, internally
consistent statement of city policies.
California Government Code Section
65302 requires
that the general plan include the
following seven elements: land use,
circulation, housing, conservation, open
space, noise, and safety. State law
allows cities to include additional (or
optional) elements in general plans as
well. Optional elements included in the
proposed General Plan address
community values related to economic
development, community character,
community health, and sustainability. All
elements of the Proposed Project have
equal weight, and no one element
supersedes another. The Proposed
Project includes six of the seven
elements. The Housing Element, which
is subject to a separate, State-mandated
Question: Why are the laws and regulations being
used here in the Project Description?
This is all being described in Chapter 1. Should
move this statement into Chapter 1 and include a
Project Description.
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eight-year update cycle, was last
updated in 2014, and is not part of the
Proposed Project.
Aesthetics
No Comments.
Noise
There needs to be a map identifying the obvious
noise sensitive receptors: schools, hospitals,
places of worship. This would be feasible to do in
this document, but an analysis for a project
should also be done at the time of a proposal to
the planning commission if there are any sensitive
receptors within a reasonable radius.
Question: where is the map that identifies the
obvious noise sensitive receptors?
3.10-9 Noise Table 3.10-1 Question: At what time of day are these noise
levels assumed?
3.10-30 Noise – Figure 3.10-3 The noise contours should include the
freeways.
The freeways are the loudest and constant source
of noise in the City.
Question: Why are the freeways not included in
this section’s analysis?
3.10-32 PS-P-46 Use the noise and
land use compatibility matrix
(Table 7-1)2 and Projected
Noise Contours map as
criteria to determine the
acceptability of a given
proposed land use,
including the
improvement/construction of
Please ensure that the map also includes the
freeways as well. This Proposed General Plan
will need to take into consideration freeway
improvements and reasonable mitigation such as
sound walls as mitigation.
Question: Will the final EIR ensure the map also
includes the freeways?
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streets, railroads, freeways,
and highways
Question: Will the final EIR take into consideration
freeway improvements and reasonable mitigation
such as sound walls?
3.10-32 PS-P-47 Locate new noise‐
sensitive uses including
schools, hospitals, places of
worship, and homes away
from sources of excessive
noise unless proper
mitigation measures are in
place.
Mitigation Measure: In areas identified
as Noise Sensitive Receptors, such as
schools, hospitals and places of worship
measures to mitigate noise generated
that exceed XX will include measures
such as sound barriers or other methods
to reduce noise generation below
significant levels.
From another EIR:
The following are typical practices for
construction equipment selection (or
preferences) and expected function that
can help reduce noise. Pneumatic
impact tools and equipment used at the
construction site would have intake and
exhaust mufflers recommended by the
manufacturers thereof, to meet relevant
noise limitations. Provide impact noise
producing equipment (i.e., jackhammers
and pavement breaker[s]) with noise
attenuating shields, shrouds or portable
barriers or enclosures, to reduce
operating noise. Line or cover hoppers,
storage bins, and chutes with sound-
deadening material (e.g., apply wood or
rubber liners to metal bin impact
surfaces).
Provide upgraded mufflers, acoustical
lining, or acoustical paneling for other
noisy equipment, including internal
combustion engines. Use alternative
No mitigation is offered for Noise Sensitive
Receptors such as schools and places of worship.
Below on page 3.10-33 you state no mitigation
measures are required.
We have offered additional mitigation measure
language that can reasonably reduce noise
impacts around residents and noise sensitive
receptors.
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procedures of construction and select a
combination of techniques that generate
the least overall noise and vibration.
Use construction equipment
manufactured or modified to reduce
noise and vibration emissions, such as:
Electric instead of diesel-powered
equipment. - Hydraulic tools instead of
pneumatic tools. - Electric saws instead
of air- or gasoline-driven saws.
3.10-13 In extreme cases, the
vibration can cause damage
to buildings.
Question: At what levels are construction vibration
noises impacting structures, and what mitigation
is recommended?
Look at Caltrans 2013 Vibration Guidance Manual
as a reference.
Air Quality
ES-16 CR-P-56: Establish
requirements to provide
Encourage dedicated
parking and charging
stations for Electric Vehicles
We noted that CR-P-56 was modified since the
draft EIR was released for public comment.
Globally we recommend all edits that were
implemented after the draft EIR release be
documented similarly so that the public is aware
of any edits that occurred.
Question: will all edits which were implemented
after the draft EIR release be documented as they
were in the Study Session Staff Report?
We strongly suggest that the language for CR-P-
56 be retained as originally written.
Question: Will the language for CR-P-56 be
reconsidered in light of evidence presented
below?
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The implementation or installation of electrical
infrastructure is reasonable if built into the cost of
construction for new business and parking lots.
However, businesses are reluctant to install
charging station infrastructure after parking lot
completion because of the cost of tearing up the
parking lot and getting separate permits for
installation. Other cities, such as the City of Long
Beach, have implemented policies or ordinances
that required planning for this type of electrical
vehicle infrastructure as part of the permitting
process.
Similarly, the City of Diamond Bar should include
the requirement of LEED Certification or
equivalent to encourage energy efficiency and
reduction of GHG for new construction.
Question: Will the city include the requirement of
LEED Certification or equivalent to encourage
energy efficiency and reduction of GHG for new
construction?
ES-16
3.2-3
Implementation of the
Proposed Project would
expose sensitive receptors
to substantial pollutant
concentrations.
The Community Overlay if implemented to include
high density housing would occur in an area
already deemed an area of high-level pollutant
impacts along the 60 and 57 freeway, please refer
to the CalEnviroScreen 3.0 for this Census Tracs
in this area. Certain elements like diesel
emissions are already at very high levels, with the
City of Industry Census tract 6,037,403,312
already at a Pollution Burden Level of 93%.
Question: Will the final EIR take the above
evidence into consideration, should the
Community Overlay still be seriously considered
in that document?
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3.2-10 California Air Resources Board
(GARBCARB)
Was this supposed to be CARB? Also fix citation
at bottom of table.
3.2-15 As a conservative estimate
of impacts, sensitive
receptors are anticipated to
be located directly adjacent
to new development.
Within this paragraph you mention the types of
sensitive receptors such as schools, long-term
care facilities. These entities do exist, and since
you mention them, it is feasible to identify them.
Particularly public schools. You also have
identified development areas in your planning for
land use changes or future development,
therefore it would be feasible and practical to
identify those sensitive resources in the vicinity of
areas proposed for land use changes (eg. schools
near high density residential).
Question: Will the final EIR document identify and
map sensitive receptors such as schools, long-
term care facilities?
3.2-19 Table 3.2-4 Question: What are you showing here? This table
is incomplete and does not show any data.
3.2-32
3.2-37
The applicable land use
strategies include: planning
for growth around livable
corridors; providing more
options for short
trips/neighborhood mobility
areas; supporting zero
emission vehicles &
expanding vehicle charging
stations; supporting local
sustainability planning.
These are good goals to try and achieve in the
City’s General Plan. The following LU and CRs
do provide the appropriate language: LU-G-4;
LU-G-9; CR-P-33; CR-P-56; RC-P-28; RC-P-
33;RC-P-34; RC-P-35 and others.
However, not all of these General Plan Policies
relate to reduction of air quality impacts, such as
RC-P-19. It is not clear that this is a General Plan
Policy that improves air quality. Or is it possibly a
measure to reduce increased pressure on
Utilities?
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3.2-35 RC-P-30 Ensure that new
development projects are
designed and implemented
to be consistent with the
South Coast Air Quality
Management Plan.
Ensure Require that new development
projects are designed and implemented
to be consistent with the South Coast Air
Quality Management Plan.
The language to ensure puts the onus on the
Planning Commission to check with AQMP.
Requiring that the development project has to
comply with SCAQMD puts the requirement on
the developer and not the Diamond Bar Planning
Commission.
Question: Does the city agree that it is incumbent
upon developers to design and implement project
consistent with the South Coast Air Quality
Management Plan?
Question: Therefore, is it reasonable to require
them to do that?
Question: Will the final EIR change the general
plan language back to its original form? If not,
how will this affect the Planning Commission?
3.2-35 RC-P-33. Consult with
SCAQMD when citing new
facilities with dust, odors, or
Toxic Air Contaminant
(TAC) emissions to avoid
siting those facilities near
sensitive receptors and
avoid siting sensitive
receptors near sources of
air pollution. Require
proposed land uses that
produce TACs to
incorporate setbacks and
design features that reduce
TACs at the source to
minimize potential impacts
from TACs. For new or
modified land uses that
RC-P-33. New development projects are
required to Consult with SCAQMD when
siting new facilities with dust, odors, or
Toxic Air Contaminant (TAC) emissions
to avoid siting those facilities near
sensitive receptors and avoid siting
sensitive receptors near sources of air
pollution. Require proposed land uses
that produce TACs to incorporate
setbacks and design features that
reduce TACs at the source to minimize
potential impacts from TACs. For new or
modified land uses that have the
potential to emit dust, odors, or TACs
that would impact sensitive receptors
require the business owners to notify the
SCAQMD, and residents and
businesses adjacent to the proposed
This language should put the requirement on the
developer to consult and provide that
documentation with the Planning Commission
regarding their consultation with the SCAQMD. It
is not clear who, the City of DB or the developer
must consult with the SCAQMD.
Question: Is it not reasonable to require
developers to consult with SCAQMD when siting
new facilities with dust, odors, or Toxic Air
Contaminant (TAC) emissions to avoid siting
those facilities near sensitive receptors?
Question: Will the EIR final draft then require this?
How?
Also, the sensitive receptors should be identified,
where feasible in this document so that it can be
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Responsible Land Use
have the potential to emit
dust, odors, or TACs that
would impact sensitive
receptors require the
business owners to notify
the SCAQMD, and
residents and businesses
adjacent to the proposed
use prior to business
license or building permit
issuance. (New from
SCAQMD Guidance)
use prior to business license or building
permit issuance. (New from SCAQMD
Guidance)
determined whether the newly provided land use
changes would potentially impact sensitive
receptors such as schools. This language is
pushing that requirement on a case by case basis
without the opportunity to comment here. Also,
this is left to the developer to determine where
there are sensitive receptors. However, it is
feasible to identify existing sensitive receptors in
2020. Also, knowing where the known sensitive
receptors exist will assist the Planning
Commission determine whether notification to the
SCAQMD is required.
3.2-33 Future development in the
City of Diamond Bar that is
consistent with the General
Plan Update would increase
vehicle trips and VMT that
would result in emissions of
ozone precursors and
particulate matter.
Individual projects under the
General Plan Update would
be required to undergo
subsequent environmental
review pursuant to CEQA,
and would be required to
demonstrate compliance
with the AQMP.
We like this statement. This says that every
project needs to go through some sort of
consistency review to ensure that it meets
compliance with AQMP. (AQMD?)
3.2-37 Mitigation Measures
None Required.
Mitigation Measures
With the implementation of the
Proposed General Plan Policies,
impacts are less than significant and
therefore additional mitigation measures
are not None required.
The General Plan Policies are proposed
measures to address impacts and reduce impacts
to Air and GHG emissions.
However, many policies are now worded as
optional rather than mandatory to implement.
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Responsible Land Use
Question: How will the revised policies, which
have been softened, still qualify as mitigations for
impacts to AIR and CHG emissions under CEQA?
3.2-37 Require all off-road diesel
equipment greater than 50
horsepower (hp) used for
this Project to meet USEPA
Tier 4 final off-road
emission standards or
equivalent. Such equipment
shall be outfitted with Best
Available Control
Technology (BACT) devices
including a California Air
Resources Board certified
Level 3 Diesel Particulate
Filter (DPF) or equivalent.
This DPF will reduce diesel
particulate matter and NOX
emissions during
construction activities.
Require all off-road diesel equipment
greater than 50 horsepower (hp) used
for this Project to meet current USEPA
standards, which are currently Tier 4
final off-road emission standards or
equivalent. Such equipment shall be
outfitted with Best Available Control
Technology (BACT) devices including a
California Air Resources Board certified
Level 3 Diesel Particulate Filter (DPF) or
equivalent. This DPF will reduce diesel
particulate matter and NOX emissions
during construction activities.
This mitigation measure should reflect the
changing standards for USEPA from 2020-2040.
Question: How does the city plan to make this
mitigation measure reflect the changing standards
for USEPA from 2020-2040?
3.2-37 MM-AQ-2: Future
development
Require dripless irrigation
and irrigation sensor units
that prevent watering during
rainstorms.
It is not clear how this measure addresses air
quality impacts. Is this meant for reduction of
impacts of water use?
Question: How does this measure address air
quality impacts?
Is this instead meant for reduction of impacts of
water use?
Biological Resources
3.3-1 Table 3.3-1 Formatting issues with the table.
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Figure 3.3-2 Brea Canyon that is referenced on page 3.3-8 as
it leaves the channel in the City of Diamond Bar
and enters the SOI is not identified in figure 3.3-2.
Nor is the channelized portion of the creek.
Question: How will the EIR final draft fix this
oversight?
3.3-12 United States Fish and
Wildlife Service (USFWS)
designated critical habitat
for listed plant or wildlife
species does not occur
within the Planning Area.
The nearest critical habitat
for the Coastal
California gnatcatcher is
located within the Puente-
Chino Hills Wildlife Corridor
in the City of Puente Hills
located to the southwest of
the SOI. Additional critical
habitat for the Coastal
California gnatcatcher is
located within the City of
Walnut but is not adjacent
to the Planning Area
boundaries.
United States Fish and Wildlife Service
(USFWS) designated critical habitat for
listed plant or wildlife species does not
occur within the Planning Area. The
nearest critical habitat for the Coastal
California gnatcatcher is located within
the southwest corner of the SOI and
extends through the Puente-Chino Hills
Wildlife Corridor in the City of Puente
Hills located to the southwest of the SOI.
Additional critical habitat for the Coastal
California gnatcatcher is located within
the City of Walnut and within Chino Hills
State Park but is not adjacent to the
Planning Area
boundaries.
Modified the existing language to be more
descriptive of where known CAGN Critical Habitat
exists. A map would be more helpful.
3.3-45 Promote the use of native
and drought-tolerant
vegetation in landscaping
where practical.
Promote Require the use of native and
drought-tolerant vegetation in
landscaping, site stablization and
restoration where practical to prevent
the spread of invasive plant species into
natural open spaces.
The EIR acknowledges that the spread of
invasive species can take over or outcompete
native vegetation. Therefore, the requirement
should be clear that native seed mixes or
plantings should be used in both landscaping, site
stabilization for SWPPP, and revegetation
purposes.
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Responsible Land Use
Question: How will the EIR final draft clarify this
requirement with the proposed language changes
or the equivalent?
Also, the statement should be clearer to the
developer what is expected of them and why.
Question: Will the EIR final draft clarify what is
expected of the developer in this requirement?
How?
Although the language of where practical is
included for flexibility, native vegetation should be
considered first.
3.3-45 RC-P-9
Require, as part of the
environmental review
process prior to approval of
discretionary development
projects involving parcels
within, adjacent to, or
surrounding a significant
biological resource area, a
biotic resources evaluation
of the site by a qualified
biologist, requiring that time-
specific issues such as the
seasonal cycle of plants and
migration of wildlife are
evaluated. Such evaluation
shall analyze the existing
and potential natural
resources of given site
following at least one site
visit as well as the potential
Require, as part of the environmental
review process, prior to approval of
discretionary development projects
involving parcels within, adjacent to, or
surrounding a significant biological
resource area, a biotic resources
evaluation of the site by a qualified
biologist., Focused plant surveys shall
be conducted at the appropriate time of
year, and local reference populations
checked to ensure detectability of the
target species. requiring that time-
specific issues such as the seasonal
cycle of plants Wildlife shall also be
evaluated by a qualified biologist
through appropriate survey or trapping
techniques necessary to determine
presence. and migration of wildlife are
evaluated. Such evaluation shall
analyze the existing and potential
natural resources of a given site
following at least one site visit as well as
We suggest language that is clear on the steps
needed to be able to adequately identify sensitive
resources and proposal of measures specifically
that would avoid, minimize or mitigate impacts to
species present or potentially present. These
requirements are common on most development
projects in areas impacting potentially sensitive
habitats.
Question: How will the EIR final draft clarify the
language here with the proposed revisions or the
equivalent?
Question: If the final EIR does not plan to clarify
the language here with the proposed revisions or
the equivalent, what are the city’s reasons for not
doing so? That is, by deciding not to clarify the
language, is the city suggesting that adequately
identifying sensitive resources and proposal of
measures specifically that would avoid, minimize
or mitigate impacts to species present or
potentially present not important?
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Responsible Land Use
for significant adverse
impacts on biological
resources, and shall identify
measures to avoid,
minimize, or mitigate any
impacts that would degrade
its healthy function. In
approving any permit based
on the evaluation, the City
shall require implementation
of mitigation measures
supported by the evaluation,
or work with the applicant to
modify the project if
mitigation is determined not
to be adequate to reduce
the impacts to a non-
significant level.
the potential for significant adverse
impacts on biological resources. The
report and shall identify measures to
avoid, minimize, or mitigate any impacts
to species that have been observed or
have the potential of being present on
the site. that would degrade its healthy
function. In approving any permit based
on the evaluation, the City shall require
implementation of mitigation measures
supported by the evaluation, or work
with the applicant to modify the project if
mitigation is determined not to be
adequate to reduce the impacts to a
non-significant level.
3.3-47 MM-BIO-1A
To the extent feasible the
preconstruction surveys
shall be completed when
species are in bloom,
typically between May and
June. Two species, the
white rabbit-tobacco and
San Bernardino aster, are
perennial herbs that grow
up to three feet in height
and can be identified by
their dried stalks and leaves
following their blooming
period.
MM-BIO-1A
To the extent feasible the
preconstruction surveys shall be
completed when species are in bloom,
typically between May and June and
reference populations checked. Two
species, the white rabbit-tobacco and
San Bernardino aster, are perennial
herbs that grow up to three feet in height
and can be identified by their dried
stalks and leaves following their
blooming period.
Suggest adding language on checking reference
populations. This will ensure accuracy of
detecting the target species. This requirement is
not burdensome and often can be determined by
a phone call to a local botanist or checking
websites and providing that documentation.
Question: will the final EIR draft include the
revised language suggestions to ensure accuracy
of detecting the target species?
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Responsible Land Use
3.3-47 MM-BIO-1B
At a minimum, the plan shall
include a description of the
existing conditions of the
project and receiver site(s),
transplanting and/or seed
collection/off-site seeding or
installation methods, a two-
year monitoring program,
any other necessary
monitoring procedures,
plant spacing, and
maintenance requirements.
MM-BIO-1B
At a minimum, the plan shall include a
description of the existing conditions of
the project and receiver site(s),
transplanting and/or seed collection/off-
site seeding or installation methods, an
adaptive two-year monitoring program,
any other necessary monitoring
procedures, plant spacing, and
maintenance requirements. In the event,
that the City of DB determines that
agreed success criteria are not met,
additional remediation may be required
beyond the two-year
maintenance/monitoring period to
ensure mitigation requirements are met.
We believe that there needs to be assurance that
the developer has met obligations. In the two
years of monitoring, there should be adaptive
management of the site to ensure success. If the
mitigation measure conditions are not met in the
established two-year timeframe, it should be the
developer’s obligation to meet those mitigation
measure requirements. If it is not clear to the
developer on what the requirements are, the City
of Diamond Bar risks being the responsible party
for the additional restoration expense, or the
establishment of exotic weed species that could
exacerbate the potential for wildfire.
Question: will the EIR final draft ensure that If the
mitigation measure conditions are not met in the
established two-year time frame, that it will be the
developer’s obligation to meet those mitigation
measure requirements?
Question: if the answer to the above question is
yes, how, specifically, will the EIR final draft
ensure this?
3.3-53 B10-4: Oak Woodlands. In
the event a future project
would result in the loss of
an oak woodland, the
project shall be subject to
the mitigation requirements
set forth in the Los Angeles
County Oak Woodland
Conservation
Management Plan Guide. If
a future project cannot be
redesigned to avoid impacts
on oak woodland, then one
Can this MM BIO-4 align with the City of Diamond
Bar Municipal Code, Chapter 22.38 - Tree
Preservation and Protection? (Page 3.3-38) There
are described restoration ratios that are
inconsistent with BIO-4. We believe the ratios
described are more reasonable biologically.
Question: will this also reference the Oak
Woodland Protection Act 2016?
If the answer to the above question is no, why
not?
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of the following measures
shall be implemented:
• On-site restoration of
a ratio of at least I:I
should be utilized
when circumstances
at the site allow for
long-term
sustainability of the
replacement
plantings, the
potential to
expand/connect to
adjacent oak
woodlands, and/or
the improvement of
degraded oak
woodlands
There are several examples of city documents
that reference oak tree mitigation ratios based on
diameter at breast height and the ratio of
replacement.
We request an ordinance or policy for a no net
policy of trees for the city. A sufficient ratio for
tree replacement based on size or canopy cover
should be established. Please consult references
such as Urban Forestry Program Manual. Or
suggest elements in a MM on elements that need
to be addressed in an ordinance to enable this
MM to mitigate impacts to less than significant.
Although RC-P-10 - development of a mature
native tree ordinance. We should request to
review and comment on the measures in that
ordinance.
3.3-48 MM-BIO-1D
Environmental Awareness
Program
The City shall implement an
Environmental Awareness
Program on its web site
intended to increase
awareness to residents and
city workers of the sensitive
plants, wildlife and
associated habitats that
occur in the preserved open
space areas. The intention
of the program shall be to
encourage active
The City shall implement an
Environmental Awareness Training
Program on its web site intended to
increase awareness to developers,
residents and city workers of the
sensitive plants, wildlife and associated
habitats that occur in the preserved
open space areas. The intention
purpose of the program shall be to
inform developers, city workers and
residents. The program shall address
safety, environmental resource
sensitivities and impacts associated with
the introduction of invasive plant species
as a result of new development. At a
minimum, the Environmental Awareness
This language reads as voluntary.
Question: What requirements will there be for City
Workers or Developers to review the online
program?
We recommend that an Environmental and Safety
Awareness Training be developed that is tailored
and specific to each project based on resource or
safety concerns. It would be the responsibility of
the contractor or developer to ensure that the
workers have taken the awareness training and
provide documentation if requested by the City of
Diamond Bar.
Question, given the need for all individuals at all
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conservation efforts among
the residents and city to
help conserve the habitats
in the preserved open
space. The program shall
address impacts associated
with the introduction of
invasive plant species as a
result of new development.
At a minimum, the
Environmental Awareness
Program shall include the
following components:
Program shall include the following
components:
encourage Provide, on the City website,
information about proactive conservation
efforts among for the residents and city
to help conserve the habitats in the
preserved open space. The program
shall address impacts associated with
the introduction of invasive plant species
as a result of new development. At a
minimum, the Environmental Awareness
Program shall include the following
components:
levels of responsibility to be trained, will the city
make the proposed language revisions?
Question: if the answer to the above question is no,
what are the reasons for that decision?
3.3-48 MM-BIO-1D
For informational purposes,
the City shall provide future
project applicants a
brochure which includes a
list of plant species to avoid
in residential landscaping
near natural areas to
prevent the introduction of
invasive plant species to the
surrounding natural
communities.
For informational purposes, The City
shall provide future project applicants a
brochure which includes a list of
sensitive plant and tree species to avoid
impacting as well as suggested plant
palettes to be used in residential
landscaping near natural areas to
prevent the introduction of invasive plant
species to the surrounding natural
communities
Not only is it important to suggest the types of
plants to avoid, it is also important to identify
sensitive plant and tree species that are protected
by statute or ordinance, and that would require
additional consultation with the city if found onsite.
Question: Does the city agree that it is also
important to identify sensitive plant and tree
species that are protected by statute or
ordinance, and that would require additional
consultation with the city if found onsite?
Question: if the answer to the above question is
yes, will the city agree to the suggested language
revisions or the equivalent?
Question: if the answer to the above question is
no, why not?
MM-BIO-1E
Preconstruction Surveys for
Preconstruction Surveys for Special-
Status Wildlife: Within one (1) week prior
There are circumstances, such as burrowing owl,
where an active nesting burrow can be seasonally
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Special-Status Wildlife:
Within one (1) week prior to
initiating disturbance
activities, clearance surveys
for special-status animal
species shall be performed
by a qualified biologist(s)
within the boundaries of the
future project disturbances.
If any special-status animals
are found on the site, a
qualified biologist(s) with a
CDFG Scientific Collection
Permit shall relocate these
species to suitable habitats
within surrounding open
space areas that would
remain undisturbed, unless
the biologist determines that
such relocation cannot
reasonably be
accomplished at which point
CDFG will be consulted
regarding whether
relocation efforts should be
terminated. Relocation
methods (e.g., trap and
release) and receiver sites
shall be verified and
approved by the CDFG prior
to relocating any animals.
to initiating disturbance activities,
clearance surveys for special-status
animal species shall be performed by a
qualified biologist(s) within the
boundaries of the future project
disturbances. If any special-status
animals are found on the site, a qualified
biologist(s) flag the area for avoidance
and discuss possible seasonal
avoidance measures with the developer.
If avoidance is not feasible, the Project
Biologist, with a CDFG Scientific
Collection Permit shall relocate these
species to suitable habitats within
surrounding open space areas that
would remain undisturbed, unless the
biologist determines that such relocation
cannot reasonably be accomplished at
which point CDFG will be consulted
regarding whether relocation efforts
should be terminated. Relocation
methods (e.g., trap and release) and
receiver sites shall be verified and
approved by the CDFG prior to
relocating any animals.
avoided until a more reasonable time period can
be determined for the species to be relocated and
the burrow collapsed.
Question: will the final EIR include clarifying
language such as that suggested or its equivalent
in the final EIR draft?
If the answer to the above question is no, then why
not?
3.3-50 MM-BIO-1H
Protection of Eagle Nests:
No development or project
activities shall be permitted
within one-half mile of a
Protection of Eagle Nests: No
development or project activities shall be
permitted within one-half mile, if not in
line of site of a proposed activity, one
mile if line of site of a proposed
Question: were the most recent laws and
regulations used for this section? If so, please
specify which ones were used.
We believe the recommendation is to not have
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historically active or active
golden eagle nest unless
the planned activities are
sited in such a way that the
activity has minimal
potential to cause
abandonment of the nesting
site, as determined by a
qualified biologist. 10 In
addition, the eagle nest (if
active) shall be monitored
by a biologist who is highly
familiar with the signs of
eagle distress during the
project development
activities. The monitoring
shall continue until the
monitoring biologist is
confident the nest will not
be disturbed. The
monitoring biologist shall
have the authority to stop
project activities as needed.
activityof a historically active or
determined active golden eagle nest
unless the planned activities are sited in
such a way that the activity has minimal
potential to cause abandonment of the
nesting site, as determined by a
qualified biologist. 10 In addition, the
eagle nest (if active) shall be monitored
by a biologist who is highly familiar with
the signs of eagle distress during the
project development activities. The
monitoring shall continue until the
monitoring biologist is confident the nest
will not be disturbed. The monitoring
biologist shall have the authority to stop
project activities as needed.
activity within a mile of a nest that is determined
active between December-July. A half mile buffer
is used for active nests that are not in line of sight
or have been determined by a biologist (in
consultation with CDFW) will not impact the active
nest.
Eagles are considered fully protected and there
are no take authorizations for this species.
3.3-52 Therefore, impacts to oak
woodlands and other native
woodlands could be
significant and unavoidable
This statement is confusing and is contradictory to
the assumption of Impact 3.3-2 on page 3.3-51
that it is Less than Significant with Mitigation.
Cultural, Hist, Tribal
3.4-25 In the event that human remains or
suspected human remains are identified,
the city shall comply with California law
(Heath and Safety Code § 7050.5; PRC
§§ 5097.94, 5097.98, and 5097.99). The
For Impact 3.4-3 there were no mitigation
measures offered.
Question: why was there no mitigation measure
offered for an inadvertent discovery of human
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area shall be flagged off and all
construction activities within 100 feet (30
meters) of the find shall immediately
cease. The Qualified Archaeologist shall
be immediately notified, and the
Qualified Archaeologist shall examine
the find. If the Qualified Archaeologist
determines that there may be human
remains, they shall immediately contact
the Medical Examiner at the Los
Angeles County Coroner’s office. If the
Medical Examiner believes the remains
are Native American, he/she shall notify
the NAHC within 24 hours. If the
remains are not believed to be Native
American, the appropriate local law
enforcement agency shall be notified.
The NAHC shall immediately notify the
person it believes to be the most likely
descendant (MLD) of the remains, and
the MLD has 48 hours of being granted
access to the site to visit the discovery
and make recommendations to the
landowner or representative for the
respectful treatment or disposition of the
human remains and any associated
grave goods. If the MLD does not make
recommendations within 48 hours of
being granted access to the site, the
remains shall be reinterred in the
location they were discovered and the
area of the property shall be secured
from further disturbance. If there are
disputes between the landowners and
the MLD, the NAHC shall mediate the
dispute and attempt to find a solution. If
the mediation fails to provide measures
remains?
This is generally not anticipated, and although it
may be not considered significant, there should
be a measure in place that a developer and the
city should generally follow. We provided an
example of a MM that addressed inadvertent
discoveries
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acceptable to the landowner, the
landowner or their representative shall
reinter the remains and associated
grave goods and funerary objects in an
area of the property secure from further
disturbance. The location of any reburial
of Native American human remains shall
not be disclosed to the public and shall
not be governed by public disclosure
requirements of the California Public
Records Act, California Government
Code § 6250 et seq., unless otherwise
required by law. The Medical Examiner
shall withhold public disclosure of
information related to such reburial
pursuant to the specific exemption set
forth in California Government Code §
6254(r).
Energy, Climate Change,
GHG
3.5-33 3.5-1 Implementation of
the Proposed Project would
not generate greenhouse
gas emissions, either
directly or indirectly, that
may have a significant
impact on the environment.
(less than significant)
Construction emissions may be more significant
since the report admits it is a “conservative
assumption” based on “an expectation of a
maximum of 10 percent of the total buildout area”
would develop in a year (3.5-28, 3.5-29)
It considers this impact as less than significant
with no mitigation. However, it is based on
assumptions:
3.5: “construction emissions were forecasted
based on an expectation of a maximum of 10
percent of the total build-out area that could be
potentially developed in any year.” but also
acknowledges that “it is likely that some projects
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would extend for more than one year, and
therefore, would increase total project emissions”
and so the “analysis uses a conservative estimate
of total project emissions” (3.5-28- 3.5-29)
It also claims that “policies aimed at resource
conservation and VMT reduction would reduce
overall GHG emissions compared to existing
conditions” (3.5-35).
Question: given that it is intended that “policies
aimed at resource conservation and VMT
reduction would reduce overall GHG emissions
compared to existing conditions,” then why are
the related general plan policies for VMT are not
mandatory?
It also states the “Amount of oak woodland that
would be converted” or replaced are unknown,
the ‘quantification of emissions from conversion
...was not included in the emissions calculations.”
The claim that the impact is less than significant
are based on unreliable assumptions.
(3.5-35)
Question: given that the “Amount of oak woodland
that would be converted” or replaced are
unknown, the ‘quantification of emissions from
conversion ...was not included in the emissions
calculations,” and since the amount of oak
woodland that would be converted or replaced are
unknown, then how can the claim be justified that
the impact is less than significant?
Question: why were the reasons and justifications
for the less than significant claims not included in
the DEIR document?
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The report does have a specific measure: “for
every acre of forest removed, an average of 0.85
MTCO2 sequestration is lost”.
Question: how many acres of forest could be
developed in this plan? The amount of
sequestration that could be lost can be calculated
and included to fully evaluate its impact on
GHG/climate change.
3.5-39 “The CAP, once adopted,
will serve as a Qualified
GHG Reduction Strategy,
enabling streamlined
environmental review of
future development
projects, in accordance with
CEQA
Several policies included in the CAP are no
longer mandatory due to revisions to the General
Plan language in the middle of the comment
period.
Question: How are the assumed reductions in
MTCO2 still valid?
Question: What measures will be added to the
CAP to enable the expected streamlined
environmental review under CEQA?
3.5-28 Significance Criteria Global comment: This document should follow the
2019 CEQA Guidelines. Greenhouse Gas now
only has two criteria under Appendix G. The
other two are now covered under Section VI
Energy.
Question: Why does the EIR not account for the
recent change to the CEQA 2019 Statutes and
Guidelines? How will this be addressed?
3.5-38 CHS-P-44
Promote energy
conservation and retrofitting
of existing buildings through
City of Diamond Bar, should adopt similar policies
as the City of Long Beach regarding LEED
building policies to reduce energy consumption
and GHG emissions. Although, it may be less
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Responsible Land Use
the implementation of the
Green Building Codes.
than significant impacts the city should provide
policies or mitigation measures to further reduce
its carbon footprint and energy efficiency, or
unnecessary consumption of energy resources.
See link below:
http://www.longbeach.gov/globalassets/sustainability/media-
library/documents/urban-living/builidings-and-
neighborhoods/greenbuildingpolicy
Question: Will the city plan to adopt policies as
discussed above which are similar to those
adopted by the city of Long Beach?
CHS-P-41 Support the use
of clean fuel and "climate
friendly" vehicles in order to
reduce energy use, energy
cost, and greenhouse gas
emissions by residents,
businesses, and City
government activities.
We like the policies that the City of Long Beach
described with some goals that they would try and
achieve.
http://www.longbeach.gov/globalassets/sustainability/media-
library/documents/nature-initiatives/action-plan/scap-final
A land use plan element should require that new
commercial, mixed use or transit oriented
developments include the design and installation
of electrical infrastructure to promote the
installation for current or future EV charging
infrastructure.
Current general plan language changes have
made those policies optional. How will the city be
able to achieve the expected reduction in GHG
and meet its emissions targets for automobiles?
Question: Does the city plan to revise those
policies and make them mandatory?
30
Responsible Land Use
Geology, Soils, Seism,
Pale.
No Comments.
Hazards, Haz. Mtrs,
Wildfire
No Comments.
Hydrology and Water Qlty
No Comments.
Land Use/Housing
No Comments.
Noise
Criteria 1
There is no discussion under Criteria 1 in regard
to Sensitive Receptors to noise, such as schools.
Sensitive receptors should be included and
identified under this criteria. And MM should be
suggested that would limit activities during these
hours, or use of noise attenuation measures such
as noise blankets or walls to temporarily reduce
decibel levels in proximity to these sensitive
receptors.
Recreation and Parks
LU-P-53. Ensure adequate
parkland to serve the
recreational needs of
Diamond Bar residents by
providing for a range of park
sizes and amenities,
equitably distributed
throughout the city. Where
necessary to adequately
expand the park system
and/or provide specialized
recreational facilities and
Question: what elements exist in the Parks and
Recreation Master Plan that address the potential
mitigation to increase the availability of parks?
Question: Are there open spaces within the city
that have been identified?
31
Responsible Land Use
programming as identified in
the Parks and Recreation
Master Plan, actively pursue
the acquisition of additional
parkland.
3.11-29 LU-P-54. When a public
agency determines that land
it owns is no longer needed,
advocate for the property to
first be offered to other
agencies, including the City
of Diamond Bar, for public
uses, prior to conversion to
private sector use.
According to LU-P-54, then City of Diamond Bar
should consider other public uses for public
agency lands. Such as the County owned Golf
Course.
Question: How does the Core Community Overlay
address recreation opportunities sufficiently such
that the City can be in alignment with the Quimby
Act and meet its ratio of 5 acres per 1000
residents?
3.11-44 Impact 3.11-3
Implementation of the
Proposed Project would not
include recreational facilities
or require the construction
or expansion of recreational
facilities which might have
an adverse physical effect
on the environment. (Less
than Significant)
This EIR identified several potential new trails:
Tonner Canyon, Crooked Creek etc.
We support the development of trails and access
to views of the open space in the SOI. We would
just like consideration and mitigation measures to
address any potential impacts if and when those
trails are developed.
Question: Why was there no discussion or
consideration of environmental impacts under this
Criteria for the potential new trails?
Transportation
No Comments
Utilities and Service Syst. No Comments.
Alternatives
32
Responsible Land Use
At 4-6 Figure 4.2-2 Alternative 1
In the Transit Oriented Mixed Use Area
it shows both mobile home parks
included. The newly revised area ends
at the east end of the western mobile
home park.
Please revise the map to reflect the currently
correct size.
At 4-6 Figure 4.2-3 Alternative 2 In the Transit Oriented Mixed Use Area
it shows both mobile home parks
included. The newly revised area ends
at the east end of the western mobile
home park.
Please revise the map to reflect the currently
correct size.
Alternatives should also include existing Town
Center at Diamond Bar Blvd and Grand Ave with
the new General Plan and Climate Action Plan. It
is a reasonable alternative that was not
described.
Question: Given that Alternative 2 is not a viable
alternative, why were other alternatives, such as
the location mentioned above considered as
alternatives in the DEIR?
4-13 Implementation of
Alternatives 1 or 2 would
have similar impacts to
biological resources as the
Proposed Project.
The difference between the Proposed Project and
Alternative 1 is a Core Community Overlay, which
if developed, would result in an undetermined
environmental impact to offset the loss of the
existing County Golf Course--as would Alt 2. This
impact, which cannot be adequately quantified at
this time, would in fact have a potentially and
significant environmental impact. Therefore, it is
not clear how the Proposed Alternative is similar
in impact to Alt 1. If the Core Community Overlay
has to be determined at a later time, and may be
determined infeasible due to environmental
considerations, then you have currently only
proposed two alternatives in addition to the No
33
Responsible Land Use
Project Alternative.
Question: Given the reliance of Alternative 2 on
the Community Core Overlay being invoked, and
given the fact that the Golf Course is indeed in
operation, and given the fact that it is “infeasible,”
as defined by CEQA Guideline §15364, at this
time to determine the complete extent of
environmental impacts and mitigations necessary
to have obtained the Golf Course property, why
was Alternative 2 even suggested as a viable
alternative in the DEIR?
Environmentally Superior
Alternative
No Comments.
Impacts not Pot. Signif.
No Comments.
October 31, 2019
Grace S. Lee, Senior Planner
City of Diamond Bar, Planning Division
21810 Copley Drive
Diamond Bar, CA 91765
Transmitted via email: glee@diamondbarca.gov
Re: Draft Environmental Impact Report, City of Diamond Bar General Plan 2040, and
Climate Action Plan, SCH# 2018051066
Dear Ms. Lee:
The California Oaks program of California Wildlife Foundation (CWF/CO) works to
conserve oak ecosystems because of their critical role in sequestering carbon, maintaining
healthy watersheds, providing habitat, and sustaining cultural values.
CWF/CO has reviewed the City of Diamond Bar General Plan 2040, Climate Action
Plan, and the environmental analysis presented in the Draft Environmental Impact Report
(DEIR). Comments pertain to mapping of biological resources, fire hazards, greenhouse
gas and air quality impacts associated with the implementation of the General Plan, and
the city’s tree ordinance. Additionally, CWF/CO offers that the language throughout the
plan about the importance of the natural resources is simply aspirational absent strong
measures combined with enforcement and monitoring.
Mapping data for biological resources: In the letter to the City of Diamond Bar dated
July 3, 2018 CWF/CO stated: “We have also been informed that the habitat mapping
used in the General Plan materials do not accurately represent the city’s oak resources.”
Other letters also addressed this issue, and the letter from Hills For Everyone suggested
that the city utilize more current mapping data. Diamond Bar citizens continue to express
concern that the mapping remains inadequate. CWF/CO understands that Hamilton
Biological, Inc. prepared a biological resources report in February 2019 to correct the
deficiencies. The delivery of the Hamilton report may have been after the comment
period closed. That said, CWF/CO notes the caution in the DEIR on pages 3.3-5 and 3.3-
6, which indicates a need for finer-scale analysis of the mapped vegetation (emphasis
added with boldface text):
As with the native oak and walnut woodlands, there can be considerable
overlap and mixing of shrubland and scrub alliances, which can lead to
misinterpretations of the alliance type when viewed from a distance or in
aerial photography, particularly in the summer when many scrub species
are deciduous. For this reason, the mapping of these alliances and their
mixtures in Figure 3.3-1 should be considered to be subject to site-
specific investigations.
As noted on page 2 of Appendix A of the biological resources report: “Mr. Hamilton
conducted reconnaissance field surveys on January 4 and 8, and February 4 and 8, 2019,
California Wildlife Foundation/California Oaks Comment Letter, October 31, 2019
2
to field-check the mapping and to observe the existing conditions throughout most of
Diamond Bar.”
Fire Hazards: The section, Wildfire Management Strategies, on page 7-16 of the draft
General Plan discusses approaches for mitigating fire risk:
As the State prepares for more such incidents as the wildland-urban
interface (WUI) continues to expand and changes in climate patterns
become more apparent, wildfire risk management at the local level will
become increasingly important. Strategies tend to cluster around two main
approaches: maintaining defensible space around structures, and ensuring
that structures are resistant to fire.
CWF/CO recommends the City of Diamond Bar restrict development in areas designated
by CAL FIRE to pose very high or extreme fire threat as detailed in Figure 7-5 on page 7-
18 and very high fire hazard severity zones as detailed in Figure 7-6 on page 7-19. Such
restrictions would enhance safety and also conserve financial and natural resources. At
the very least, CFW/CO urges the City of Diamond Bar to promulgate citywide fire risk
disclosure requirements for housing developments. Amador County building code
requires the county to make information available to project applicants and real estate
agents on the risks of wildland fire, available levels of fire and emergency response, and
wildland fire prevention methods; and to provide that same information when property
changes hands in areas designated as high and very high fire severity. That information is
posted on the county’s website.
CWF/CO commends the City of Diamond Bar for the language in PS-P-21 presented on
page 3.11-39 of the DEIR, which is protective of natural vegetation. As stated above, a
prohibition of development in these regions would result in further protections. Greater
specificity is needed in the language below to detail how natural ecosystems will be
protected:
Collaborate with the County of Los Angeles Fire Department to ensure that
properties in and adjacent to High or Very High Fire Hazard Severity
Zones as indicated in Figure 7-6 are adequately protected from wildland
fire hazards in a manner that minimizes the destruction of natural
vegetation and ecosystems through inspection and enforcement. Update
Figure 7-6 as new information becomes available from CAL FIRE.
Greenhouse gas impacts: Page 1-6 of the Climate Action Plan recognizes the
greenhouse gas (GHG) impacts of the conversion of oak woodlands and other natural
environments that sequester carbon (boldface text used for emphasis):
California’s oak woodlands act as carbon sinks, storing an estimated 675
million metric tons of carbon dioxide (MTCO2e). Riparian habitats and
wetlands also act as climate sinks and are beneficial to ecological
adaptation to climate change. Destruction of these habitats, both through
land use decisions and the consequences of intensifying climate change,
has the potential to release a significant amount of greenhouse gases.
The Diamond Bar General Plan update includes multiple policies aimed at
preserving open space and riparian habitat to encourage the health of the
City’s biological resources, particularly oak and walnut woodlands, and
California Wildlife Foundation/California Oaks Comment Letter, October 31, 2019
3
applies land use designations that minimize impacts of development on
these resources.
California law requires the assessment of GHG impacts of proposed oak removals, yet
Appendix D does not include such calculations. California Environmental Quality Act §
15364.5 states that “Greenhouse gas” or “greenhouse gases” includes but is not limited to:
carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons,
perfluorocarbons and sulfur hexafluoride. California’s Senate Bill 1383 (2016) designated
methane, black carbon and hydrofluorocarbon short-lived climate pollutants.
Upon the disposal of impacted vegetation, the decomposition of biomass results in CO2 and
CH4 emissions, and the combustion of biomass does in all cases result in CO2, CH4, N2O,
and black carbon.1 CEQA does not differentiate between anthropogenic and biogenic GHG
emissions.2 The following 2009 Natural Resources Agency response to the California
Wastewater Climate Change Group proves the point:
Response 95-1: “Regarding the comment that the Guidelines should distinguish
between anthropogenic and biogenic carbon dioxide emissions, the Natural
Resources Agency notes that SB 97 did not distinguish between the sources of
greenhouse gas emissions. Thus, it would not be appropriate for the Natural
Resources Agency to treat the different categories of emissions differently absent
a legislative intent that the Guidelines do so. Neither AB 32 nor the Air Resources
Board’s Scoping Plan distinguishes between biogenic and anthropogenic sources
of greenhouse gas emissions. On the contrary, the Scoping Plan identifies
methane from, among other sources, organic wastes decomposing in landfills as a
source of emissions that should be controlled. (Scoping Plan, pages 62-63).”
The total biomass weight of the impacted overstory/understory vegetation must be known
and the means of biomass disposal identified to accurately and fully account for natural
land conversion GHG emissions.3 The following questions must be addressed in order for
the environmental documentation to be complete:
• What is the estimated total biomass weight of the impacted overstory and
understory vegetation by 2020, 2030 and 2050?
• Due to the presumed transport of disposed biomass off-site, what are the
estimated CO2, CH4, N2O, and black carbon emissions?
Lastly, on page 8-23 of General Plan, measure CHS-G-11 (boldface text added for
emphasis) is to: “Undertake initiatives to enhance sustainability by reducing the
community’s greenhouse gas (GHG) emissions, protecting natural open spaces which
provide CO2 sequestration, and fostering green development patterns, buildings, sites,
and landscapes.” The City of Diamond Bar needs to add clear language to the General
1 Decomposition: "Anaerobic digestion, chemical process in which organic matter is broken down by
2 "... the combustion of biomass does in all cases result in net additions of CH4 and N2O to the atmosphere,
and therefore emissions of these two greenhouse gases as a result of biomass combustion should be
accounted for in emission inventories under Scope 1" (at p. 11). World Resources Institute/World Business
Council for Sustainable Development (2005).
3 EPA/USDA FS, 2015. Forest Biomass Components: https://cfpub.epa.gov/roe/indicator.cfm?i=86.
California Wildlife Foundation/California Oaks Comment Letter, October 31, 2019
4
Plan to articulate how natural open space protections will be achieved, enforced, and
monitored.
Tree Ordinance: The July 2018 letter by CWF/CO urged “the City of Diamond Bar to
strengthen the tree ordinance by applying it to parcels of one-half acre and smaller, and to
extend individual tree protections to trees smaller than eight inches diameter at breast-
height (DBH).” The DEIR discusses the tree ordinance in the summary of Areas of
Controversy on page ES-7:
Many of the comments addressed impacts to important biological
resources, particularly oak woodlands. Inadequacy of the City of Diamond
Bar’s existing tree ordinance and the Existing Conditions Report led to
community concern over the protection of open space and special-status
species. Anticipated development under the Proposed Project could reduce
existing open space and viable habitat.
Unfortunately, the proposed Resource Conservation policy (RC-P-10) for the impact does
not include an improved tree ordinance:
Require new development to preserve mature native trees including oak
and walnut, and trees of significant cultural or historical value such as
sycamore and arroyo willow, etc., as set forth under the Diamond Bar Tree
Preservation and Protection Ordinance. Review the ordinance periodically
and update it as necessary to reflect current best practices.
Lastly, the DEIR Mitigation Measure Bio-4 presented in table ES-4 on page ES-29 of the
DEIR states that: “In the event a future project would result in the loss of an oak
woodland, the project shall be subject to the mitigation requirements set forth in the Los
Angeles County Oak Woodland Conservation Management Plan Guide.” Restoration
ratios detailed in the table differ (and are weaker in some cases) from those in the City of
Diamond Bar’s tree ordinance section 22.38.130. For example, the county restoration
ratio may be 1:1 in certain circumstances whereas the City of Diamond Bar’s tree
replacement/relocation standards state: “Replacement trees shall be planted at a
minimum 2:1 ratio for residential properties less than 20,000 square feet. Residential
parcels greater than 20,000 square feet and commercial and industrial properties shall
be planted at a minimum 3:1 ratio…” The City of Diamond Bar needs to clarify how the
tree ordinance and mitigation requirements set forth in the Los Angeles County Oak
Woodland Conservation Management Plan Guide are to be reconciled.
Air Quality: Section 5.6 of the General Plan discusses the South Coast Air Basin’s poor
air quality. American Lung Association assigned the grade of F to Los Angeles County’s
air for ozone and particle pollution (24-hour and annual) (see http:// www.lung.org/our-
initiatives/healthy-air/sota/city-rankings/states/california/los-angeles.html).
Resource Conservation-Policy-29 presented on page 5-41 of the General Plan is to:
“Conserve natural open spaces, biological resources, and vegetation, recognizing the role
of these resources in the reduction and mitigation of air pollution impacts, and the
promotion of CO2 sequestration.” However, as stated in the introductory comments,
without specific language and clear protections, there is no reason to believe Diamond
Bar’s natural resource values will be upheld through the implementation of the General
Plan.
California Wildlife Foundation/California Oaks Comment Letter, October 31, 2019
5
Thank you for your consideration of these comments. CWF/CO is available, should
additional information be needed.
Sincerely,
Janet Cobb Angela Moskow
Executive Officer Manager, California Oaks Coalition
1
Diamond Bar – Pomona Valley Sierra Club Task Force
Angeles Chapter
October 31, 2019
TO: Ms. Grace Lee, Senior Planner, City of Diamond Bar [delivered electronically]
CC: City of Diamond Bar, Community Development Director, Mr. Greg Gubman
RE: City of Diamond Bar, General Plan, DEIR Comments
Dear Ms. Lee,
The purpose and goals of the Diamond Bar – Pomona Valley Sierra Club Task Force, Angeles
Chapter, are dedicated to local conservation: to educate environmental literacy to all, especially
the youth; to explore, enjoy and protect local wildlife habitats, to advocate biodiversity, natural
open spaces and sustainable communities. Our group activities and contributions are locally
focused.
We are grateful for the opportunity to comment on the General Plan 2040/DEIR. We think
forward-thinking, community-based partnerships are foundational to guard against error and to
reach for extraordinary levels of quality and economic productivity in conservation planning.
Here are our concerns, which also include a personal point of input:
1. Wildlife Habitat and Circulation: The Resource Conservation element and DEIR fails to
regard or thoroughly explain wildlife circulation throughout the mid and northern part of
the city. Example: my own property which is mapped as oak woodland on DEIR figure
5.2 is partially correct (because the coastal scrub is missing) has been a consistent
“wildlife corridor” these 30 years past (or more?). There is an established “game trail”
where we routinely observe deer families arrive from traversing the native green belt
tracing throughout the Diamond Ridge neighborhood near Pantera Park. The Hamilton
report accurately depicts this region as area #3, in the natural communities map.
Therefore, Hamilton’s approach to mapping natural communities according to their
existence rather than human boundaries is correct. Please explain what scientific basis
the city claims wildlife circulation only happens at the Puente Chino Hills Wildlife
Corridor? Recall, 2013 Diamond Bar city hall sighted a mountain lion, which may have
arrived from Upper Tonner Canyon/Tres Hermanos or Powder Canyon. Here are
pictures of my own property, north face ridgeline, oak/walnut, sage scrub habitat.
2
2. The DEIR city environmental location description is inadequate. There appears
to be no geomorphic, geological or floristic references to where the city of
Diamond Bar is. For example, Dibblee maps indicate the city of Diamond Bar is
located in: Brea Canyon, in the Puente Hills, which are at the tip of the
Peninsular Ranges, in the Southern California Mountains & Valleys Ecoregion.
These terms hold meaningful descriptions by which to assess, soils, native plant
communities, climate patterns. How else can specific ecological features and
conditions be discovered or understood? Will the city of Diamond Bar update
the environmental location of the city in all general plan documents?
3. Geologic Constraints: The DEIR omits describing geologic constraints of the city.
Example: The City’s landscape comprises a system of canyons, streams, floodplains,
ridges, and hillsides. Prominent knolls and ridges reach elevations of 1,300 to 1,400
feet above sea level. Most hillsides contain slopes in excess of 25%. These hillside
areas are underlain by bedrock of the Puente Formation. The rocks of this formation
are folded and dip between 10 and 20 degrees horizontal. Locally, beds of Puente
Formation dip as steep as 45 to 60 degrees. The folded nature of these rocks
combined with the steepness of the terrain makes Diamond Bar one of the most
landslide-prone areas in Southern California. I cannot located descriptions which
help us to understand safety risk, such as landslide potential.
4. Is it meaningful to include the California Deep Landslide Inventory? If not, why
not? Again, isn’t this relevant to safety concerns and mitigation solutions?
3
5. Proposal for new city tree codes including recommendations for oak woodland protection,
walnut woodland protections and productive measures to improve the city urban canopy.
Existing codes are sorely outdated. Based on current science of natural communities and
alliances, per the California Vegetation Manual, Hamilton Biologic analyzed in February 2019, a
new proposed tree code. Attached. A year previous, a red line draft of the previous tree codes
was performed by State Urban Forester, John Melvin’s recommended local urban forester, David
Haas to assist me in analyzing and correcting/improving the city’s existing tree codes. Attached.
I respectfully request the city review this material to achieve updated tree codes to serve the
quality of life in the City of Diamond Bar; and to preserve best practice.
Respectfully,
C. Robin Smith
C. Robin Smith, Chair
References:
Dibblee Maps, Peninsular Ranges, Ecoregion map
Cc: Sierra Club Angeles Chapter, Senior Chapter Director, George Watland
DBPV Sierra Club Task Force, Vice Chair, David Warren
Sierra Club, Angeles Chapter, Conservation Chair, Angelica Gonzales
Sierra Club, San Gabriel Valley Task Force, Chair, Joan Licari
Biological Resources Report
City of Diamond Bar
“This work is dedicated to the City of Diamond Bar, to its
residents --- especially the children.”
Dedicated & Funded by a consortium of Diamond Bar residents and:
Cover Photo by Diamond Bar Resident, Eraina Olson, 2019.
Photos for Resource Protection Recommendations, by Robert Hamilton 2019.
February, 2019
Biological Resources Report
City of Diamond Bar
Prepared By
Hamilton Biological, Inc.
Robert A. Hamilton, President
316 Monrovia Avenue
Long Beach, CA 90803
http://hamiltonbiological.com
February 25, 2019
TABLE OF CONTENTS
TABLE OF CONTENTS .................................................................................. II
INTRODUCTION .......................................................................................... 1
METHODS & TECHNICAL INFORMATION ........................................................... 2
VISIONS, GOALS, OBJECTIVES .......................................................................... 2
HISTORY & LAND USE ................................................................................... 5
SCENIC RESOURCES ....................................................................................... 5
HYDROLOGY/WATERWAYS ........................................................................ 6
DIAMOND BAR WATERSHEDS ......................................................................... 8
FLOODING ................................................................................................... 9
BIOLOGICAL RESOURCES ........................................................................... 9
NATURAL COMMUNITIES ................................................................................ 9
Annual and Perennial Grasslands, Vernal Pools/Seasonal Pools ............ 10
Coastal Sage Scrub, Cactus Scrub .......................................................... 10
Chaparral .............................................................................................. 11
Coast Live Oak Woodland, Savannah ................................................... 11
California Walnut Woodland, Savannah ............................................... 11
Riparian Scrub and Woodlands ............................................................. 12
Human-altered Habitats ........................................................................ 12
NATURAL OPEN SPACE AREAS ....................................................................... 12
RESOURCE PROTECTION RECOMMENDATIONS ................................................. 17
SENSITIVE RESOURCES .................................................................................. 19
Sensitive Natural Communities ............................................................. 20
Special-Status Species ........................................................................... 20
EFFECTS OF DEVELOPMENT ON BIOLOGICAL RESOURCES .................... 29
EDGE/FRAGMENTATION EFFECTS ON WILDLIFE MOVEMENT ............................... 30
Wildlife Movement Issues in the Puente-Chino Hills ............................. 30
NATURAL RESOURCE CONSERVATION POLICIES .................................... 32
GOALS AND POLICIES OF THE OPEN SPACE AND CONSERVATION ELEMENT ........... 32
LITERATURE CITED .................................................................................... 34
III
FIGURES
1: Waterways ............................................................................................. 6
2: Lower San Gabriel River Watershed ....................................................... 7
3a: Natural Open Space Areas, Part 1 ........................................................ 13
3b: Natural Open Space Areas, Part 2 ........................................................ 14
3c: Natural Open Space Areas, Part 3 ........................................................ 15
3d: Natural Open Space Areas, Part 4 ........................................................ 16
TABLES
A: Resource Protection Recommendations ................................................ 17
B: Special Status Species ........................................................................... 22
APPENDICES
A: Methods & Technical Information
1
INTRODUCTION
Hamilton Biological, Inc., was retained by a consortium of Diamond Bar residents to
prepare this biological resources report addressing the conservation and preservation of
sensitive biological resources in the City of Diamond Bar (City) and its Sphere of
Influence. It is intended that the City incorporate the information and analyses in this
report into the next update of its general plan, currently in preparation.
Sections 65302(d) and 65302(e) of the California Government Code states that a city’s
general plan shall include goals and policies for management of open spaces, including
natural lands and recreation areas. The Open Space Element addresses such categories
as preservation of natural resources and managed production of resources. The
Conservation Element addresses protection and maintenance of natural resources,
including soils, water, plants, wildlife, and mineral resources. Recognizing that the
subjects covered under the Open Space Element and Conservation Element
substantially overlap, Appendix 1 to the California Government Code allows these two
elements to be combined in one section of the General Plan.
The Open Space and Conservation Element identifies and describes the irreplaceable
biotic resources that make up the natural environment that people rely upon for
breathable air, clean water, viable populations of native plants and wildlife, and the
natural beauty that pervades and defines Diamond Bar. The Open Space and
Conservation Element guides city decision-makers and the public in their efforts to take
the natural world into account during deliberations over development proposals, as
required to realize the overall vision laid out in the General Plan.
The Open Space and Conservation Element guides the development and
implementation of programs involving conservation of open space, biological
resources, visual resources, and parks and recreation. Approaches for managing
environmental impacts are identified, with particular emphasis on contributing to
achievement of the General Plan’s stated goals, including:
• Create and retain an open space system which will conserve natural resources,
preserve scenic beauty, promote a healthy community atmosphere, provide open
space for outdoor recreation, and protect the public safety.
• Identify limits on the natural resources needed to support urban and rural
development within the City and its Sphere of Influence, and ensure that those
resources are used wisely and not abused.
• Provide a park, recreation and open space system which enhances the livability of
urban and suburban areas by providing parks for residential neighborhoods;
preserving significant natural, scenic, and other open space resources; and meeting
the open space and recreational needs of Diamond Bar residents.
2
Methods & Technical Information
Please refer to Appendix A, which describes the methods for preparing this biological
resources report, as well as providing technical information that underpins the
analyses, conclusions, and policies contained herein.
Visions, Goals, Objectives
The General Plan identifies “a strongly held goal among the residents to maintain and
protect the distinctive physical attributes of Diamond Bar which make it a desirable
place in which to live.” To achieve this overarching goal of safeguarding open spaces
and significant natural features, as well as retaining the City’s distinctive natural
character, the Open Space and Conservation Element focuses on supporting the
following visions, goals and objectives, building upon language contained in the
original 1995 General Plan:
• Vision 1. Retention of the rural/country living community character. There is a
strong, long-held goal among residents to maintain and protect the distinctive,
physical attributes of Diamond Bar which make it a desirable place in which to live,
through a careful balance of housing, businesses and services, public facilities, and
preservation of natural environmental resources.
• Vision 2. Preservation of open space. Significant privately and publicly owned
natural lands that remain in Diamond Bar and its 3,591-acre Sphere of Influence
support numerous rare species and perform important ecological functions. The
preservation of sensitive natural resources contributes to the goal of retaining the
City’s distinctive rustic character and offers unique educational and recreational
opportunities. The County of Los Angeles has identified the Sphere of Influence and
adjacent lands, some of which lie within the City, as Significant Ecological Area
(SEA) 15. SEA 15 is recognized as a major significant ecological asset to the
community. The City will play a proactive role in the preservation of SEA 15 by
assuring that extensive analysis and review precede any changes from its current
uses and possibilities.
o Goal 1. Consistent with the Vision Statement, maintain a mix of land uses
which enhance the quality of life of Diamond Bar residents, providing a
balance of development and preservation of significant open space areas to
assure both economic viability and retention of distinctive natural features of
the community.
§ Objective 1.1 Establish a land use classification system to guide the
public and private use of land within the City and its Sphere of
Influence.
§ Objective 1.2 Preserve and maintain the quality of existing residential
neighborhoods while offering a variety of housing opportunities,
including mixed land uses.
3
§ Objective 1.3 Designate adequate land for retail and service
commercial, professional services, and other revenue generating uses
in sufficient quantity to meet the City’s needs.
§ Objective 1.4 Designate adequate land for educational, cultural,
recreational, and public service activities to meet the needs of
Diamond Bar residents.
§ Objective 1.5 Maintain a feeling of open space within the community
by identifying and preserving an adequate amount of open land.
§ Objective 1.6 Consistent with the Vision Statement, provide flexibility
in the planning of new development as a means of encouraging
superior land use by means such as open space and public amenities.
o Goal 2. Consistent with the Vision Statement, manage land use with respect
to the location, density and intensity, and quality of development. Maintain
consistency with the capabilities of the City and special districts to provide
essential services which achieve sustainable use of environmental and
manmade resources.
§ Objective 2.1 Promote land use patterns and intensities which are
consistent with the Resource Management Element and Circulation
Element.
§ Objective 2.2 Maintain an organized pattern of land use which
minimizes conflicts between adjacent land uses.
§ Objective 2.3 Ensure that future development occurs only when
consistent with the availability and adequacy of public services and
facilities.
o Goal 3. Consistent with the Vision Statement, maintain recognition within
Diamond Bar and the surrounding region as being a community with a well-
planned and aesthetically pleasing physical environment.
§ Objective 3.1 Create visual points of interest as a means of highlighting
community identity.
§ Objective 3.2 Ensure that new development, and intensification of
existing development, yields a pleasant living, working, or shopping
environment, and attracts interest of residents, workers, shoppers, and
visitors as the result of consistent exemplary design.
§ Objective 3.3 Protect the visual quality and character of remaining
natural areas, and ensure that hillside development does not create
unsafe conditions.
4
o Goal 4. Consistent with the Vision Statement, encourage long-term and
regional perspectives in local land use decisions, but not at the expense of
the Quality of Life for Diamond Bar residents.
§ Objective 4.1 Promote and cooperate in efforts to provide reasonable
regional land use and transportation/circulation planning programs.
o Goal 5. Consistent with the Vision Statement, recognize that oak trees, oak
woodlands, and associated habitats have intrinsic aesthetic, environmental,
ecological, wildlife, and economic values; that conservation of oak-
dominated landscapes is important to the health, safety and general welfare
of the citizens of Diamond Bar1; that that the General Plan must contain
adequate policies to protect the oak habitats from unnecessary damage,
removal or destruction; that native oak trees should be planted, where
appropriate, to enhance or restore damaged or degraded oak woodland
habitats and mitigate unavoidable losses.
§ Objective 5.1 Protect and extend the diversity of oak woodlands and
associated habitats (defined as lands on which the majority of the trees
are of the genus Quercus) through site design and land use regulations.
§ Objective 5.2 Reduce in scale, redesign, modify, or if no other
alternative exists, deny any project which cannot sufficiently mitigate
significant adverse impacts to oak woodlands.
§ Objective 5.3 Encourage property owners to establish Open Space
Easements or deed restrictions for areas containing oak woodlands, and
to allow access to enable scientific study.
§ Objective 5.4 Encourage concentration of development on minimum
number of acres (density exemptions) in exchange for maximizing long
term open space.
§ Objective 5.5 As a mitigation option, allow as a condition of
development approval, restoration of any area of oak woodland that is
in a degraded condition, with the magnitude of restoration to be
commensurate with the scope of the project. This may include planting
of oak trees and removal of non-native species, with consideration for
long-term viability, management, and protection, and/or modification
of existing land uses. The object of habitat restoration shall be to
enhance the ecological function of the oak woodland and to restore it
to a condition where it can be self-sustaining through natural
occurrences such as fire, natural hydrological processes, etc.
1 Woodlands are defined as lands with tree cover of at least 10%, and oak woodlands exist where the
majority of trees are of the genus Quercus.
5
History & Land Use
Set within the Puente Hills of southeastern Los Angeles County, the City of Diamond
Bar covers 14.9 square miles. Neighboring cities include Walnut, Pomona, Industry, La
Puente, Rowland Heights, Brea, and Chino Hills. The region now occupied by Diamond
Bar was inhabited by the Kizh people until the mid-eighteenth century, when the
Spaniards settled in the area, establishing Mission San Gabriel in 1771 (City of Diamond
Bar and Diamond Bar Historical Society 2014; Housing element 2014). The land
experienced a series of ownership changes involving various land grants and purchases
(e.g., the Los Nogales Grant; purchases by Luz Linares, Vejar and Palomares, Louis
Phillip, Frederick E. Lewis II, William Bartholome), eventually growing into one of the
largest and respected ranches in southern California and gaining its name. This lasted
until 1956, during which two subsidiaries of Transamerica Corporation (Christiana Oil
Corp and the Capital Oil Company) purchased the area, aiming to make it among the
first and largest master-planned community in Los Angeles County (City of Diamond
and Diamond Bar Historical Society 2014).
Despite initial intentions as a “master-planned” community, uncoordinated patterns of
development through the late twentieth century have introduced areas of incongruence,
such as single- and detached multi-family residential tracts being established alongside
limited commercial and other non-residential sections. Most suburban construction was
already established prior to the city’s incorporation in 1989, and commercial
development has continued expand within the city limit. A few blocks away from the
primary arterials (57 and 60 Freeways) the majority of retail and housing space is
largely concealed by the natural topography, contributing to Diamond Bar’s quiet,
semi-rural character and pleasant atmosphere.
Scenic Resources
Today, Diamond Bar is primarily a hillside residential community, composed of steep
and moderate sloping hills separated by ridges and flat plateaus. Although most of the
land was developed prior to the city’s incorporation, its remaining natural hillsides and
ridgelines provide a picturesque backdrop and strong visual ties to the area’s long
history of ranching. The views from these natural areas comprise powerful and
valuable scenic resources, adding ambiance and aesthetics that give Diamond Bar a
unique and compelling visual identity. In addition, views of trees, rolling hills and the
pine- and often snow-covered peaks of the San Gabriel Mountains are visible in the
distance from the 57 and 60 Freeways.
Planning decisions must recognize the existing aesthetic value of the city’s open space
as well as the external viewsheds of the surrounding region. These include the oak and
walnut wooded ridgelines, unique topography, and natural open spaces at the edges of
the community.
6
HYDROLOGY/WATERWAYS
Diamond Bar lies within of the San Gabriel River watershed, which is the largest
watershed in the drainage system of the San Gabriel Mountains at 441,000 acres (Lower
San Gabriel River Watershed Group 2015). The San Gabriel River is one of seven major
watersheds partly or completely within Los Angeles County. Most of the river lies in
southeastern Los Angeles County, but a portion of this watershed originates in northern
Orange County. The northern portion of the San Gabriel River, where it emerges from
the mountains, has retained some natural features, such as a sandy bottom and native
vegetation. Farther south, however, flood-control and channel stabilization measures
needed to accommodate intensive urbanization led to the river being lined with
concrete (US Army Corps of Engineers 1991; Neal 2011).
Water runs through Diamond Bar via numerous channels, creeks and canyons. A small
part of the northwestern part of the city drains to the San Gabriel River via the San Jose
Creek channel, which follows the route of Valley Boulevard west from Diamond Bar.
Most of Diamond Bar drains south to the San Gabriel River through the Coyote Creek
watershed (see Figure 1).
Figure 1, Waterways. Diamond Bar lies mostly within the watershed of Coyote Creek, but the northwestern
part of the city discharges to the west, through the San Jose Creek channel.
Source: National Hydrology Dataset. http://www.horizon-systems.com/nhdplus/NHDPlusV1download.php
7
Coyote Creek and San Jose Creek drain approximately 165 square miles and 83 square
miles, respectively, of highly urbanized commercial, residential, and industrial zones,
plus limited natural open space areas (Sheng & Wilson 2000, using Horton–Strahler
Stream Order).
In 2013, Diamond Bar joined 12 other cities and the Los Angeles County Flood Control
District to develop a Watershed Monitoring Program (WMP) and Coordinated
Integrated Monitoring Program (CIMP) to address the lower portion of the San Gabriel
River, which includes Reaches 1 and 2 of the San Gabriel River Watershed and portions
of Coyote Creek that originate from jurisdictions within Los Angeles County, including
the City of Diamond Bar. A small portion of Diamond Bar that discharges to the San
Gabriel River via San Jose Creek is also addressed by this CIMP. See Figure 2, below.
Figure 2, Lower San Gabriel River Watershed. Diamond Bar occupies the most northeasterly part of the
Lower San Gabriel River Coordinated Integrated Monitoring Program.
Source: Gateway Water Management Authority. https://gatewaywater.org/services/lsgr/
8
Diamond Bar Watersheds
Diamond Bar is served by four watersheds, all with some channelization/urbanization:
Tonner Canyon Creek, Diamond Bar Creek, Brea Canyon Creek, and San Jose Creek.
Each system supports riparian habitat that provides resources for protected/special-
status species. The following discussions describe each of these four drainage systems.
1. Tonner Canyon
With a watershed of 5,000 acres and very little development, Tonner Canyon ranks
among the most ecologically significant, unchannelized, largely undisturbed drainages
in the Los Angeles area (HFE 2018). Occupying parts of Los Angeles, San Bernardino
and Orange Counties, Tonner Canyon drains the southeastern side of Diamond Bar and
the northwestern side of the City of Chino Hills. The flow rate, controlled by natural
rills, gullies and washes, varies throughout the year. The canyon’s headwaters lie in a
bowl of low hills just south of Diamond Ranch High School. Roughly 1.4 miles
downstream, Grand Avenue cuts across the watershed, and just downstream from that
road crossing lies the small Arnold Reservoir. Below the reservoir’s dam, water flows
southwest through natural open space lands the City of Industry has purchased from
the Boy Scouts of America in recent years. After flowing for approximately a mile
through open, rolling hills, the creek then enters a narrower canyon, with steeper hills
on either side. At that point, the willow-, sycamore-, and oak-dominated riparian
vegetation becomes more developed. The creek flows another six miles south and west
to empty into Brea Creek, located near the 57 Freeway in the Coyote Creek drainage
basin of Orange County.
2. Diamond Bar Creek
Originating in the neighborhoods west of Diamond Ranch High School, Diamond Bar
Creek runs approximately 1.2 miles to the west, through Sycamore Canyon Park, and
then continues west of Golden Springs Road through Diamond Bar Golf Course, and
from there underneath the 57 and 60 Freeways, to a channel east of the freeway that is
tributary to San Jose Creek. The upper segment, from Leyland Drive through the
Sycamore Canyon Park, supports well-developed native sycamore/oak/willow
riparian woodlands. The segment passing through Diamond Bar Golf Course supports
broken, partially native riparian habitat.
3. Brea Canyon Creek
The southwestern part of Diamond Bar, including the “Brea Canyons” neighborhood
east of the 57 Freeway, drains south toward Coyote Creek via Brea Canyon Creek. Most
of this watershed is fully developed within the limits of Diamond Bar, but the
southernmost portion, near the terminus of Castle Rock Road, is a soft-bottomed
perennial creek that supports riparian vegetation.
9
4. San Jose Creek – South Branch/Fork
Located at Diamond Bar’s northwestern edge, the southern branch of San Jose Creek is
a concrete-lined, trapezoidal channel that collects a small portion of urban runoff that is
discharged north of the intersection of Sunset Crossing Road and North Diamond Bar
Blvd. Runoff collected from catch basins drains west toward San Jose Creek in the City
of Industry. At the eastern terminus of Back Lot Lane, in the City of Walnut, lies very
small patch of riparian vegetation consisting of native and exotic trees and shrubs.
Flooding
Flood insurance maps issued by the Federal Emergency Management Agency (FEMA)2,
showing areas that may be subject to flooding in 100-year storm events, indicate that
Diamond Bar is at low risk for major flood events. Only a limited section of the City,
located north of SR-60 (Reed Canyon Channel at Brea Canyon Road and Lycoming
Street) are a slightly elevated flood potential. Surrounding areas at potentially elevated
risk of flooding include locations north of the 57 Freeway (across Baker Parkway) and
an area covering roughly 2,000 acres near the border with Pomona.
An extensive system of concrete-lined drainages, many of which are independent of the
natural streambeds, carries runoff through the City. Areas considered to be at elevated
risk of flooding may require maintenance of drainage channels, which can include
removal of native wetland and riparian vegetation, to maintain the flow of water
through the stormwater system. Diamond Bar’s generally low risk for flooding allows
for native riparian vegetation to be retained in natural streambeds, which can develop
into important habitat for various wildlife species.
BIOLOGICAL RESOURCES
Natural Communities
This section briefly describes the Natural Communities (also known as “plant
communities” or “vegetation types”) that occur in Diamond Bar and its Sphere of
Influence (i.e., Tonner Canyon/Significant Ecological Area 15, located in
unincorporated Los Angeles County south of the city limits). The following discussions
of Natural Communities refer to Natural Open Space Areas in the City and its Sphere of
Influence, which are mapped subsequently (see Figures 3a–3d, starting on page 12).
Please refer also to Appendix A, which describes the State-recommended methods used
to classify Natural Communities for this report.
2 Los Angeles county Flood Zone Definitions, See http://dpw.lacounty.gov/wmd/floodzone/docs/FZDLegend.pdf
10
ANNUAL AND PERENNIAL GRASSLANDS, VERNAL POOLS/SEASONAL POOLS
Natural Open Space Areas: 1, 2, 6, 8, 10, 13, Sphere of Influence
The bottom of Tonner Canyon supports extensive grasslands. Most alliances of the
widespread “California annual grassland” are not identified as Sensitive by CDFW, as
they generally represent areas disturbed over long periods (e.g., by grazing) that no
longer support many native plant species. Among the most prevalent alliances in the
Diamond Bar area is “annual brome grassland.” Dominant species include ripgut
brome (Bromus diandrus), foxtail brome (Bromus madritensis ssp. rubens), wild oats (Avena
fatua), foxtail barley (Hordeum murinum ssp. leporinum), shortpod mustard (Hirschfeldia
incana), black mustard (Brassica nigra), wild radish (Raphanus sativus), Italian thistle
(Carduus pycnocephalus), and tocalote (Centaurea melitensis). Some disturbance-adapted
native forbs, such as common fiddleneck (Amsinckia intermedia) and arroyo lupine
(Lupinus succulentus), may also occur.
Areas of perennial grassland, distinguished by possessing non-trace cover of native
grasses, are identified as Sensitive by CDFW. As examples, the Nassella spp. – Melica
spp. herbaceous alliance is characterized by having at least 2–5 percent cover of native
needlegrass (Nassella spp.) or other native grasses3; and the Bromus carinatus – Elymus
glaucus herbaceous alliance has California brome (Bromus carinatus) characteristically
present, with native plants providing more than 10 percent relative cover.4 It is likely
that vernal pools/seasonal ponds occur in the site’s grasslands, and/or along dirt roads
that pass through other Natural Communities.
Special-status species known to occur in Diamond Bar’s grasslands, or that have
potential to occur there, include Catalina mariposa lily (Calochortus catalinae) small-
flowered microseris (Microseris douglasii ssp. platycarpha), Golden Eagle (Aquila
chrysaetos), and Grasshopper Sparrow (Ammodramus savannarum).
COASTAL SAGE SCRUB, CACTUS SCRUB
Natural Open Space Areas: 1, 4, 7, 8, 10, Sphere of Influence
Hillsides throughout the Puente Hills support stands of coastal sage scrub and cactus
scrub, and this includes the dry, exposed slopes of Diamond Bar. Dominant native
shrubs species in coastal sage scrub include California sagebrush (Artemisia californica),
California buckwheat (Eriogonum fasciculatum), black sage (Salvia mellifera), coyote brush
(Baccharis pilularis), laurel sumac (Malosma laurina), lemonade berry (Rhus integrifolia),
and blue elderberry (Sambucus nigra ssp. caerulea). Within the Study Area, cactus scrub
is dominated by a combination of coastal prickly-pear (Opuntia littoralis) and shrubs
characteristic of coastal sage scrub. The CDFW recognizes most of these scrub/cactus
3 http://vegetation.cnps.org/alliance/536
4 http://vegetation.cnps.org/alliance/499
11
alliances as Sensitive Natural Communities5 in their own right, and they often support
special-status plant and/or wildlife species, such as intermediate mariposa lily
(Calochortus weedii ssp. intermedius), Hubby’s phacelia (Phacelia hubbyi), Coastal
California Gnatcatcher (Polioptila californica californica), and Cactus Wren
(Campylorhynchus brunneicapillus).
CHAPARRAL
Natural Open Space Areas: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, Sphere of Influence
On Diamond Bar’s north- and east-facing slopes, coastal sage scrub is replaced by taller
and denser shrubs and trees with greater requirements for moisture and shade. The
mosaic consists of three main Natural Communities: chaparral, oak woodland, and
walnut woodland. The lowland form of chaparral found in the study area is dominated
by such species as laurel sumac (Malosma laurina), toyon (Heteromeles arbutifolia),
sugarbush (Rhus ovata), chaparral honeysuckle (Lonicera subspicata), and blue elderberry
(Sambucus nigra ssp. caerulea). Special-status species associated potentially found in
chaparral in Diamond Bar include Fish’s milkwort (Polygala cornuta var. fishiae) and the
San Bernardino Ringneck Snake (Diadophis punctatus modestus).
COAST LIVE OAK WOODLAND, SAVANNAH
Natural Open Space Areas: 1, 3, 4, 6, 7, 8, 10, 11, 12, Sphere of Influence
Coast Live Oak Woodland, several associations of which are recognized as Sensitive by
CDFW, is characterized by stands of coast live oak (Quercus agrifolia), and in some areas
Engelmann oak (Quercus engelmannii), often growing together with chaparral and
walnut woodland, on Diamond Bar’s north- and east-facing slopes, as well as in the
bottoms of some drainage courses. Oak savannah, characterized by scattered oaks
growing in grassland, occurs in limited pockets and may be associated with human
disturbance of oak woodlands. Coast live oaks are valuable to a variety of native
wildlife, and are frequently utilized by nesting owls and hawks. Special-status species
that may be found in oak woodlands in the Study Area include the Southern California
Shoulderband Snail (Helminthoglypta tudiculata), Trask’s Shoulderband Snail
(Helminthoglypta traskii), and Long-eared Owl (Asio otus).
CALIFORNIA WALNUT WOODLAND, SAVANNAH
Natural Open Space Areas: 1, 2, 4, 5, 6, 10, 12, Sphere of Influence
This Natural Community, recognized as Sensitive by CDFW, is characterized by stands
of southern California black walnut (Juglans californica) growing in association with
chaparral and coast live oak woodland on Diamond Bar’s north- and east-facing slopes.
Walnut savannah, characterized by scattered walnuts growing in grassland, occurs in
limited pockets and may be associated with human disturbance of walnut woodlands.
5 https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=153609
12
Special-status species that may be found in walnut woodlands and walnut savannah in
Diamond Bar include the species indicated previously for oak woodlands and
chaparral.
RIPARIAN SCRUB AND WOODLANDS
Natural Open Space Areas: 1, 4, 5, 6, 7, 8, 10, 12, 13, Diamond Bar Golf Course, Sphere
of Influence
Various forms of riparian scrub and woodland, nearly all of them recognized as
Sensitive by CDFW, grow along streambeds in Diamond Bar. The dominant vegetation
consists of willows, such as arroyo willow (Salix lasiolepis) and red willow (S. laevigata),
mulefat (Baccharis salicifolia), California sycamore (Platanus racemosa), coast live oak
(Quercus agrifolia), southern California black walnut (Juglans californica), and blue
elderberry (Sambucus nigra ssp. caerulea). Special-status species that may be found in
riparian woodlands in Diamond Bar include the rough hedge-nettle (Stachys rigida var.
rigida), Western Pond Turtle (Emys marmorata), Yellow-breasted Chat (Icteria virens), and
Yellow Warbler (Setophaga petechia).
HUMAN-ALTERED HABITATS
Developed areas, such as turfed/landscaped parks and the Diamond Bar Golf Course,
generally do not support Natural Communities, but these areas may nevertheless play
important ecological roles. For example, the golf course includes large number of
ornamental trees that comprise a non-native woodland that supports a wide variety of
resident and migratory native birds, presumably including nesting raptors, and the
man-made lake provides habitat for migratory and resident ducks and other waterfowl.
Natural Open Space Areas
Figures 3a–3d, starting on the next page, depict 13 areas of extensive (>25 acres)
native/naturalized habitat in Diamond Bar. Also depicted are Diamond Bar Golf
Course and Tonner Canyon/Significant Ecological Area 15, within the city’s Sphere of
Influence. The figures also show potential habitat connections/choke points for wildlife
movement between blocks of natural open space. Figures 3a–3d provide a basis for
generally characterizing the existing ecological conditions within Diamond Bar and its
Sphere of Influence, without accounting for such distinctions as the boundaries of
parklands or private lots.
13
14
15
16
Resource Protection
Recommendations
17
Resource Protection Recommendations
Table A, below, describes and characterizes the ecological characteristics of each
mapped natural open space area at a general level of detail appropriate for a General
Plan. Recommendations are made for the establishment of biological protection
overlays for sensitive habitat areas with high ecological values (e.g., native woodlands
and coastal sage scrub). Note that sensitive natural resources (e.g., special-status
species) and/or important ecological functions (e.g., movement of wildlife) could also
occur outside of the identified areas. More detailed, project-specific surveys would be
required to accurately and adequately describe the ecological resources found in any
open space area.
Table A. Resource Protection Recommendations
Area Acres Description/Main Communities/ Resource Protection Recommendations
1 926
Largest block of natural open space in Diamond Bar, including Pantera Park and northern
part of Tres Hermanos Ranch.
Grassland, Coastal Sage Scrub, Cactus Scrub, Chaparral, Oak Woodland, Walnut Woodland,
Riparian, Human-altered Habitats.
Establish biological protection overlay to conserve (a) large blocks of contiguous natural
habitat for Golden Eagles, Mountain Lions, and other species with large foraging areas, (b)
native scrub habitats with documented populations of California Gnatcatcher and Cactus
Wren, (c) wetland and riparian habitats, and (d) native woodlands; maintain and fortify
habitat connections and wildlife movement opportunities; minimize loss, fragmentation, and
degradation of Natural Communities.
2 64
Only large block of natural open space in Diamond Bar north of 60 Freeway.
Grassland, Coastal Sage Scrub, Chaparral, Coast Live Oak Woodland, Human-altered
Habitats.
Establish biological protection overlay to conserve native scrub habitats and native
woodlands; minimize loss, fragmentation, and degradation of Natural Communities; maintain
and fortify habitat connections and wildlife movement opportunities.
3 72
“Island” of natural open space between Charmingdale Road and Armitos Place.
Coast Live Oak Woodland, Coastal Sage Scrub, Grassland, Human-altered Habitats.
Establish biological protection overlay to conserve native scrub habitats and native
woodlands; minimize loss, fragmentation, and degradation of Natural Communities.
4 438
Includes Summitridge Park and Steep Canyon/Diamond Bar Creek.
Coastal Sage Scrub, Cactus Scrub, Oak Woodland, Riparian, Grassland, Human-altered
Habitats.
Establish biological protection overlay to conserve native scrub habitats with documented
populations of California Gnatcatcher and Cactus Wren, wetland and riparian habitats, and
native woodlands; minimize loss, fragmentation, and degradation of Natural Communities;
maintain and fortify habitat connections and wildlife movement opportunities.
18
Area Acres Description/Main Communities/ Resource Protection Recommendations
5 62
Includes Sycamore Canyon Park/Diamond Bar Creek.
Coastal Sage Scrub, Cactus Scrub, Oak Woodland, Riparian, Grassland, Human-altered
Habitats.
Establish biological protection overlay to conserve native scrub habitats, wetland and riparian
habitats, and native woodlands; minimize loss, fragmentation, and degradation of Natural
Communities; maintain and fortify habitat connections and wildlife movement opportunities.
6 196
Slopes east of City Hall.
Oak Woodland, Walnut Woodland, Oak/Walnut Savannah, Chaparral, Grassland, Coastal
Sage Scrub, Human-altered Habitats, Riparian.
Establish biological protection overlay to conserve native woodlands and savannah;
minimize loss, fragmentation, and degradation of Natural Communities; maintain and fortify
habitat connections and wildlife movement opportunities.
7 154
Includes Larkstone Park.
Coast Live Oak Woodland, Oak Savannah, Coastal Sage Scrub, Chaparral, Riparian,
Grassland, Human-altered Habitats.
Establish biological protection overlay to conserve native woodlands, wetland and riparian
habitats, and native scrub habitats; minimize loss, fragmentation, and degradation of Natural
Communities; maintain and fortify habitat connections and wildlife movement opportunities.
8 231
West of 57 Freeway, south of Pathfinder Road.
Oak Woodland, Oak/Walnut Savannah, Coastal Sage Scrub, Chaparral, Grassland, Human-
altered Habitats.
Establish biological protection overlay to conserve native woodlands and savannah, and
native scrub habitats; minimize loss, fragmentation, and degradation of Natural Communities;
maintain and fortify habitat connections and wildlife movement opportunities.
9 27
Southwestern corner.
Oak Woodland, Chaparral, Grassland.
Establish biological protection overlay to conserve native woodlands; minimize loss,
fragmentation, and degradation of Natural Communities.
10 712
Tonner Canyon tributaries.
Chaparral, Oak Woodland, Walnut Woodland, Oak/Walnut Savannah, Coastal Sage Scrub,
Riparian, Grassland, Human-altered Habitats.
Establish biological protection overlay to conserve native scrub habitats, wetland and riparian
habitats, and native woodlands and savannah; minimize loss, fragmentation, and degradation
of Natural Communities; maintain and fortify habitat connections and wildlife movement
opportunities.
11 39
Southwestern section of The Country; part of Significant Ecological Area 15.
Oak Woodland, Chaparral, Grassland.
Establish biological protection overlay to conserve native woodlands; minimize loss,
fragmentation, and degradation of Natural Communities.
19
Area Acres Description/Main Communities/ Resource Protection Recommendations
12 197
Slopes west of Ridge Line Road.
Oak Woodland, Walnut Woodland, Chaparral, Grassland, Coastal Sage Scrub, Human-
altered Habitats, Riparian.
Establish biological protection overlay to conserve native woodlands, wetland and riparian
habitats, and native scrub habitats; minimize loss, fragmentation, and degradation of Natural
Communities; maintain and fortify habitat connections and wildlife movement opportunities.
13 100
Northeastern part of The Country, adjacent to Tres Hermanos Ranch.
Grassland, Coastal Sage Scrub, Chaparral, Oak Woodland, Riparian, Human-altered
Habitats.
Establish biological protection overlay to conserve (a) large blocks of contiguous natural
habitat for Golden Eagles, Mountain Lions, and other species with large foraging areas, (b)
wetland and riparian habitats, and (c) native woodlands; maintain and fortify habitat
connections and wildlife movement opportunities; minimize loss, fragmentation, and
degradation of Natural Communities.
Diamond
Bar GC 174
Golf course that provides wildlife habitat.
Riparian, Human-altered Habitats (including man-made pond).
Conserve wetland and riparian habitats; maintain and fortify habitat connections and wildlife
movement opportunities.
Sphere of
Influence 3,513
Large and important area of natural open space south of Diamond Bar, including Pantera
Park and northern part of Tres Hermanos Ranch; heart of Significant Ecological Area 15.
Chaparral, Oak Woodland, Walnut Woodland, Oak/Walnut Savannah, Riparian, Grassland,
Coastal Sage Scrub.
Establish biological protection overlay to conserve (a) large blocks of contiguous natural
habitat for Golden Eagles, Mountain Lions, and other species with large foraging areas, (b)
wetland and riparian habitats, (c) native woodlands, and (d) native scrub habitats; minimize
loss, fragmentation, and degradation of Natural Communities.
Sensitive Resources
This biological resources report acknowledges federal, state, and local laws and
ordinances designed to protect and conserve sensitive resources, and identifies City
policies designed to help achieve this objective. For purposes of this report, a sensitive
resource refers to any of the following:
• A Natural Community recognized as having special-status by federal, State, and/or
local governments, and requiring a permit or agreement prior to its disturbance.
• A plant or animal species identified by federal or state governments as endangered,
threatened, rare, protected, sensitive, or a Species of Special Concern.
• A plant or animal that listed by a state or federal agency as a candidate species or
proposed for state or federal listing.
20
SENSITIVE NATURAL COMMUNITIES
The State of California identifies as “Sensitive” the following Natural Communities that
occur in Diamond Bar and its Sphere of Influence:
• Native Grasslands.
• Coastal Sage Scrub.
• Coast Live Oak Woodland (Q. agrifolia/Juglans californica; Q. agrifolia/Q.
berberidifolia/x acutidens; Q. agrifolia/Salvia leucophylla – Artemisia californica; Q.
agrifolia/Salix lasiolepis)6.
• California Walnut Woodland.
• Riparian Scrub and Woodland.
SPECIAL-STATUS SPECIES
In the following Table B, special-status plants and wildlife judged to have potential to
occur within Diamond Bar and its Sphere of Influence are identified and briefly
discussed. The potential for occurrence (low, moderate, high, or known to be present) is
based upon consideration of the species’ habitat requirements and the distribution of
previous verified or highly credible records.
Table B uses the following abbreviations:
• E Endangered (listed by State or Federal governments). “Take” of the
species or disturbance of occupied habitat are prohibited unless
specifically authorized.
• FP Fully Protected by the State of California. These species may not be taken or
possessed at any time, although take may be authorized for necessary
scientific research.
• T Threatened (listed by State or Federal governments). “Take” of the
species or disturbance of occupied habitat are prohibited unless
specifically authorized.
• SSC Species of Special Concern. The California Department of Fish and Wildlife
has designated certain vertebrate species as Species of Special Concern
because declining population levels, limited ranges, and/or continuing
threats have made them vulnerable to extinction. The goal of designating
species as Species of Special Concern is to halt or reverse their decline by
6 In addition to the four coast live oak associations designated as “Sensitive” by CDFW, oak woodlands
within the unincorporated Sphere of Influence are subject to the Los Angeles County Oak Woodlands
Conservation Management Plan pursuant to California Public Resources Code Section 21083 (requires a
county, when acting as a CEQA Lead Agency, to determine whether a proposed project “may result in a
conversion of oak woodlands that will have a significant effect on the environment”).
21
calling attention to their plight and addressing the issues of concern early
enough to secure their long term viability. Not all Species of Special
Concern have declined equally; some species may be just starting to
decline, while others may have already reached the point where they meet
the criteria for listing as a Threatened or Endangered species under the State
and/or Federal Endangered Species Acts.
• CNPS California Native Plant Society. Table B includes plant species
assigned the following ranks by CNPS:
o 1B.1, referring to species CNPS considers to be rare, threatened, or endangered in
California and elsewhere; seriously threatened in California (over 80% of occurrences
threatened / high degree and immediacy of threat).
o 1B.2, referring to species CNPS considers to be rare, threatened, or endangered in
California and elsewhere; moderately threatened in California (20-80% of
occurrences threatened / moderate degree and immediacy of threat).
o 1B.3, referring to species CNPS considers to be rare, threatened, or endangered in
California and elsewhere; not very threatened in California (less than 20% of
occurrences threatened / moderate degree and immediacy of threat).
o 2B.2, referring to species CNPS considers to be rare, threatened, or endangered in
California, but more common elsewhere; moderately threatened in California (20-
80% occurrences threatened / moderate degree and immediacy of threat).
o 4.1, referring to species of limited distribution or infrequent throughout a broader
area in California, whose status should be monitored regularly; moderately
threatened in California (>80% occurrences threatened / moderate degree and
immediacy of threat).
o 4.2, referring to species of limited distribution or infrequent throughout a broader
area in California, whose status should be monitored regularly; moderately
threatened in California (20-80% occurrences threatened / moderate degree and
immediacy of threat).
o 4.3, referring to species of limited distribution or infrequent throughout a broader
area in California, whose status should be monitored regularly; not very threatened in
California (less than 20% of occurrences threatened / low degree and immediacy of
threat or no current threats known).
• NatureServe Element Rankings. In some cases, species have not been granted
special status by state or federal agencies, but they may be recognized as
ecologically sensitive by the California Natural Diversity Database (CNDDB),
which uses a ranking methodology maintained by NatureServe. Species are given a
Global rank (G-rank) that applies to the taxon’s entire distribution, and a State rank
(S-rank) that applies to the taxon’s state distribution. Taxa with rankings of G1, G2,
G3, S1, S2, or S3 may be considered “sensitive” and potentially worthy of special
consideration in resource planning. NatureServe Element Rankings are identified in
Table B only for taxa that have no other federal or state special status.
22
NatureServe Ranks:
o G1, Critically Imperiled, referring to taxa at very high risk of extinction due to extreme
rarity ( often 5 or fewer populations), very steep declines, or other factors.
o G2, Imperiled, referring to taxa at high risk of extinction due to very restricted range, very
few populations (often 20 or fewer), steep declines, or other factors.
o G3, Vulnerable, referring to taxa at moderate risk of extinction due to a restricted range,
relatively few populations (often 80 or fewer), recent and widespread declines, or other
factors.
o S1, Critically Imperiled, referring to taxa critically imperiled in the state because of extreme
rarity (often 5 or fewer populations) or because of factor(s) such as very steep declines
making it especially vulnerable to extirpation from the state.
o S2, Imperiled, referring to taxa imperiled in the state because of rarity due to very restricted
range, very few populations (often 20 or fewer), steep declines, or other factors making it
very vulnerable to extirpation from the state.
o S3, Vulnerable, referring to taxa vulnerable in the state due to a restricted range, relatively
few populations (often 80 or fewer), recent and widespread declines, or other factors
making it vulnerable to extirpation from the state.
Table B. Special-Status Species
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Plants
Astragalus
brauntonii
Braunton’s
Milk-Vetch E — 1B.1
Associated with
calcareous soils.
Unrecorded in the
Puente Hills, but
populations to the
northwest (San
Gabriel Mts.) and
southeast (Chino
Hills, Santa Ana
Mts.).
Moderate potential to
occur in calcareous
substrate, if present.
Detectable only after fire
or other disturbance.
Brodiaea filifolia
Thread-
leaved
Brodiaea
— — 1B.1
Associated with clay
soils. Unrecorded in
the Puente Hills, but
populations to the
north (San Gabriel
Mts.) and southeast
(Santiago Hills).
Low potential to occur in
vernal pools, grasslands, or
openings in coastal sage
scrub.
Calochortus
catalinae
Catalina
Mariposa
Lily
— — 4.2
Widespread in
region, occurring in
clay soils.
Occurs in grasslands or
openings in coastal scrub
or chaparral.
Calochortus
clavatus
var. gracilis
Slender
Mariposa
Lily
— — 1B.2
Unrecorded in the
Puente Hills; popu-
lations to the north-
west (San Gabriel
Mts.).
Low potential to occur in
openings in coastal scrub
or chaparral.
23
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Calochortus
plummerae
Plummer’s
Mariposa
Lily
— — 4.2
Several recent
records of C. weedii
intermedius from
hills south of
Diamond Bar, within
the City’s Sphere of
Influence, may be C.
plummerae hybrids.
Potentially present. Occurs
in openings in coastal sage
scrub or chaparral.
Calochortus weedii
var. intermedius
Intermediate
Mariposa
Lily
— — 1B.2
Several recent
records from hills
south of Diamond
Bar, within the City’s
Sphere of Influence,
identified as C.
weedii intermedius,
but with potential for
hybridization with C.
plummerae.
Occurs in openings in
coastal sage scrub and
chaparral.
Convolvulus
simulans
Small-
flowered
Morning-
glory
— — 4.2
Scattered records
from the region,
including an old
record from 1 mile
east of Brea.
Moderate potential to
occur in grasslands or
openings in coastal sage
scrub. Found in moist
areas.
Dudleya
multicaulis
Many-
stemmed
Dudleya
— — 1B.2
Recorded close to
Diamond Bar, in
west Pomona.
Moderate potential to
occur in openings in
coastal sage scrub or
chaparral.
Horkelia cuneata
ssp. puberula
Mesa
Horkelia — — 1B.1
Unrecorded in the
Puente Hills;
scattered records
across the region.
Low to moderate potential
to occur in sandy openings
in chaparral and oak
woodland.
Juglans
californica
Southern
California
Black
Walnut
— — 4.2
Widespread in
region, including
Diamond Bar and its
Sphere of Influence.
Walnut and oak/walnut
woodlands occur
throughout Diamond Bar
and surrounding hills.
Lepidium
virginicum var.
robinsonii
Robinson’s
Peppergrass — — 4.3
Numerous historical
records from the
county’s interior
foothills, including
the western Puente
Hills; a few recent
records in and near
Diamond Bar.
Occurs in openings in
coastal sage scrub and
chaparral.
Microseris
douglasii ssp.
platycarpha
Small-
flowered
Microseris
— — 4.2
Recorded in
Diamond Bar, south
of Diamond Ranch
High School.
Occurs in grasslands.
Phacelia hubbyi Hubby’s
Phacelia — — 4.2
Several recent
records from
Pomona, Whittier,
and the Santa Ana
Mountain foothills.
High potential to occur in
openings in chaparral or
coastal scrub, such as
along edges of roads and
trails.
24
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Piperia cooperi Cooper’s
Rein-Orchid — — 4.2
Unrecorded in the
Puente Hills;
historical records
from as close as
Claremont and the
Santa Ana River
Canyon.
Low potential to occur in
oak/walnut woodlands,
chaparral, or coastal sage
scrub.
Polygala cornuta
var. fishiae
Fish’s
Milkwort — — 4.3
Recorded in Chino
Hills State Park and
San Gabriel Mts.
Moderate to high potential
to occur in oak/walnut
woodlands or chaparral.
Pseudognaphalium
leucocephalum
White
Rabbit-
tobacco
— — 2B.2
Unrecorded in the
Puente Hills; few
recent records from
surrounding areas.
Low potential to occur in
any sandy wash habitat
that may exist in the study
area.
Quercus
engelmannii
Engelmann
Oak — — 4.2
Recorded in the
Chino/Puente Hills,
La Habra and Yorba
Linda USGS quads.
Moderate potential to
occur in oak/walnut
woodlands.
Senecio aphanactis California
Groundsel — — 2B.2
Historical records
from San Dimas; few
recent records from
surrounding areas.
Moderate potential to
occur in chaparral,
oak/walnut woodlands, or
coastal sage scrub.
Symphyotrichum
defoliatum
San
Bernardino
Aster
— — 1B.2
Historical records
from southeastern
Los Angeles County.
Presumed extirpated.
Very low potential to occur
in moist areas, meadows.
Invertebrates
Bombas crotchii Crotch’s
Bumblebee — S1S2 —
Historical and recent
records scattered
around southern
California.
High potential to occur in
various habitats.
Helminthoglypta
tudiculata
Southern
California
Shoulder-
band Snail
— S1S2 —
Numerous records
from coastal slope of
southern California.
High potential to occur in
various habitats.
Helminthoglypta
traskii traskii
Trasks’s
Shoulder-
band Snail
— G1G2
S1 —
Numerous records
from coastal slope of
southern California.
High potential to occur in
various habitats.
Amphibians
Taricha torosa Coast Range
Newt — SSC —
Not known from
Chino Hills. Nearest
records in San
Gabriel Mts.
Low potential to occur in
and around permanent
water.
Spea hammondii Western
Spadefoot — SSC —
Widespread in region
but limited to
expansive natural
open space areas.
Moderate to high potential
to occur in extensive
grasslands and adjacent
communities with
temporary rain-pools for
breeding.
25
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Reptiles
Emys marmorata Western
Pond Turtle — SSC —
Found in expansive
natural areas, in and
around permanent
water that lacks non-
native turtles or
exotic predators.
Large population known
from Brea Creek; probably
occurs elsewhere in the
study area. Occurs in
creeks and ponds; lays
eggs in nearby uplands.
Phrynosoma
blainvillii
Coast
Horned
Lizard
— SSC —
Found in expansive
natural areas with
sandy openings and
native harvester ants.
High potential to occur in
areas of extensive
chaparral, coastal sage
scrub, and grassland.
Aspidoscelis tigris
stejnegeri
Coastal
Whiptail — SSC —
Widespread in the
region, in various
habitats.
Occurs in chaparral and
coastal sage scrub.
Anniella stebbinsi
So.
California
Legless
Lizard
— SSC —
Local in a variety of
habitats with sandy
soil or deep leaf-
litter.
Moderate potential in
chaparral and
chaparral/oak habitats.
Lampropeltis
zonata pulchra
San Diego
Mountain
Kingsnake
— SSC —
Widespread in the
region, in various
habitats.
Moderate potential to
occur in chaparral, coastal
sage scrub, oak
woodlands, and along
streams.
Arizona elegans
occidentalis
California
Glossy Snake — SSC —
Widespread, but
uncommon, in
habitats with soil
loose enough for
easy burrowing.
Moderate potential to
occur in areas that have
extensive patches of loose
soil.
Salvadora
hexalepis
virgultea
Coast Patch-
nosed Snake — SSC —
Widespread in the
region, in brushy and
rocky habitats.
Moderate potential to
occur in chaparral, coastal
sage scrub, oak
woodlands, and along
streams.
Thamnophis
hammondii
Two-striped
Garter Snake — SSC —
Widespread in the
region, in and
around perennial
water.
Moderate potential to
occur near perennial
water.
Crotalus ruber
Red
Diamond
Rattlesnake
— SSC — Widespread in the
region.
Occurs in cactus scrub,
coastal sage scrub, and
chaparral.
Birds
Geococcyx
californianus
Greater
Roadrunner — — —
Widespread in
expansive natural
areas with shrub
cover. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Resident in coastal sage
scrub and chaparral
habitats.
26
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Aquila
chrysaetos Golden Eagle — FP —
Formerly widespread
in many habitats, but
now limited to
expansive natural
areas. Nests on cliffs
and in tall trees away
from settlements.
Regularly observed
foraging in northeastern
part of study area. Pair
appears to be resident in
the Chino Hills/Diamond
Bar area; nesting status
unknown. Additional birds
may occur during
migration/winter.
Circus hudsonius Northern
Harrier — SSC —
Nests on the ground
in expansive open
space areas; more
widespread during
migration and winter.
Winters in open grassland
habitats. Moderate
potential to nest in the
northeastern and southern
parts of study area.
Elanus leucurus White-tailed
Kite — FP —
Nests in trees within
expansive open
space areas; more
widespread during
migration and winter.
Forages in
rangelands and
marshy areas.
One or more observed
near Diamond Ranch High
School on unspecified date
(Sage Environmental
Group 2012). High
potential to occur in
migration and winter,
especially in northeastern
and southern parts of study
area. Moderate potential to
nest in the northeastern or
southeastern parts of the
study area.
Buteo regalis Ferruginous
Hawk — — —
Winters in expansive
rangelands and
agricultural areas in
the region. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Moderate to high potential
to occur in migration and
winter, in northeastern and
southern parts of study
area. Does not nest in the
region.
Athene cunicularia Burrowing
Owl — SSC —
Nesting population
west of the deserts
nearly extirpated.
Winters rarely and
locally, usually in
expansive open
space areas.
Likely extirpated as nesting
species in Diamond Bar
area. Moderate potential to
occur in migration and
winter, especially in
northeastern and southern
parts of study area.
Asio otus Long-eared
Owl — SSC —
Resident in oak
woodlands, typically
>1 km from urban
areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Low to moderate potential
to occur in woodlands in
southeastern part of study
area.
Asio flammeus Short-eared
Owl — SSC —
Winters in expansive
open areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Low potential to occur in
migration and winter, in
northeastern and southern
parts of study area. Does
not nest in the region.
27
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Falco mexicanus Prairie
Falcon — — —
Winters in expansive
rangelands and
agricultural areas in
the region. Nests on
remote cliffs.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
Low to moderate potential
to occur in migration and
winter, in northeastern and
southern parts of study
area. Unlikely to nest due
to lack of remote cliffs.
Empidonax traillii Willow
Flycatcher E E —
Does not nest in the
local area.
Uncommon during
migration.
No potential for nesting.
Species occurs in the study
area regularly during
migration periods.
Lanius
ludovicianus
Loggerhead
Shrike — SSC —
Nests rarely in the
region, in expansive
open space areas;
more widespread in
migration and winter.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
High potential to occur in
migration and winter,
especially in northeastern
and southern parts of study
area. Low to moderate
potential to nest in the
study area.
Vireo bellii bellii Least Bell’s
Vireo E E —
Nests uncommonly
in riparian scrub and
woodlands, often in
mulefat (Baccharis
salicifolia) or willow
(Salix spp.).
Moderate potential to nest
in riparian habitats,
especially in Tonner
Canyon.
Eremophila
alpestris Horned Lark — — —
Nests and winters in
expansive rangelands
and agricultural areas
in the region.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
Low potential to occur in
the northeastern and
southern parts of study
area.
Campylorhynchus
brunneicapillus
Cactus
Wren,
coastal
populations
— SSC —
Rare and declining
resident of cactus
scrub habitat.
Resident in well-developed
cactus scrub, including
Summitridge Park, Pantera
Park, Steep Canyon, and
hills south of Diamond
Ranch High School.
Polioptila
californica
californica
Coastal
California
Gnatcatcher
T SSC —
Uncommon resident
in coastal sage scrub
habitat, favoring
shallow slopes and
elevations below
1,500 feet.
Resident in coastal sage
scrub and cactus scrub,
including Summitridge
Park, Pantera Park, Steep
Canyon, and hills south of
Diamond Ranch High
School.
Sialia currucoides Mountain
Bluebird — — —
Winters in expansive
open areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
High potential to occur, at
least during some winters,
in northeastern and
southern parts of study
area. Does not nest in the
region.
Icteria virens
Yellow-
breasted
Chat
— SSC —
Nests uncommonly
in riparian scrub and
woodlands.
High potential to nest in
riparian habitats, especially
in Tonner Canyon.
28
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Setophaga
petechia
Yellow
Warbler — SSC — Nests in riparian
woodlands.
High potential to nest in
riparian habitats, especially
in Tonner Canyon.
Pooecetes
gramineus
Vesper
Sparrow — — —
Winters in expansive
open areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
High potential to occur in
northeastern and southern
parts of study area. Does
not nest in the region.
Ammodramus
savannarum
Grasshopper
Sparrow — SSC —
Nests in expansive
grasslands and
rangelands.
High potential to nest in
open grassland and
rangeland habitat. Several
eBird records from the
Diamond Bar area in the
1990s; lack of recent
records probably reflects
lack of survey effort.
Sturnella neglecta Western
Meadowlark — — —
Nests rarely in the
region, in expansive
open space areas;
widespread in
migration and winter.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
Occurs in open areas
throughout the study area;
moderate potential to nest
in the northeastern or
southern parts of study
area.
Agelaius tricolor Tricolored
Blackbird — SSC —
Nests in wetlands
adjacent to
expansive grasslands
and rangelands
required for foraging.
Winters in
rangelands and
parks.
Low potential to nest in the
study area. Moderate
potential to forage in open
grassland and rangeland
habitat during the nesting
season. Recorded in winter
at parks in the study area.
Mammals
Antrozous
pallidus Pallid Bat None SSC —
Widespread in
chaparral and similar
habitats, foraging on
the ground and in
vegetation. Roosts in
rock crevices and
under tree bark.
Maternal roosts
active between
March and August.
High potential; chaparral
and scrub on the site are
potentially suitable for
foraging and oaks provide
potential roosting sites
under exfoliating bark and
in cavities.
Eumops perotis
californicus
Western
Mastiff Bat None SSC —
Roosts in cliff
crevices and in
buildings.
Low potential; the species
may fly over the site
occasionally while
foraging, but suitable cliff
roosting habitat probably
absent.
Lasiurus blossevillii Western
Red Bat None SSC —
Roosts in foliage of
many types of tree;
feeds over a wide
variety of habitats.
Moderate potential to roost
in oak woodlands or
landscape trees; high
potential to forage over
undeveloped areas.
29
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Lasiurus xanthinus Western
Yellow Bat None SSC —
Roosts primarily or
entirely in palms;
often forages over
water.
Moderate potential to roost
in palm trees and to forage
over water features.
Chaetodipus fallax
fallax
NW San
Diego Pocket
Mouse
None SSC —
Scrub habitats with
sandy or gravelly
soils.
High potential to occur in
cactus scrub and coastal
sage scrub habitats with
sutiable soils.
Neotoma lepida
intermedia
San Diego
Desert
Woodrat
None SSC —
Widespread in scrub
habitats, especially
those with cactus.
High potential to occur in
cactus-containing scrub.
Lepus californicus
bennettii
San Diego
Black-tailed
Jackrabbit
None SSC —
Occurs in various
open habitats,
usually in expansive
open space areas.
Low potential to occur in
the northeastern and
southern parts of the study
area.
Taxidea taxus American
Badger None SSC
Occurs in various
habitats, usually in
expansive open
space areas.
Moderate to high potential
to occur in the
northeastern and southern
parts of the study area.
EFFECTS OF DEVELOPMENT ON BIOLOGICAL RESOURCES
The capacity for a given natural open space area to maintain its ecological integrity (e.g.,
its resistance to invasion by exotic species, capacity to support special-status species)
depends upon such considerations as (a) size, with larger natural areas generally
possessing greater ecological value than do smaller ones; (b) plant communities
represented, with relatively undisturbed native communities generally being more
valuable than disturbed non-native communities; and (c) proximity to adjacent open
spaces, with areas linked to other natural areas generally possessing greater ecological
value compared with areas of similar size that are functionally isolated from other
natural areas.
A small, functionally isolated area that provides habitat for a rare plant or wildlife
species may have some ecological value, but conservation of such areas may prove to be
practically infeasible due to habitat degradation that often occurs near development
edges. Ecologically damaging “edge effects” include repeated clearing of habitat for fuel
modification leading to replacement of native plants with disturbance-adapted exotic
weeds; invasion of natural habitat by exotic ants facilitated by artificial irrigation near
homes; predation of birds, reptiles, and mammals by outdoor cats; and changes in
wildlife patterns associated with exterior lighting. To avoid perpetuating damaging
patterns of development that result in ever-smaller blocks of functionally isolated
habitat, the Open Space and Conservation Element must contain land-use policies that
encourage the preservation, restoration, and appropriate management of larger blocks
of well-connected habitat.
Readers seeking detailed information on these topics, with relevant citations from the
scientific literature, should refer to Appendix A.
30
Edge/Fragmentation Effects on Wildlife Movement
Constricting the movement of wildlife and plant seeds increases the risk of local
extinctions. Habitat fragmentation consequently threatens the viability of native plant
and wildlife populations in preserved areas. Large areas of habitat, or narrower
linkages of habitat between large areas, provide movement opportunities for wildlife.
Movement serves to facilitate the geographic distribution of genetic material, thus
maintaining a level of variability in the gene pool of an animal population. Influxes of
animals from nearby larger populations contribute to the genetic diversity of a local
population, helping to ensure the population’s ability to adapt to changing
environmental conditions. This is mainly accomplished through the dispersal of
juveniles from their natal territories, but may also involve movements in response to
drought or other adverse environmental conditions, or in response to wildfires or other
catastrophic events. Many plant species that depend on relatively sedentary insects for
pollination also benefit from habitat linkages that allow for genetic exchange and
dispersal. Likewise, plant seeds and propagules can be transported via the feces, fur, or
feathers of birds or mammals. Fragmentation effects are not limited to the physical
severing of movement routes, such as through the construction of a road or housing
development, but can include “edge effects” reviewed and described above. For
example, increases in night lighting and noise can disrupt the movement patterns of
species not well-adapted to such effects.
WILDLIFE MOVEMENT ISSUES IN THE PUENTE-CHINO HILLS
The Puente-Chino Hills ecosystem encompasses portions of four counties, and the open
space network in this area is sometimes referred to as the “Puente-Chino Hills Wildlife
Corridor.” Preserving land in the corridor has been a cooperative endeavor with other
public agencies and many nonprofit organizations. An important analysis by the
Conservation Biology Institute (2005), Maintaining Ecological Connectivity Across the
“Missing Middle” of the Puente-Chino Hills Wildlife Corridor, describes the situation as
follows (page v):
The Puente-Chino Hills Wildlife Corridor is a peninsula of mostly undeveloped hills jutting
about 42 km (26 miles) from the Santa Ana Mountains into the heart of the densely
urbanized Los Angeles Basin. Intense public interest in conserving open space here has
created a series of reserves and parks along most of the corridor’s length, but significant
gaps in protection remain. These natural habitat areas support a surprising diversity of
native wildlife, from mountain lions and mule deer to walnut groves, roadrunners, and
horned lizards. But maintaining this diversity of life requires maintaining functional
connections along the entire length of the corridor, so that wildlife can move between
reserves—from one end of the hills to the other.
Already the corridor is fragmented by development and crossed by numerous busy roads,
which create hazards and in some cases barriers to wildlife movement. Proposed
developments threaten to further degrade or even sever the movement corridor, especially
within its so-called “Missing Middle.” This mid-section of the corridor system, stretching
from Tonner Canyon on the east to Harbor Boulevard on the west, includes several large
properties proposed for new housing, roads, golf courses, and reservoirs. Such
31
developments would reduce habitat area and the capacity to support area-dependent
species and, if poorly designed, could block wildlife movement through the corridor.
The above-quoted report considered numerous studies of wildlife movement conducted
in the Puente-Chino Hills, and other relevant literature on wildlife movement corridors,
and recommended “conservation and management actions to prevent further loss of
ecological connectivity and retain native species.” The “Missing Middle” analysis
identified the following wildlife movement issues specifically relevant to Diamond Bar
and its Sphere of Influence:
• Tonner Canyon Bridge represents the only viable location for deer, mountain lions,
bobcats, and other species to pass under the 57 Freeway.
• Any development in middle and especially lower Tonner Canyon could have
severe impacts on corridor function, especially if wildlife access to Tonner Canyon
Bridge is reduced. Any development that blocks access through the bridge area
would make the 57 Freeway a complete barrier to many species and would likely
lead to wildlife extirpations in segments farther west.
• An earlier plan to build a road running the length of Tonner Canyon would have
split the Chino-Tonner “subcore” in two, potentially rendering dysfunctional the
critical Tonner Bridge wildlife undercrossing for wide-ranging species such as the
mountain lion, bobcat, and mule deer.
• At least the middle and lower portions of Tonner Canyon should be conserved,
including a prohibition on any new road or other development that would fragment
this critical habitat block.
• No project should be approved that would increase traffic under the Tonner Bridge
or add any new impediments (structures, lights, noise, etc.) to the vicinity of the
bridge.
• Restore riparian vegetation along Tonner Creek, where degraded by oil
development activities.
• Fencing may be warranted along the 57 Freeway if monitoring suggests road
mortality is high.
Planning of any future development in Diamond Bar and its Sphere of Influence should
take exceptional care to preserve and enhance the viability of the Puente-Chino Hills
Wildlife Corridor.
Regional Planning in the Puente-Chino Hills Wildlife Corridor
Two agencies are specifically involved in planning development and taking
conservation actions in and around the Puente-Chino Hills Wildlife Corridor.
The Wildlife Corridor Conservation Authority (WCCA) was established to provide for
the proper planning, conservation, environmental protection, and maintenance of lands
32
within and around the Puente-Chino Hills Wildlife Corridor. Its goal is to assure that
sufficient continuity of habitat can be preserved to maintain a functioning wildlife
corridor made up of about 40,000 acres of land located between the Santa Ana
Mountains and Whittier Hills. The governing board of the WCCA consists of
representatives from the cities of Brea, Whittier, Diamond Bar, La Habra Heights, the
Santa Monica Mountains Conservancy, California Department of Parks and Recreation,
California Department of Fish and Game (ex officio member), Los Angeles County, and
two public members. A large Advisory Committee meets separately to provide input.
The WCCA consistently provides comments on development proposals and other
projects to support environmentally sensitive activities in the Puente-Chino Hills
Wildlife Corridor.
The Puente Hills Habitat Preservation Authority (PHHPA) is a public agency, Joint
Powers Authority, with a Board of Directors consisting of the City of Whittier, County
of Los Angeles, Sanitation Districts of Los Angeles County, and the Hacienda Heights
Improvement Association. The jurisdiction of the PHHPA extends from the intersection
of the 605 and 60 Freeways east to Harbor Boulevard. The PHHPA is dedicated to the
acquisition, restoration, and management of open space in the Puente Hills for
preservation of the land in perpetuity, with the primary purpose to protect the
biological diversity.
NATURAL RESOURCE CONSERVATION POLICIES
The City of Diamond Bar has developed a suite of conservation measures, presented in
this section, designed to allow for the planned growth of the City while protecting and
conserving irreplaceable natural communities and their component species. These
policies align the local approach to development with the conservation regulations and
policies set forth by the federal government (e.g., the federal Endangered Species Act);
the State of California (e.g., the California Environmental Quality Act and the California
Fish and Game Code); and local entities (e.g., the Los Angeles County Oak Woodlands
Conservation Plan; see Los Angeles County Oak Woodlands Habitat Conservation
Strategic Alliance 2011, Los Angeles County Dept. of Regional Planning 2014).
Prioritizing the identification and protection of sensitive natural resources facilitates
efforts of City planners and elected officials to ensure that Diamond Bar remains a
beautiful and desirable place to live.
Goals and Policies of the Open Space and Conservation Element
• RC-I-1. Obtain and designate Open Space land through acquisition techniques,
such as:
a. Design new development projects emphasizing preservation of sensitive natural
resources, natural geological features, and wildlife corridors and habitat
linkages, through site design approaches that include greenbelts, landscaping
with locally native, drought-adapted plants, and dedication of a portion of the
site as natural open space.
33
b. Allow for acquisition of open space lands during the entitlement process
through the transfer of densities among land uses of like designation.
c. Identify ecologically sensitive/unique habitats, including habitat linkages and
choke-points, within the City of Diamond Bar and prioritize their
acquisition/preservation/restoration as a preferred form of mitigation for future
development.
d. Collaborate with land trusts, joint-power authorities, and other conservation
groups to acquire and restore open space land through, but not limited to,
conservation easements and conservation plans.
• RC-I-2. As future parks are developed or open space is acquired/dedicated:
a. Preserve sensitive natural communities to maintain ecological integrity and
provide for passive recreation opportunities, such as hiking and bird-watching.
b. Site trails to avoid removal or fragmentation of sensitive natural communities
and to minimize erosion.
c. Prohibit the application of use of outdoor pesticide bait stations, or similar,
within 500 feet of any natural open space.
• RC-G-4. Provide recreational and cultural opportunities to the public in a
manner that maintains, restores, protects, and preserves sensitive natural
resources in the City of Diamond Bar and its Sphere of Influence.
• RC-I-12. Support and cooperate with efforts to identify and preserve
environmentally sensitive and strategically located canyon areas and hillsides
that serve as wildlife corridors and habitat linkages/choke points within
Diamond Bar and its Sphere of Influence, including components of the Puente-
Chino Hills Wildlife Corridor, Tres Hermanos Ranch, Tonner Canyon, and
Significant Ecological Area (SEA) 15, to provide regional connectivity, and to
sustain the ecological function of natural habitats and biological resources.
a. Establish appropriate resource protection overlays for ecologically sensitive
areas (see page 18 of this report).
b. Require adequate biological resources surveys as part of planning of
development proposed in any area with potential for special-status species
or sensitive natural communities to occur.
c. Discourage development in areas with identified sensitive natural resources,
natural geological features, and wildlife corridors and habitat linkages/choke
points, in order to preserve them in a natural state, unaltered by grading, fill,
or diversion activities (except as may be desirable for purposes of habitat
restoration and/or facilitation of wildlife movement).
34
d. Preserve and restore native woodlands in perpetuity, with a goal of no net
loss of existing woodlands, through compliance with Chapter 22.38 of the
Diamond Bar – Tree Preservation and Protection.
e. In the unincorporated Sphere of Influence, require that impacts to native oak
trees be treated in a manner consistent with Section 22.46.2100 of the
County of Los Angeles Code of Ordinances, except that in-lieu fees shall not
be accepted as mitigation for removal of regulated oaks. If replacement of
oaks is determined to be necessary, this should be conducted under a City-
administered Tree Mitigation Program developed in consultation with a
qualified biologist and Certified Arborist or Certified Urban Forester to
establish a to ensure that replacement trees are planted on public property
in areas that (a) shall not impact any existing sensitive habitat areas; (b) are
appropriate for the long-term survival of native trees planted as mitigation;
and (c) shall be maintained and preserved by the city, in perpetuity, as
natural open space for the mitigation trees and any associated understory
species deemed appropriate to provide valuable woodland habitat.
f. For development proposed adjacent to natural open space, require use of
highly fire-resistant building materials and methods, which minimize fuel
modification treatments.
g. In areas adjacent to natural open space, require use of highly fire-resistant
building materials and architecture for public safety and to minimize
requirements for damaging fuel modification treatments.
h. Fuel modification adjacent to natural open spaces should employ
exclusively native plant species approved for use in fuel modification zones,
which provide important habitat for native wildlife and minimize ongoing
irrigation and disturbance of the exterior slopes, reducing the potential for
exotic ants and weeds to become established on the site and then spread to
nearby natural open space areas.
• RC-I-28.5. Conserve natural open spaces, biological resources, and vegetation,
recognizing their roles in the reduction and mitigation of air pollution impacts,
and the promotion of carbon sequestration.
LITERATURE CITED
Allen, L. W., and Los Angeles County Sensitive Bird Species Working Group. 2009. Los Angeles County’s
Sensitive Bird Species. Western Tanager 75(3):E1–E11.
City of Diamond Bar and Diamond Bar Historical Society. 2014. Images of America, Diamond Bar. Arcadia
Publishing, Charleston, South Carolina.
Conservation Biology Institute. 2005. Maintaining Ecological Connectivity Across the “Missing Middle” of
the Puente-Chino Hills Wildlife Corridor. Encinitas, CA.
https://d2k78bk4kdhbpr.cloudfront.net/media/reports/files/pcmissingmiddle.pdf
35
Dyett & Bhatia. 2017. City of Diamond Bar General Plan Update, Existing Conditions Report – Volume III.
Redline draft dated February 21, 2017, prepared for City of Diamond Bar.
Los Angeles County, Dept. of Regional Planning. 2014. Los Angeles County Oak Woodlands Conservation
Management Plan Guide. Report dated March 18, 2014.
http://planning.lacounty.gov/assets/upl/project/oakwoodlands_conservation-management-plan-
guide.pdf
Los Angeles County Oak Woodlands Habitat Conservation Strategic Alliance. 2011. Los Angeles County
Oak Woodlands Conservation Management Plan. Report dated May 2011.
http://file.lacounty.gov/SDSInter/bos/bc/162273_official_20110620_oak-woodlands.pdf
Lower San Gabriel River Watershed Group. 2015. Lower San Gabriel River Watershed Management
Program.
https://www.waterboards.ca.gov/rwqcb4/waterissues/programs/stormwater/municipal/watershedman
agement/sangabriel/lowersangabriel/LowerSGRiverFinalWMP.pdf
Neal, S. 2011. Brea History – the Brea Creek. Brea Historical Society Brea Museum & Heritage Center.
Sage Environmental Group. 2012. Affordable Housing Land Use and Zoning Designation Project, Biological
Survey Report. Report dated August 2012 prepared for City of Diamond Bar.
Sheng, J. and J. P. Wilson. 2008. The Green Visions Plan for 21st Century Southern California. 16.
Watershed Assets Assessment Report. University of Southern California GIS Research Laboratory
and Center for Sustainable Cities, Los Angeles, CA.
U.S. Army Corps of Engineers. 1991. Los Angeles County Drainage Area Review, Final Feasibility Study,
Interim Report and Environmental Impact Statement. Vandergast, A. G., A. J. Bohonak, D. B.
Weissman, and R. N. Fisher. 2006. Understanding the genetic effects of recent habitat fragmentation
in the context of evolutionary history: Phylogeography and landscape genetics of a southern
California endemic Jerusalem cricket (Orthoptera: Stenopelmatidae: Stenopelmatus). Molecular
Ecology 16:977–92.
H AMILTON B IOLOGICAL
February 20, 2019
Greg Gubman
Director of Community Development
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
SUBJECT: APPENDIX A TO OPEN SPACE AND CONSERVATION ELEMENT
DIAMOND BAR GENERAL PLAN UPDATE
METHODS AND TECHNICAL INFORMATION
Dear Mr. Gubman,
A consortium of Diamond Bar residents retained Hamilton Biological, Inc., (hereafter
“Hamilton Biological”) to prepare an Open Space and Conservation Element for the
City of Diamond Bar (hereafter the “City”) to consider incorporating into a forthcoming
update to its General Plan. This letter describes the methods used to prepare the pro-
posed Open Space and Conservation Element, and provides technical biological infor-
mation that underpins the report’s findings and recommendations.
METHODS
Literature Review
As an initial step, Robert Hamilton, President of Hamilton Biological, reviewed the Bio-
logical Resources section of Dyett & Bhatia (2017) and a partial rough draft of an Open
Space and Conservation Element prepared by Cooper Ecological Monitoring, Inc. Mr.
Hamilton also reviewed a biological report prepared by Sage Environmental Group
(2012) for an Affordable Housing Land Use and Zoning Designation Project proposed
on a site covering 78 acres in the northeastern part of the City, near Diamond Ranch
High School.
Special-status species with potential to occur in Diamond Bar and adjacent areas were
identified through review of the California Natural Diversity Database (2018a, 2018b,
2018c) and searches of eBird (https://ebird.org); California Native Plant Society’s
Online Inventory of Rare and Endangered Plants (www.rareplants.cnps.org); review of
the list of Los Angeles County’s Sensitive Bird Species (Allen et al. 2009;
https://losangelesaudubon.org/images/stories/pdf/WesternTanager_pdfs/Vol.75/vo
l75no03jan-feb2009.pdf); the Consortium of California Herbaria web page
(www.ucjeps.berkeley.edu/consortium); Sage Environmental Group (2012); Dyett &
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 2 of 9
Bhatia (2017); and the online Flora of the Skyline Trail, Puente Hills, Los Angeles County
(Muns, B., 1982; http://tchester.org/plants/muns/pr/skyline_trail.html).
Mapping and Field Surveys
Robert A. Hamilton mapped the natural open space areas throughout the City and its
Sphere of Influence using Google Earth Pro. Potential habitat linkages and/or choke-
points for wildlife movement were identified by examination of aerial imagery. Mr.
Hamilton conducted reconnaissance field surveys on January 4 and 8, and February 4
and 8, 2019, to field-check the mapping and to observe the existing conditions through-
out most of Diamond Bar. Mr. Hamilton has visited the portion of Tonner Canyon that
lies within the City’s Sphere of Influence on numerous occasions in recent years, and
thus has viewed the natural resources found in that part of the study area, as well.
Classification of Natural Communities
Since the mid-1990s, CDFW and its partners, including the California Native Plant
Society (CNPS), have been working on classifying vegetation types using standards
embodied in the Survey of California Vegetation, which comply with the National
Vegetation Classification Standard (NVCS; http://usnvc.org/explore-classification/). The
NVCS is a hierarchical classification, with the most granular level being the Association.
Associations are grouped into Alliances, Alliances into Groups, and upward, as follows:
Formation Class > Formation Subclass > Formation > Division > Macrogroup > Group
> Alliance > Association. For purposes of this Open Space and Conservation Element,
Natural Communities are generally classified at the more generalized levels (e.g.,
Group), but for environmental review of specific projects in Diamond Bar, Natural
Communities should be classified and mapped at the more detailed Alliance or
Association level.
The method recommended by CDFW for classifying Natural Communities and
conducting CEQA review reads as follows:
• Identify all Natural Communities within the project footprint using the best means
possible, for example, keying them out in the Manual of California Vegetation,
Second Edition (Sawyer et al. 2009) or in classification or mapping reports from the
region, available on VegCAMP’s Reports and Maps page.
• Refer to the current standard list of Natural Communities to determine if any of
these types are ranked Sensitive (S1-S3 rank); if so, see CEQA Guidelines checklist
at IVb.
• Other considerations when assessing potential impacts to Sensitive Natural
Communities from a project include:
1. Compliance with state and federal wetland and riparian policies and codes,
as certain Natural Communities are restricted to wetlands or riparian set-
tings.
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 3 of 9
2. Compliance with the Native Plant Protection Act and the state and federal
Endangered Species Acts, as some Natural Communities either support rare
species or are defined by the dominance or presence of such species.
3. Compliance with CEQA Guidelines Section 15065(a), which mandates
completion of an EIR if a project would threaten to eliminate a plant com-
munity.
4. Compliance with local regional plans, regulations, or ordinances that call
for consideration of impacts to Natural Communities.
5. Vegetation types that are not on the state’s sensitive list but that may be con-
sidered rare or unique to the region under CEQA Guidelines Section
15125(c).
• If a Natural Community in the project area has not previously been described, it
may be a rare type. In this case, please contact VegCAMP (Todd Keeler-Wolf or
Diana Hickson) about documenting the Natural Community.
• If there are Sensitive Natural Communities on your project site and you need
guidance, contact the appropriate regional staff person through the local CDFW
Regional Office to discuss potential project impacts; these staff have local
knowledge and context.
Identifying Sensitive Natural Communities
The California Department of Fish and Wildlife (CDFW), at its VegCAMP page, pro-
vides guidance on appropriate methods for “Addressing Sensitive Natural Communi-
ties in Environmental Review”:
https://www.wildlife.ca.gov/Data/VegCAMP/Natural-Communities#sensitive%20natural%20communities
The State’s guidance consists of the following steps:
• Identify all Natural Communities within the project footprint using the best means
possible, for example, keying them out in the Manual of California, Second Edition
(Sawyer et al. 2009) or in classification or mapping reports from the region,
available on VegCAMP’s Reports and Maps page.
• Refer to the current standard list of Natural Communities to determine if any of
these types are ranked Sensitive (S1-S3 rank); if so, see CEQA Guidelines checklist
at IVb.
• Other considerations when assessing potential impacts to Sensitive Natural
Communities from a project include:
o Compliance with state and federal wetland and riparian policies and codes,
as certain Natural Communities are restricted to wetlands or riparian set-
tings.
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 4 of 9
o Compliance with the Native Plant Protection Act and the state and federal
Endangered Species Acts, as some Natural Communities either support rare
species or are defined by the dominance or presence of such species.
o Compliance with CEQA Guidelines Section 15065(a), which mandates
completion of an EIR if a project would threaten to eliminate a plant com-
munity.
o Compliance with local regional plans, regulations, or ordinances that call
for consideration of impacts to Natural Communities.
• Vegetation types that are not on the State’s sensitive list but that may be considered
rare or unique to the region under CEQA Guidelines Section 15125(c).
• If a Natural Community in the project area has not previously been described, it
may be a rare type. In this case, please contact VegCAMP (Todd Keeler-Wolf or
Diana Hickson) about documenting the Natural Community.
• If there are Sensitive Natural Communities on your project site and you need guid-
ance, contact the appropriate regional staff person through the local CDFW Re-
gional Office to discuss potential project impacts; these staff have local knowledge
and context.
• The Department’s document, Protocols for Surveying and Evaluating Impacts to
Special Status Native Plant Populations and Natural Communities (PDF) provides
information on reporting.
The City of Diamond Bar should employ the above-described methods to ensure the
thoroughness and adequacy of CEQA documentation completed within the City and its
Sphere of Influence.
Important Considerations for Oak Woodlands
As of January 2005, California Public Resources Code Section 21083.4 (2004 Senate Bill
1334) requires that when a county is determining the applicability of CEQA to a project,
it must determine whether that project “may result in a conversion of oak woodlands
that will have a significant effect on the environment.” If such effects (either individual
impacts or cumulative) are identified, the law requires that they be mitigated. Accepta-
ble mitigation measures include, but are not limited to, conservation of other oak wood-
lands through the use of conservation easements and planting replacement trees, which
must be maintained for seven years.
Diamond Bar’s Sphere of Influence, south of the city limits, lies within unincorporated
Los Angeles County, and thus the City’s General Plan should acknowledge that the
County of Los Angeles Department of Regional Planning issued in 2014 an Oak Wood-
lands Conservation Management Plan Guide1, with three important objectives: (1) pri-
1 http://planning.lacounty.gov/assets/upl/project/oakwoodlands_conservation-management-plan-guide.pdf
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 5 of 9
oritize the preservation of oak woodlands; (2) promote conservation by integrating oak
woodlands into the development process in a sustainable manner; and (3) effectively
mitigate the loss of oak woodlands.
ADVERSE EFFECTS OF DEVELOPMENT ON PRESERVED HABITAT AREAS
One purpose of a General Plan is to guide future development so as to minimize ad-
verse effects upon sensitive Natural Communities and declining native plant and wild-
life populations, to the extent feasible. Beyond the outright removal of natural areas,
which obviously impacts natural resources, development projects inevitably degrade
and fragment habitats along the urban/wildland interface. Such secondary, or indirect,
impacts have been subject to intensive study in recent years, to (a) understand and
characterize them, and (b) develop strategies for minimizing and mitigating them. The
following discussions, including citations from the scientific literature, provide the basis
for the General Plan’s land-use policies concerning edge and fragmentation effects.
Urbanization typically includes residential, commercial, industrial, and road-related
development. At the perimeter of the built environment is an area known as the ur-
ban/wildland interface, or “development edge.” Edges are places where natural com-
munities interface, vegetation or ecological conditions within natural communities in-
teract (Noss 1983), or patches with differing qualities abut one another (Ries and Sisk
2004). “Edge effects” are spillover effects from the adjacent human-modified matrix
that cause physical gradients in light, moisture, noise, etc. (Camargo and Kapos 1995;
Murcia 1995, Sisk et al. 1997) and/or changes in biotic factors such as predator commu-
nities, density of human-adapted species, and food availability (Soulé et al. 1988;
Matlack 1994; Murcia 1995; Ries and Sisk 2004). Loss, degradation, and fragmentation of
habitat due to urbanization are the most pervasive threats to biodiversity in southern
California (Soulé 1991). Edge-related impacts may include:
• Introduction/expansion of invasive exotic vegetation carried in from vehicles, peo-
ple, animals or spread from backyards or fuel modification zones adjacent to
wildlands.
• Increased frequency and/or severity of fire as compared to natural fire cycles or in-
tensities.
• Companion animals (pets) that often act as predators of, and/or competitors with,
native wildlife.
• Creation and use of trails that often significantly degrade intact ecosystems through
such changes as increases in soil disturbance, vegetation damage, and noise.
• Introduction of or increased use by exotic animals which compete with or prey on
native animals.
• Pesticide exposure can be linked to cancer, endocrine disruption, reproductive ef-
fects, neurotoxicity, kidney and liver damage, birth defects, and developmental
changes in a wide range of species, from insects to top predators.
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February 20, 2019 Page 6 of 9
• Influence on earth systems and ecosystem processes, such as solar radiation, soil
richness and erosion, wind damage, hydrologic cycle, and water pollution that can
affect the natural environment.
Any of these impacts, individually or in combination, can result in the effective loss or
degradation of habitats used for foraging, breeding or resting, with concomitant effects
on population demographic rates of sensitive species.
The coastal slope of southern California is among the most highly fragmented and ur-
banized regions in North America (Atwood 1993). Urbanization has already claimed
more than 90 percent of the region’s coastal sage scrub habitat, 99 percent of the coastal
prairie, and 95 percent of the vernal pools (McCaull 1994; Mattoni & Longcore 1997;
Bauder & McMillan 1998). A review of studies completed by Harrison and Bruna (1999)
identified a general pattern of reduction of biological diversity in fragmented habitats
compared with more intact ones, particularly with regard to habitat specialists. While
physical effects associated with edges were predominant among species impacts, they
found evidence for indirect effects including altered ecological interactions. Fletcher et
al. (2007) found that distance from edge had a stronger effect on species than did habitat
patch size, but they acknowledged the difficulty in separating those effects empirically.
Many southern California plant and animal species are known to be sensitive to frag-
mentation and edge effects; that is, their abundance declines with fragment size and
proximity to an edge (Wilcove 1985; Soulé et al. 1992; Bolger et al. 1997a,b; Suarez et al.
1998; Burke and Nol 2000).
Wildlife populations are typically changed in proximity to edges, either by changes in
their demographic rates (survival and fecundity), or through behavioral avoidance of or
attraction to the edge (Sisk et al. 1997; Ries and Sisk 2004). For example, coastal sage
scrub areas within 250 meters of urban edges consistently contain significantly less bare
ground and more coarse vegetative litter than do more “intermediate” or “interior” are-
as, presumably due increased human activity/disturbance of the vegetation structure
near edges (Kristan et al. 2003). Increases in vegetative litter often facilitate growth of
non-native plants (particularly grasses), resulting in a positive feedback loop likely to
enhance plant invasion success (Wolkovich et al. 2009). In another coastal southern Cali-
fornia example, the abundance of native bird species sensitive to disturbance is typical-
ly depressed within 200 to 500 meters (650 to 1640 feet) of an urban edge, and the abun-
dance of disturbance-tolerant species is elevated up to 1000 meters (3280 feet) from an
urban edge, depending on the species (Bolger et al. 1997a).
Habitat fragmentation is usually defined as a landscape scale process involving habitat
loss and breaking apart of habitats (Fahrig 2003). Habitat fragmentation is among the
most important of all threats to global biodiversity; edge effects (particularly the diverse
physical and biotic alterations associated with the artificial boundaries of fragments) are
dominant drivers of change in many fragmented landscapes (Laurance and Bierregaard
1997; Laurance et al. 2007).
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Fragmentation decreases the connectivity of the landscape while increasing both edge
and remnant habitats. Urban and agricultural development often fragments wildland
ecosystems and creates sharp edges between the natural and human-altered habitats.
Edge effects for many species indirectly reduce available habitat use or utility in sur-
rounding remaining areas; these species experience fine-scale functional habitat losses
(e.g., see Bolger et al. 2000; Kristan et al. 2003; Drolet et al. 2016). Losses of coastal sage
scrub in southern California have increased isolation of the remaining habitat fragments
(O’Leary 1990) and led to calls to preserve and restore landscape connectivity to permit
long-term persistence of native species with low vagility (e.g., Vandergast et al. 2006).
Fragmentation has a greater relative negative impact on specialist species (e.g., coastal
populations of the Cactus Wren, Campylorhynchus brunneicapillus) that have strict vege-
tation structure and area habitat requirements (Soulé et al. 1992). Specialist species have
an increased risk of extirpation in isolated habitat remnants because the specialized
vegetative structures and/or interspecific relationships on which they depend are more
vulnerable to disruption in these areas (Vaughan 2010). In studies of the coastal sage
scrub and chaparral systems of coastal southern California, fragment area and age (time
since isolation) were the most important landscape predictors of the distribution and
abundance of native plants (Soulé et al. 1993), scrub-breeding birds (Soulé et al. 1988;
Crooks et al. 2001), native rodents (Bolger et al. 1997b), and invertebrates (Suarez et al.
1998; Bolger et al. 2000).
Edge effects that emanate from the human-dominated matrix can increase the extinction
probability of isolated populations (Murcia 1995; Woodroffe and Ginsberg 1998). In
studies of coastal sage scrub urban fragments, exotic cover and distance to the urban
edge were the strongest local predictors of native and exotic carnivore distribution and
abundance (Crooks 2002). These two variables were correlated, with more exotic cover
and less native shrub cover closer to the urban edge (Crooks 2002).
The increased presence of human-tolerant “mesopredators” in southern California rep-
resents an edge effect of development; they occur within the developed matrix and are
thus more abundant along the edges of habitat fragments, and they are effective preda-
tors on birds, bird nests, and other vertebrates in coastal sage scrub and chaparral sys-
tems and elsewhere (Crooks and Soulé 1999). The mammalian carnivores more typically
detected in coastal southern California habitat fragments are resource generalists that
likely benefit from the supplemental food resources (e.g., garden fruits and vegetables,
garbage, direct feeding by humans) associated with residential developments. As a re-
sult, the overall mesopredator abundance, of such species as raccoons (Procyon lotor),
opossums (Didelphis virginiana), and domestic cats (Felis catus), increases at sites with
more exotic plant cover and closer to the urban edge (Crooks 2002). Although some
carnivores within coastal sage scrub fragments seem tolerant of disturbance, many
fragments have (either actually or effectively) already lost an entire suite of predator
species, including mountain lion, bobcats (Lynx rufus), spotted skunks (Spilogale gracilis),
long-tailed weasels (Mustela frenata), and badgers (Taxidea taxus) (Crooks 2002). Most
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February 20, 2019 Page 8 of 9
“interior” sites within such fragments are still relatively near (within 250 meters of) ur-
ban edges (Crooks 2002).
Fragmentation generally increases the amount of edge per unit land area, and species
that are adversely affected by edges can experience reduced effective area of suitable
habitat (Temple and Cary 1988), which can lead to increased probability of extirpa-
tion/extinction in fragmented landscapes (Woodroffe and Ginsberg 1998). For example,
diversity of native bees (Hung et al. 2015) and native rodents (Bolger et al. 1997b) is
lower, and decomposition and nutrient cycling are significantly reduced (Treseder and
McGuire 2009), within fragmented coastal sage scrub ecosystems as compared to larger
core reserves. Similarly, habitat fragmentation and alterations of sage scrub habitats
likely have reduced both the genetic connectivity and diversity of coastal-slope popula-
tions of the Cactus Wren in southern California (Barr et al. 2015). Both Bell’s Sparrows
(Artemisiospiza belli) and California Thrashers (Toxostoma redivivum) show strong evi-
dence of direct, negative behavioral responses to edges in coastal sage scrub; that is,
they are edge-averse (Kristan et al. 2003), and California Thrashers and California Quail
(Callipepla californica) were found to be more vulnerable to extirpation with smaller
fragment size of the habitat patch (Bolger et al. 1991), demonstrating that both behav-
ioral and demographic parameters can be involved. Other species in coastal sage scrub
ecosystems, particularly the Cactus Wren and likely the California Gnatcatcher and San
Diego Pocket Mouse (Chaetodipus fallax), are likely vulnerable to fragmentation, but for
these species the mechanism is likely to be associated only with extirpation vulnerabil-
ity from habitat degradation and isolation rather than aversion to the habitat edge (Kris-
tan et al. 2003). Bolger (et al. 1997b) found that San Diego coastal sage scrub and chapar-
ral canyon fragments under 60 acres that had been isolated for at least 30 years support
very few populations of native rodents, and they suggested that fragments larger than
200 acres in size are needed to sustain native rodent species populations.
The penetration of exotic species into natural areas can reduce the effective size of a re-
serve in proportion to the distance they penetrate within the reserve: Argentine Ants
serve as an in-depth example of edge effects and fragmentation. Spatial patterns of Ar-
gentine Ant abundance in scrub communities of southern California indicate that they
are likely invading native habitats from adjacent developed areas, as most areas sam-
pled greater than 200 to 250 meters from an urban edge contained relatively few or no
Argentine Ants (Bolger 2007, Mitrovich et al. 2010). The extent of Argentine Ant inva-
sions in natural environments is determined in part by inputs of urban and agricultural
water run off (Holway and Suarez 2006). Native ant species were more abundant away
from edges and in areas with predominately native vegetation. Post-fragmentation edge
effects likely reduce the ability of fragments to retain native ant species; fragments had
fewer native ant species than similar-sized plots within large unfragmented areas, and
fragments with Argentine ant-free refugia had more native ant species than those with-
out refugia (Suarez et al. 1998). They displace nearly all surface-foraging native ant spe-
cies (Holway and Suarez 2006) and strongly affect all native ant communities within
about 150 to 200 meters from fragment edges (Suarez et al. 1998; Holway 2005; Fisher et
al. 2002; Bolger 2007; Mitrovich et al. 2010). Argentine Ants are widespread in frag-
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 9 of 9
mented coastal scrub habitats in southern California, and much of the remaining poten-
tial habitat for Blainville’s Horned Lizards (Phrynosoma blainvillii) is effectively unsuita-
ble due to the penetration of Argentine ants and the subsequent displacement of the na-
tive ant species that Coastal Horned Lizards need as prey (Fisher et al. 2002). Invasion
of Argentine Ants into coastal sage scrub has also shown a strong negative effect on the
abundance of the gray shrew (Notiosorex crawfordi) (Laakkonen et al. 2001).
An evaluation by the U.S. Environmental Protection Agency (2008) concluded that each
of ten of the most common active ingredients in rodenticides “poses significant risks to
non-target wildlife when applied as grain-based bait products. The risks to wildlife are
from primary exposure (direct consumption of rodenticide bait) for all compounds and
secondary exposure (consumption of prey by predators or scavengers with rodenticide
stored in body tissues) from the anticoagulants.” Thus, the common practice of setting
out bait within or near natural areas can be expected to have adverse effects upon a
range of native wildlife species.
Finally, in the Santa Monica Mountains of Los Angeles County, populations of such na-
tive amphibians as the California newt (Taricha torosa) and California treefrog
(Pseudacris cadaverina) were found to decline with urbanization of as little as 8% of a
given watershed (Riley et al. 2005). Such faunal community changes appear to be relat-
ed to changes in physical stream habitat, such as fewer pool and more run habitats and
increased water depth and flow. These changes are associated with increased erosion
and with invasion by damaging exotic species, such as the red swamp crayfish (Procam-
barus clarkii).
CONCLUSION
I appreciate the opportunity to provide this technical informtion in support of the Open
Space and Conservation Element for the Diamond Bar General Plan. If you have ques-
tions, please call me at (562) 477-2181 or send e-mail to robb@hamiltonbiological.com.
Sincerely,
Robert A. Hamilton
President, Hamilton Biological, Inc.
316 Monrovia Avenue
Long Beach, CA 90803
562-477-2181
robb@hamiltonbiological.com
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Page 1
CHAPTER 22.38. - TREE PRESERVATION AND PROTECTION Redline Draft April 2016
Comments in red input David Haas/CalFire Urban Forester, John Melvin, CalFire,
Yellow input Cynthia Smith
Sec. 22.38.010. - Purpose. 099
One of the city's most important resources is the beauty of its natural environment. Native trees are a
significant part of this environment. While impacted by development over the years, several areas in the
city still contain native oak, walnut, and riparian woodlands which support species of trees important to
our natural heritage.
Trees are an important natural resource, contributing to the environment by replenishing oxygen and
counteracting air pollution, controlling soil erosion, and providing wildlife habitat. Trees are an aesthetic
asset which provide scale, color, aroma, shade, visual buffers between land uses, and increased property
value. It is essential to the public peace, health, and welfare that such trees be protected from random
removal or cutting, especially where such trees are associated with a proposal for development.
[The] general plan, as the overall policy document for the city, requires the preservation and
maintenance of native trees including oak, walnut, sycamore, willow, signi ficant trees of cultural or
historical value and pepper trees where appropriate. The purpose of this chapter is to protect and
preserve these trees and when removal is allowed as a result of new development to require their
replacement.
(Ord. No. 02(1998), § 2, 11-3-98; Ord. No. 02(2003), 9-16-03)
Sec. 22.38.020. - Applicability.
The provisions of this chapter shall apply in all zoning districts to the removal, relocation or pruning
of protected trees as provided in section 22.38.030 (Protected trees). Ex ceptions to the provisions of this
chapter are outlined in section 22.38.060 (Exemptions).
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.030. - Protected trees.
A protected tree is any of the following:
(1) Native Oak, walnut, sycamore and willow trees w ith a diameter at breast height (DBH) of eight
five inches or greater; (per SB 1334)
(2) Trees of significant historical value as designated by the council;
(3) Any tree required to be preserved or relocated as a condition of approval for a discretionary
permit;
(4) Any tree required to be planted as a condition of approval for a discretionary permit; and
(5) A stand of trees, the nature of which makes each tree dependent upon the others for survival.
(Ord. No. 02(1998), § 2, 11-3-98; Ord. No. 02(2003), 9-16-03; Ord. No. 04(2012), § 9, 4-17-12)
Sec. 22.38.040. - Damaging protected trees prohibited.
Page 2
Except as provided in section 22.38.060 (Exemptions), no person shall cut, prune, remove, relocate,
or otherwise destroy a protected tree.
The topping of protected trees is prohibited. No reduction of the tree crown shall be permitted without
a tree pruning permit and then only by "thinning out" selected branches in compliance with guidelines
published by the National Arborists Association. No longer exists, now Tree Care Industry Association.
Current nationwide tree care and maintenance guidelines are ANSI A300 standards. For sake of ease, a
statement can be made stating all tree work done must conform to AN SI A300 standards. Also, include
all work must be performed by Certified Arborist or Certified Urban Forester.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.050. - Tree removal permit or tree pruning permit required.
No person shall remove or relocate a protected tree or develop within the protection zone of a
protected tree, or stand of trees identified as native oak or walnut woodland, without first obtaining a tree
removal permit from the director. No person shall prune a protected tree without first ob taining a tree
pruning permit from the director if branches are to be pruned that are over four inches in diameter at the
point of the cut. The maximum amount allowed for the pruning of a protected tree shall be 20 percent
over a one-year period, except for oak trees which shall be ten percent over a one-year period. SB 1334
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.060. - Exemptions.
The following shall be exempt from the provisions of this chapter:
(1) Trees, except those designated by the city council as a historical or cultural tree and trees
required to be preserved, relocated, or planted as a condition of approval of a discretionary
permit, located on all developed properties prior to adoption of this Development Code.
(2) Trees held for sale by licensed nurseries or tree farms or the removal or transplanting of trees
for the purpose of operating a nursery or tree farm.
(3) A tree that is so damaged, diseased or in danger of falling (as verified by an arborist) that it
cannot be effectively preserved, or its presence is a threat to other protected trees or existing or
proposed structures.
(4) Trees within public rights-of-way where their removal, pruning or relocation is necessary to
obtain adequate line-of-site distances or to keep streets and sidewalks clear of obstructions as
required by the city engineer.
(5) Trees that present a dangerous condition requiring emergency actio n to preserve the public
health, safety and welfare as determined by the director.
(6) The maintenance of trees that interfere with a public utility's ability to protect or maintain an
electric power or communication line, or other property of a public ut ility. Requiring utilities to
obtain an annual, revocable permit and conformance with ANSI A300 standards ensures good
working practices.
(7) The pruning of branches not to exceed four inches in diameter or compensatory pruning in
compliance with guidelines published by the National Arborists Association see above, intended
to ensure the continued health of a protected tree.
(8) Native oak, walnut, sycamore, willow, or pepper trees located upon a lot one -half acre or less
located on the flat pad, are exempted from these regulations. Trees over the ridgeline, growing
on the natural slope are not exempt.
Page 3
(9) Any native oak, walnut, sycamore, willow or naturalized California Pepper trees planted
subsequent to the subdivision of property of any size are exempted from these regulations.
(Ord. No. 02(1998), § 2, 11-3-98; Ord. No. 02(2003), 9-16-03)
Sec. 22.38.070. - Tree removal in conjunction with a discretionary permit.
When the removal or relocation of a protected tree is proposed in connection with a n application for
another discretionary permit, the director may waive the requirement of a separate tree removal permit
and require necessary information to be submitted as part of the discretionary permit application. All of
the standards of this chapter, including section 22.38.130 (Tree replacement/relocation standards) and
section 22.38.140 (Tree protection standards) shall apply to the approval of a discretionary permit.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.080. - Application submittal requirements.
(a) Applications for a tree removal permit or a tree pruning permit shall be filed with the department. The
department will consider an application complete when all necessary application forms, materials
and exhibits, as established by the department, have been provided and accepted as adequate and
all necessary fees have been paid.
(b) The director may require the submittal of an arborist report before accepting the application for filing.
Arborist reports shall be paid for by the applicant and may be required to include specific information
as required by the director. This information may include but is not limited to: The impact on existing
trees, the health and structural stability of existing trees and any remedial measures or mitigation
recommended.
Applications should contain at least a justification statement for the permit, signature of the property
owner, a tree site map containing the location of all trees located on the property including species
and DBH, and the protection zone of every protected tree. Applications can contain mitigation
information, or a separate mitigation report, including inspection requirements, can be prepared
separately.
(c) The director may require additional information when deemed necessary for permit proce ssing. Any
request for the removal or relocation of a protected tree proposed in conjunction with an application
for another discretionary permit shall be subject to approval by the same hearing body as the
discretionary permit.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.090. - Action on application.
An application for a tree removal permit or tree pruning permit shall be approved, conditionally
approved or denied by the director. Where the director finds that significant policy questions are at issue,
the director may refer the application to the commission for action. If an application is denied, the reasons
shall be provided to the applicant in writing.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.100. - Conditions of approval.
Page 4
In approving an application for a tree permit or tree pruning permit, the director or commission may
require the applicant to meet certain conditions in order to secure the purpose of this chapter. Conditions
may include, but are not limited to, measures designed to protect and preserve protected trees remaining
on the site and the restoration of protected trees removed from the site.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.110. - Findings for approval.
In order to approve an application for a tree removal permit or tree pruning permit, it shall be
necessary that one or more of the following findings be made, otherwise the application shall be denied:
(1) The tree is so poorly formed due to stunted growt h that its preservation would not result in any
substantial benefits to the community.
(2) The tree interferes with utility services, or streets and highways, either within or outside of the
subject property, and no reasonable alternative exists other than removal or pruning of the
tree(s).
(3) The tree is a potential public health and safety hazard due to the risk of it falling and its
structural instability cannot be remediated.
(4) The tree is a public nuisance by causing damage to improvements (e.g., building foundations,
retaining walls, roadways/driveways, patios, and decks).
(5) The tree is host to an organism which is parasitic to another species of tree which is in danger
of being exterminated by the parasite.
(6) The tree belongs to a species which is known to be a pyrophitic or highly flammable and has
been identified as a public safety hazard. Define pyrophytic or highly flammable standard and
who has authority to ID as a public safety hazard
(7) Preservation of the tree is not feasible and would compromise the property owner's reasonable
use and enjoyment of property or surrounding land and appropriate mitigation measures will be
implemented in compliance with section 22.38.130 (Tree replacement/relocation standards)
below.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.120. - Tagging.
In the process of preparing a tree report tree report not described or referenced anywhere else, each
tree is required to be physically marked for identification by consecutively numbered tags. The following
method of tagging shall be used to identify and locate applicable trees:
(1) A permanent tag, a minimum of two inches in length, shall be used for identifying applicable
trees. The tag shall be made from a noncorrosive, all-weather material and be permanently
attached to the tree in a manner preserving its health and viability.
(2) Tags shall be located on the north side of th e tree at a height of four and one-half feet above
natural grade.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.130. - Tree replacement/relocation standards.
Page 5
(a) Replacement trees shall be indigenous to the area whenever feasible as determined by an arbor ist.
Replacement trees should be same species as, or from list of, protected tree species
(b) Replacement trees shall be planted at a minimum 2:1 ratio for residential properties less than 20,000
square feet. Residential parcels greater than 20,000 square feet and commercial and industrial
properties shall be planted at a minimum 3:1 ratio. The director or commission may grant exceptions
to these requirements or may require additional replacement trees based on the following
considerations:
(1) The vegetative character of the subject property.
(2) The number of protected trees which are proposed to be removed in relation to the number of
protected trees currently existing on the subject property.
(3) The anticipated effectiveness of the replacement of tr ees, as determined by arborists' report
submitted by the applicant.
(c) Replacement trees shall be a minimum box size of 24 inches for six or fewer replacement trees. For
greater than six replacement trees, the sizes shall be determined by the director. S maller container
sizes may be approved by the director or commission when additional replacement trees are
provided significantly exceeding the required replacement ratios.
(d) Tree relocation or replacement shall be on the same site to the extent feasibl e. A written report by an
arborist is required concerning the methodology and feasibility of transplanting trees.
(e) Where site conditions preclude the long-term success of replacement trees, the director or
commission may require either or both of the following alternatives:
(1) Planting replacement trees on public property (e.g., designated open space areas or public
parks); and/or
(2) Monetary donation to a tree replacement fund in the amount equal to the value of required
replacement trees, and the cost of installation as established by an arborist's report.
(f) The applicant may be required as a condition of permit approval to enter into a tree maintenance
agreement prior to removal of any protected tree or commencement of construction activities t hat
may adversely affect the health and survival of trees to be preserved. The maintenance agreement
may include provisions for the submittal of arborist reports during and after construction activities,
installation of replacement trees and irrigation systems by or under the supervision of a certified
arborist, replacement of trees that die during or after construction phases, periodic fertilizing and
pruning, and submittal of a security deposit as may be necessary to ensure the health and survival of
the affected trees during the effective date of the tree maintenance agreement. The performance
security may be required for three years from the date of the approval or as determined by the
director. The amount of the performance security deposit shall be equal to 125 percent of the cost of
a nursery grown tree and installation by a qualified professional.
Any permit-required tree replacement should require planting of a protected tree species to ensure
protected status trees are maintained in perpetuity. Tree replacement or relocation whether on-site,
off-site, or on public property should require at least 3 years of maintenance to ensure successful
establishment, as well as enforcement of maintenance. Monetary donation to a tree replacement
fund should include the value of required replacement trees, the cost of installation, and the cost of
at least 3 years of maintenance.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.140. - Tree protection requirements.
The director shall determine during project review whether and to what extent measures will be
required to protect the existing trees during construction. This decision shall be based upon the proximity
Page 6
of the area of construction activity to existing prot ected trees. The protective measures shall include but
are not limited to the following:
(1) The existing trees to be retained shall be enclosed by chain link fencing with a minimum height
of five feet or by another protective barrier approved by the director prior to the issuance of a
grading or building permit and prior to commencement of work.
(2) Barriers shall be placed at least five feet outside the drip line of trees to be protected. A lesser
distance may be approved by the director if appropriate to the species and the adjacent
construction activity. The generally accepted distance of protection zones is 2-3x the width of
the dripline
(3) No grade changes shall be made within the protective barriers without prior approval by the
director. Where roots greater than one inch in diameter are damaged or exposed, the roots shall
be cleanly saw cut and covered with soil in conformance with industry standards.
(4) Excavation or landscape preparation within the protective barriers shall be limite d to the use of
hand tools and small hand-held power tools and shall not be of a depth that could cause root
damage.
(5) No attachments or wires other than those of a protective or nondamaging nature shall be
attached to a protected tree.
(6) No equipment or debris of any kind shall be placed within the protective barriers. No fuel, paint,
solvent, oil, thinner, asphalt, cement, grout or any other construction chemical shall be stored or
allowed in any manner to enter within the protected barrier.
(7) If access within the protection zone of a protected tree is required during the construction
process, the route shall be covered in a six -inch mulch bed in the drip line area and the area
shall be aerated and fertilized at the conclusion of the construction.
(8) When the existing grade around a protected tree is to be raised, drain tiles shall be laid over the
soil to drain liquids away from the trunk. The number of drains shall depend upon the soil
material. Lighter sandy soils and porous gravelly material require fewer drains than heavy
nonporous soils like clay. Dry wells shall be large enough to allow for maximum growth of the
tree trunk. Dry well walls shall be constructed of materials that permit passage of air and water.
(9) When the existing grade around a tree is to be lowered, either by terracing or a retaining wall, a
combination may be used to lower grade. With either method, the area within the drip line shall
be left at the original grade. The retaining wall shall be porous to allow for aeration .
(10) Trees that have been destroyed or that have received major damage during construction shall
be replaced prior to final inspection. Species damaged/destroyed should be replaced in kind
and include a 3-year maintenance period to ensure establishment. Include punishment for
destruction/damage as deterrence
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.150. - Post decision procedures.
(a) Appeals. Decisions of the director shall be considered final unless an appeal is filed in compliance
with chapter 22.74 (Appeals). The decision of the director may be appealed to the planning
commission. The decision of the commission may be appealed to the council.
(b) Expiration/extension. A tree removal permit or tree pruning permit shall be exercised within one ye ar
from the date of approval or other time frame that may be established with a discretionary permit
approval. Time extensions, for up to a total of two additional years, may be granted in compliance
with chapter 22.66 (Permit Implementation and Time Extensions). If a tree removal permit or tree
pruning permit is not exercised within the established time frame, and a time extension is not
granted, the provisions of chapter 22.66 (Permit Implementation and Time Extensions) shall apply.
Page 7
(c) Construction monitoring. Monitoring of tree protection and restoration measures specified as
conditions of approval shall be performed by site inspection conducted by the director, or by an
arborist.
(d) Revocation. A tree removal permit or tree pruning permit may be revoked or modified, in compliance
with chapter 22.76 (Revocations/Modifications), if it is found that the tree removal, relocation or
protection activities:
(1) Resulted from misrepresentation or fraud;
(2) Has not been implemented in a timely manner;
(3) Has not met, or has violated, any conditions of approval;
(4) Is in violation of any code, law, ordinance or statute;
(5) Is detrimental to public health, safety or welfare; or
(6) Constitutes a nuisance.
(e) Enforcement.
(1) Any person who cuts, damages, or moves a protected tree in violation of this chapter shall be
deemed guilty of an infraction or misdemeanor in compliance with section 22.78.060 (Legal
Remedies).
(2) Violation of this chapter during construction activity may result in an immediate stop -work order
issued by the city, until permits are obtained along with proper mitigation.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.160. - Tree replacement fund.
Moneys received by the city in lieu of replacement trees as provided for in section 22.38.130 (Tree
Replacement/Relocation Standards), or as civil penalties for violations of this chapter shall be deposited
in a tree replacement fund and the city's general fund, respectively. Funds collected by the city for the
tree replacement fund and interest earned thereon shall be used solely for the planting of trees or other
vegetation on publicly owned property. Tree replacement fund should be spent only on trees, not other
vegetation, and trees planted should be protected species
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.170. - Buyers awareness package.
When a project contains trees that have been protected or planted under the requirements of this
chapter, the developer shall provide buyers with information regarding the proper care of the t rees. The
information shall be specific to different tree species and include information on proper pruning
techniques, pest and disease control, fertilization requirements, watering needs, and other pertinent
information about the particular tree species.
(Ord. No. 02(1998), § 2, 11-3-98)
316 Monrovia Avenue Long Beach, CA 90803 562-477-2181 robb@hamiltonbiological.com
H AMILTON B IOLOGICAL
February 20, 2019
Greg Gubman
Director of Community Development
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
SUBJECT: PROPOSED AMENDMENTS TO
DIAMOND BAR TREE PROTECTION ORDINANCE
Dear Mr. Gubman,
A consortium of Diamond Bar residents retained Hamilton Biological, Inc., (hereafter
“Hamilton Biological”) to address a range of biological issues as the City of Diamond
Bar (hereafter the “City”) prepares to update its General Plan. This letter addresses per-
ceived inadequacies of the City’s Tree Preservation and Protection Ordinance (Chapter
22.38 of the City of Diamond Bar Code of Ordinances). Proposed changes refer to the
following areas of concern:
• Corrections of outdated references (e.g., the National Arborists Association no longer
exists, having been replaced by the Tree Care Industry Association) and typographical
errors.
• Changes to bring the City’s ordinance into alignment with current industry standards.
For example, the County of Los Angeles’ current Oak Woodlands Conservation Man-
agement Plan Guide1 requires seven years of maintenance and monitoring of all oak
mitigation plantings, which reflects the experience of the County that oak plantings may
survive for a few years after planting, only to fail shortly thereafter.
• Ensuring that funds paid to the City for tree planting are used to promptly replace im-
pacted trees, and to prevent against tree mitigation funds being diverted to other uses.
• Establishing a City-administered program to ensure that replacement trees are planted
in areas suited to their long-term survival, and not in sensitive habitat areas, such as
coastal sage scrub, where they could cause adverse ecological effects.
1 http://planning.lacounty.gov/assets/upl/project/oakwoodlands_conservation-management-plan-guide.pdf
Proposed Amendments to Diamond Bar Tree Preservation and Protection Ordinance Hamilton Biological, Inc.
February 20, 2019 Page 2 of 10
Proposed Amendments to the Tree Preservation & Protection Ordinance
The following amendments, identified in “track changes,” are proposed to Chapter
22.38 of the City of Diamond Bar Code of Ordinances. Sections not proposed for chang-
es are not reproduced herein.
Sec. 22.38.030. - Protected trees.
A protected tree is any of the following:
1. Native oOak, walnut, sycamore and willow trees with a diameter at 4.5 feet above mean
natural gradebreast height (DBH) of eight five inches or greater (consistent with Califor-
nia Public Resources Code 21083.4a);
2. (2) Trees of significant historical or value as designated by the council;
3. (3) Any tree required to be preserved or relocated as a condition of approval for a dis-
cretionary permit;
4. (4) Any tree required to be planted as a condition of approval f or a discretionary permit;
and
5. (5) A stand of trees, the nature of which makes each tree dependent upon the others for
survival.
(Ord. No. 02(1998), § 2, 11-3-98; Ord. No. 02(2003), 9-16-03; Ord. No. 04(2012), § 9, 4-17-12)
Sec. 22.38.040. - Damaging protected trees prohibited.
Except as provided in section 22.38.060 (Exemptions), no person shall cut, prune, re-
move, relocate, or otherwise destroy a protected tree.
All work must be performed by a Certified Arborist or Certified Urban Forester in
compliance with ANSI A300 standards. The topping of protected trees is prohibited. No
reduction of the tree crown shall be permitted without a tree pruning permit and then
only by “thinning out” selected.guidelines published by the National Arborists Associa-
tion.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.050. - Tree removal permit or tree pruning permit required.
No person shall remove or relocate a protected tree or develop within the protection
zone of a protected tree, or stand of trees comprising native oak woodland or walnut
woodland, without first obtaining a tree removal permit from the director. No person
shall prune a protected tree without first obtaining a tree pruning permit from the di-
rector if branches are to be pruned that are over four inches in diameter at the point of
the cut. The maximum amount allowed for the pruning of a protected tree shall be 20
percent over a one-year period, except for oak trees which shall be ten percent over a
one-year period.
(Ord. No. 02(1998), § 2, 11-3-98)
Proposed Amendments to Diamond Bar Tree Preservation and Protection Ordinance Hamilton Biological, Inc.
February 20, 2019 Page 3 of 10
Sec. 22.38.060. - Exemptions.
The following shall be exempt from the provisions of this chapter:
1. Trees, except those designated by the city council as a historical or cultural tree and
trees required to be preserved, relocated, or planted as a condition of approval of a dis-
cretionary permit, located on all developed properties prior to adoption of this Devel-
opment Code.
2. Trees held for sale by licensed nurseries or tree farms or the removal or transplanting of
trees for the purpose of operating a nursery or tree farm.
3. A tree that is so damaged, diseased or in danger of falling (as verified by a Certified Ar-
boristn arborist) that it cannot be effectively preserved, or its presence is a threat to
other protected trees or existing or proposed structures.
4. Trees within public rights-of-way where their removal, pruning or relocation is necessary
to obtain adequate line-of-site distances or to keep streets and sidewalks clear of ob-
structions as required by the city engineer.
5. Trees that present a dangerous condition requiring emergency action to preserve the
public health, safety and welfare as determined by the director.
6. The maintenance of trees that interfere with a public utility’s ability to protect or main-
tain an electric power or communication line, or other property of a public utility, so
long as the work conforms to ANSI A300 standards and the utilities obtain an annual,
revocable permit from the city.
7. The pruning of branches not to exceed four inches in diameter or compensatory prun-
ing, in compliance with ANSI A300 standards, intended to ensure the continued health
of a protected tree.
8. Native oak, walnut, sycamore, willow, or pepper trees located upon a lot one-half acre
or less located on the flat pad, are exempted from these regulations. Trees over the
ridgeline, growing on the natural slope are not exempt.
9. Any native oak, walnut, sycamore, willow or naturalized pepper trees planted subse-
quent to the subdivision of property of any size are exempted from these regulations.
(Ord. No. 02(1998), § 2, 11 -3-98; Ord. No. 02(2003), 9 -16-03)
Sec. 22.38.080. - Application submittal requirements.
(a) Applications for a tree removal permit or a tree pruning permit shall be
filed with the department. The department will consider an application
complete when all necessary application forms, materials and exhibits, as
established by the department, have been provided and accepted as ade-
quate and all necessary fees have been paid.
(b) The director may require the submittal of a Certified Arborist’sn arborist
report before accepting the application for filing. The Certified Arborist’s
reports shall be paid for by the applicant and may be required to include
Proposed Amendments to Diamond Bar Tree Preservation and Protection Ordinance Hamilton Biological, Inc.
February 20, 2019 Page 4 of 10
specific information as required by the director. This information may in-
clude but is not limited to: The impact on existing trees, the health and
structural stability of existing trees and any remedial measures or mitiga-
tion recommended.
(c) Applications shall contain a justification statement for the permit; signa-
ture of the property owner; and a site map containing the location of all
trees located on the property, including species and diameter 4.5 feet
above mean natural grade, and the protection zone of every protected
tree. Applications can contain mitigation information; alternatively, a sep-
arate mitigation report, including inspection requirements, can be pre-
pared separately.
(c)(d) The director may require additional information when deemed necessary
for permit processing. Any request for the removal or relocation of a pro-
tected tree proposed in conjunction with an application for another discre-
tionary permit shall be subject to approval by the same hearing body as
the discretionary permit.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.110. - Findings for approval.
In order to approve an application for a tree removal permit or tree pruning permit, it
shall be necessary that one or more of the following findings be made, otherwise the
application shall be denied:
The following shall be exempt from the provisions of this chapter:
1. The tree is so poorly formed due to stunted growth that its preservation would not re-
sult in any substantial benefits to the community.
2. The tree interferes with utility services, or streets and highways, either within or outside
of the subject property, and no reasonable alternative exists other than removal or
pruning of the tree(s).
3. The tree is a potential public health and safety hazard due to the risk of it falling and its
structural instability cannot be remediated.
4. The tree is a public nuisance by causing damage to improvements (e.g., building founda-
tions, retaining walls, roadways/driveways, patios, and decks).
5. The tree is host to an organism which is parasitic to another species of tree which is in
danger of being exterminated by the parasite.
6. The tree belongs to a species which is known to be a pyrophitic or highly flammable and
has been identified as a public safety hazard by a Certified Arborist or Certified Urban
Forester.
7. Preservation of the tree is not feasible and would compromise the property owner’s
reasonable use and enjoyment of property or surrounding land and appropriate mitiga-
Proposed Amendments to Diamond Bar Tree Preservation and Protection Ordinance Hamilton Biological, Inc.
February 20, 2019 Page 5 of 10
tion measures will be implemented in compliance with section 22.38.130 (Tree re-
placement/relocation standards) below.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.120. - Tagging.
In the process of preparing an application for a tree removal permit or tree report, each
tree is required to be physically marked for identification by consecutively numbered
tags. The following method of tagging shall be used to identify and locate applicable
trees:
1. A permanent tag, a minimum of two inches in length , shall be used for identifying appli-
cable trees. The tag shall be made from a noncorrosive, all-weather material and be
permanently attached to the tree in a manner preserving its health and viability.
2. Tags shall be located on the north side of the tree at a height of four and one-half4.5
feet above natural grade.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.130. - Tree replacement/relocation standards.
(a) Replacement trees shall be either the same species as that being replaced
or a indigenous to the area whenever feasible as determined by an arborist
protected tree species indigenous to Diamond Bar.
(b) Replacement trees shall be planted at a minimum 2:1 ratio for residential
properties less than 20,000 square feet. Residential parcels greater than
20,000 square feet and commercial and industrial properties shall be
planted at a minimum 3:1 ratio. The director or commission may grant ex-
ceptions to these requirements or may require additional replacement
trees based on the following considerations:
1. The vegetative character of the subject property.
2. The number of protected trees which are proposed to be removed in rela-
tion to the number of protected trees currently existing on the subject
property.
3. The anticipated effectiveness of the replacement of trees, as determined by
Certified Arborist’s arborists’ report submitted by the applicant.
(c) Replacement trees shall be a minimum box size of 24 inches for six or few-
er replacement trees. For greater than six replacement trees, the sizes shall
be determined by the director. Smaller container sizes may be approved
by the director or commission when additional replacement trees are pro-
vided significantly exceeding the required replacement ratios.
Proposed Amendments to Diamond Bar Tree Preservation and Protection Ordinance Hamilton Biological, Inc.
February 20, 2019 Page 6 of 10
(d) Tree relocation or replacement shall be on the same site to the extent feasi-
ble. A written report by an arborist is required concerning the methodolo-
gy and feasibility of transplanting trees.
(e) Where site conditions preclude the long-term success of replacement trees,
the director or commission may require either or both of the following al-
ternatives:
1. Planting replacement trees on public property (e.g., designated open space
areas or public parks); and/or
2. Payment of an iMonetary donationn-lieu fee to a tree replacement fund in
the amount equal to the value of required replacement trees, and the cost of
installation as established by an arborist’s report.into a city-administered
Tree Mitigation Program.
3. The city shall retain a qualified biologist and Certified Arborist or Certified
Urban Forester to establish a Tree Mitigation Program to ensure that re-
placement trees are planted on public property in areas that (a) shall not im-
pact any existing sensitive habitat areas; (b) are appropriate for the long-
term survival of native trees planted as mitigation; and (c) shall be main-
tained and preserved by the city, in perpetuity, as natural open space for the
mitigation trees and any associated understory species deemed appropriate
to provide valuable woodland habitat.
4. The in-lieu fee amount shall be determined by the city based upon the cost
of establishing and administering the above-referenced Tree Mitigation Pro-
gram.
5. The city shall demonstrate that all tree replacement plantings take place
within one year (365 days) of tree removal.
(f) The applicant may be required as a condition of permit approval to enter
into a tree maintenance agreement prior to removal of any protected tree
or commencement of construction activities that may adversely affect the
health and survival of trees to be preserved. The maintenance agreement
may include provisions for the submittal of arborist’s reports during and
after construction activities, installation of replacement trees and irrigation
systems by or under the supervision of a certified arborist, replacement of
trees that die during or after construction phases, periodic fertilizing and
pruning, and submittal of a security deposit as may be necessary to ensure
the health and survival of the affected trees during the effective date of the
tree maintenance agreement. The performance security may shall be re-
quired for a minimum of three seven years from the date of the approval
or as determined by the director. The amount of the performance security
deposit shall be equal to 125 percent of the cost of a nursery grown tree
and installation by a qualified professional.
Proposed Amendments to Diamond Bar Tree Preservation and Protection Ordinance Hamilton Biological, Inc.
February 20, 2019 Page 7 of 10
(Ord. No. 02(1998), § 2, 11-3-98)
Proposed Amendments to Diamond Bar Tree Preservation and Protection Ordinance Hamilton Biological, Inc.
February 20, 2019 Page 8 of 10
Sec. 22.38.140. - Tree protection requirements.
The director shall determine during project review whether and to what extent
measures will be required to protect the existing trees during construction. This deci-
sion shall be based upon the proximity of the area of construction activity to existing
protected trees. The protective measures shall include but are not limited to the follow-
ing:
1. The existing trees to be retained shall be enclosed by chain link fencing with a minimum
height of five feet or by another protective barrier approved by the director prior to the
issuance of a grading or building permit and prior to commencement of work.
2. Barriers shall be placed at least five ten feet outside the drip line of trees to be protect-
ed. A lesser distance may be approved by the director if appropriate to the species and
the adjacent construction activity, and if all appropriate measures are taken to minimize
potential impacts (e.g., use of steel plates over a mulch base to reduce soil compaction
in the critical root zone).
3. No grade changes shall be made within the protective barriers without prior approval by
the director. Where roots greater than one inch in diameter are damaged or exposed,
the roots shall be cleanly saw cut and covered with soil in conformance with industry
standards.
4. Excavation or landscape preparation within the protective barriers shall be limited to
the use of hand tools and small hand-held power tools and shall not be of a depth that
could cause root damage.
5. No attachments or wires other than those of a protective or nondamaging nature shall
be attached to a protected tree.
6. No equipment or debris of any kind shall be placed within the protective barriers. No
fuel, paint, solvent, oil, thinner, asphalt, cement, grout or any other construction chemi-
cal shall be stored or allowed in any manner to enter within the protected barrier.
7. If access within the protection zone of a protected tree is required during the construc-
tion process, the route shall be covered in a six-inch mulch bed in the drip line area and
the area shall be aerated and fertilized at the conclusion of the construction.
8. When the existing grade around a protected tree is to be raised, drain tiles shall be laid
over the soil to drain liquids away from the trunk. The number of drains shall depend
upon the soil material. Lighter sandy soils and porous gravelly material require fewer
drains than heavy nonporous soils like clay. Dry wells shall be large enough to allow for
maximum growth of the tree trunk. Dry well walls shall be constructed of materials that
permit passage of air and water.
9. When the existing grade around a tree is to be lowered, either by terracing or a retain-
ing wall, a combination may be used to lower grade. With either method, the area with-
in the drip line shall be left at the original grade. The retaining wall shall be porous to al-
low for aeration.
Proposed Amendments to Diamond Bar Tree Preservation and Protection Ordinance Hamilton Biological, Inc.
February 20, 2019 Page 9 of 10
10. Trees that have been destroyed or that have received major damage during construc-
tion shall be replaced prior to final inspection. Any trees damaged or destroyed shall be
replaced in kind, and a 7-year maintenance period shall be required to ensure estab-
lishment.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.150. - Post decision procedures.
(a) Appeals. Decisions of the director shall be considered final unless an ap-
peal is filed in compliance with chapter 22.74 (Appeals). The decision of
the director may be appealed to the planning commission. The decision of
the commission may be appealed to the council.
(b) Expiration/extension. A tree removal permit or tree pruning permit shall be
exercised within one year from the date of approval or other time frame
that may be established with a discretionary permit approval. Time exten-
sions, for up to a total of two additional years, may be granted in compli-
ance with chapter 22.66 (Permit Implementation and Time Extensions). If
a tree removal permit or tree pruning permit is not exercised within the
established time frame, and a time extension is not granted, the provisions
of chapter 22.66 (Permit Implementation and Time Extensions) shall ap-
ply.
(c) Construction monitoring. Monitoring of tree protection and restoration
measures specified as conditions of approval shall be performed by site
inspection conducted by the director, or by an arborista Certified Arborist
or Certified Urban Forester .
(d) Revocation. A tree removal permit or tree pruning permit may be revoked
or modified, in compliance with chapter 22.76 (Revoca-
tions/Modifications), if it is found that the tree removal, relocation or pro-
tection activities:
1. Resulted from misrepresentation or fraud;
2. Has Have not been implemented in a timely manner;
3. Has Have not met, or has violated, any conditions of approval;
4. Is Are in violation of any code, law, ordinance or statute;
5. Is Are detrimental to public health, safety or welfare; or
6. Constitutes a nuisance.
Proposed Amendments to Diamond Bar Tree Preservation and Protection Ordinance Hamilton Biological, Inc.
February 20, 2019 Page 10 of 10
(e) Enforcement.
1. Any person who cuts, damages, or moves a protected tree in violation of this
chapter shall be deemed guilty of an infraction or misdemeanor in compli-
ance with section 22.78.060 (Legal Remedies).
2. Violation of this chapter during construction activity ma y result in an imme-
diate stop-work order issued by the city, until permits are obtained along
with proper mitigation.
(Ord. No. 02(1998), § 2, 11-3-98)
Sec. 22.38.160. - Tree replacement fund.
Moneys received by the city in lieu of replacement trees as provided for in section
22.38.130 (Tree Replacement/Relocation Standards), or as civil penalties for violations
of this chapter shall be deposited in a tree replacement fund and the city’s general fund,
respectively. Funds collected by the city for the tree replacement fund and interest
earned thereon shall be used solely for the planting of trees or other vegetation on pub-
licly owned property, under the auspices of the Tree Mitigation Program provided for
in section 22.38.130(e).
(Ord. No. 02(1998), § 2, 11-3-98)
CONCLUSION
Hamilton Biological appreciates the opportunity to propose amendments to the Dia-
mond Bar Tree Preservation and Protection Ordinance. If you have questions, please
call me at (562) 477-2181 or send e-mail to robb@hamiltonbiological.com.
Sincerely,
Robert A. Hamilton
President, Hamilton Biological, Inc.
316 Monrovia Avenue
Long Beach, CA 90803
562-477-2181
robb@hamiltonbiological.com
263A 342B
341F
341D
M261E
M261A
M261D
M261B
M261G
M261C M261F
262A
M262B
M262A
322A
322B
322C
261B
261A
USDA Ecoregion ProvincesUSDA Ecoregion Sections
Ecological Sections of California
California Coastal C haparral Forest and Shrub261A: Central California Coast
261B: Southern California Coast
California Coastal R ange Shrub - Forest - MeadowM262A: C entral California Coast Ranges
M262B: Southern California Mountains and Valleys
California Coastal Steppe - Mixed Forest - Redwood Forest263A: Northern C alifornia Coast
Sierran Forest - A lpine MeadowsM261A: K lamath Mountains
M261B: N orthern California C oast Ranges
M261C: N orthern California Interior Coast Ranges
M261D: Southern Cascades
M261E: Sierra Nevada
M261F: Sierra Nevada Foothills
M261G: Modoc Plateau
American Semi-Desert and Desert322A: Mojave Desert
322B: Sonoran Desert
322C: Colorado Desert
Intermountain Semi-Desert and Desert341D: Mono
341F: Southeastern Great Basin
Intermountain Semi-Desert342B: Northwestern Basin and Range
California Dr y Steppe262A: Great Valley
Oct. 31, 2019
Comments for the City of Diamond Bar General Plan 2040, DEIR
To: Grace Lee, City Senior Planner
Dear Ms. Lee:
It is good to see the City of Diamond Bar finally acknowledge in the general plan and EIR,
the rare and sensitive species and natural communities, we are privileged to have here.
The Diamond Bar – Pomona Valley Sierra Club is a local conservation group. Our work
involves exploring, enjoying and protecting wildlife habitats and ecosystems in our city
and the surrounding areas. Our “community science” activities have come up with
some exciting findings.
Since the Diamond Bar – Pomona Valley Sierra Club has been working on an on-going
“Diamond Bar Natural History” project these past three years, I submit some of our
findings – which has been and is being mapped on iNaturalist, eBird and the CNDDB.
We are also communicating with the Los Angeles Natural History Museum staff in
assisting to map our findings of the rare and critically imperiled Los Angeles County
Shouldband snail, which has been found distributed throughout Diamond Bar.
My overall comments about the draft environmental report are concerned with the
missing bits of important biotic information, as well as the incomplete or incorrect
information in mitigation plans or reported species.
Here is a list of my questions and concerns:
Cultural Findings, page 45-52, Resource Conservation Chpt. 5
1. The DEIR does not mention the (approximate) 40 boxes of stone artifacts recovered
at the Pulte Home development project (gated community, located off Crest View and
Diamond Bar Blvd.) in 2006. Our group spoke with Dr. Beardsley and curator, Anne
Collier at University of La Verne, where the findings are stored, in 2017.
Q: Why are these findings missing from pg. 49’s chart? Will the City of Diamond Bar
correct this omission? What will the city do to restore these findings to the city’s
historical society and rightly honor the Kizh Nation?
2. The south end of the city at the “Cathay View” development, a registered “sacred
Kizh oak woodland” land was officially registered June 13, 2017: N-CAN 33. Q: Why is
this listing missing from the Cultural Resources, Resource Conservation, chapter 5, page
49 chart?
Vegetation Communities: Figure 5.2
3. Oak woodland natural communities are under reported in the DEIR habitat map. At
least the designation ought to be: southern oak/walnut woodland. California walnut
trees are not dominant throughout the city. Please view my pictures of Steep Canyon,
Sycamore Canyon and show me where the walnut trees are the dominant species.
(posted in the following natural history draft report I submit here.)
4. Opuntia litoralis, cactus scrub is not named in the DEIR, though it is a dedicated
alliance in the Manuel of California Vegetation, second edition, Sawyer, Keeler-Wolf,
Evans.
https://calscape.org/Opuntia-littoralis-(Coast-Prickly-Pear)?srchcr=sc5708872f8cdd6
Diamond Bar has dominant patches of this natural community distributed throughout
onDEIR? Will the city correct the omission?
5. Sycamore Canyon Park is designated by the USGS as a “sycamore riparian” habitat
due to Diamond Bar Creek passing through it from Steep Canyon. Q: Why is Sycamore
Canyon Park colored yellow/walnut woodland, with non-native grasses? See the picture
attached and explain how the city came up with such an incorrect report.
Wildlife Circulation/Corridor Activity
6. Deer, coyote, bobcat and cougar have been regularly sighted, circulating throughout
Diamond Bar. The northern areas (see Hamilton Report map, area #3 especially.)
Mountain lion was encountered at city hall in 2013, routine resident sightings in The DB
Country Estates, and a recent report from a hiker near Tres Hermanos/Phillips Ranch
area, 2019. Residents in area #3, Hamilton report map, have observed regular visits of
deer families, circulating throughout this green area, comprised of grassland,
oak/walnut woodland and coastal scrub. The deer travel in and round Pantera Park,
Steep Canyon, Sycamore Canyon and Summitridge trail, and frequently observed
browsing on the side of Diamond Bar Blvd., near Crest View and Gold Rush avenues.
(see photos in my gallery).
Q: What support will the city lend to the wildlife circulation WITHIN the city
neighborhoods? Q: Why is there no mention of wildlife circulation in the mid-northern
portions? Has the city considered the Hamilton report’s wildlife corridor map?
7. Sensitive species like California Gnatcatcher, burrowing owl, golden eagle, red
rattlesnake, cactus wren are observed throughout the trail and wildland areas in the
city. I have personally observed the gnatcatcher in Steep Canyon area (see pic.) Hikers
and residents regularly contact our Sierra Club with their pictures and reports. One hiker
submitted a photo of a burrowing owl located near a Diamond Bar trail. (see pic.)
Q: Why is the information incomplete in the Resource Conservation and DEIR
document? What effort will the city do to officially report the presence of these species
to state conservation trustee agencies like the CDFW and USFWS?
Q: Why does Figure 5.2 use the term “vegetation communities”? The official term used
by the California Vegetation text book, is “natural communities”, indicating natural
ecosystems – not supported by man-made interventions like automated irrigation,
fertilizer, pesticides, tilling or discing. Q: Will the city correct the misleading term,
“vegetation” communities?
Specific Details and a Program EIR
In summary, the general plan and DEIR explains it is a general assessment and not
specific, promising that each future development project will examine biological
resources in detail. Yet, it also mentions during the detailed survey of a project, it is
allowed to depend on the general plan/EIR. Does this mean there is a loop hole in
performing CDFW protocol surveys for projects in the “wild edge” or other sensitive
ecological areas? How will mitigation monitoring be handled? Will the Public be
apprised of who are the monitors and how monitoring procedures are implemented?
Q: How can accurate surveys and conservation be accomplished of the DEIR is vague
and general, then promises specific assessments be accomplished in future
developments if at the core, there are no specific declarations like “Diamond Bar Creek
traversing Sycamore Canyon Park”?
Thank you for reading and answering my questions. The attached “Diamond Bar Natural
History” project gallery is one of my on-going tasks. Please notice, pictures of resident’s
input are included, as our Sierra Club helps to explore and help local wildlife and
encourage residents to follow city wildlife interaction guidelines.
My references follow.
Thank you.
Diego Tamayo, Diamond Bar student, resident, Youth Field Intern/Sierra Club
Email: diegonaturalist@gmail.com
References:
Hamilton Biological Report, City of Diamond Bar; Natural Communities Map 2019
California Vegetation Manual www.veg.cnps.org
L.A. County Oak Woodland Conservation Plan Guide
http://planning.lacounty.gov/assets/upl/project/oakwoodlands_conservation-
management-plan-guide.pdf
#230
| diegonaturalist@gmail.com
ANGELES CHAPTER
The Diamond Bar – Pomona Valley Sierra Club Task ForceBioBlitz! Eco-education Trail Hike, Summitridge Trail May 2018
L.A. County Biologist, Joe DecruyenaereBiologist, Dan Cooper Teach Interested Hikers Biodiversity in Diamond Bar
Black Chinned HummingbirdDB resident R. Cortez
KestrelDB resident R. Martin
Checkerspot ButterflySummitridge Trail
Shoulderband SnailSycamore Canyon Park
White Tailed Mule DeerOpuntia scrub, Steep Canyon
Gold Rush Ave + Diamond Bar Blvd.
California Gnatcatcher, Steep CanyonD. Tamayo
Burrowing Owl 2017Ridge Trail Hiker J. Goldman
Golden Eagle, Tres Hermanos/DBD. Cooper
Dusky Wood Rat Nest, Steep CanyonD. Tamayo
Bats in Diamond Bar!Resident V. Young + R. Smith
Steep Canyon, Oak, Sycamore, Willow RiparianDiamond Bar Creek in Sycamore Canyon Park
Black Face SnakeSycamore Canyon Park
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Biological Resources Report
City of Diamond Bar
“This work is dedicated to the City of Diamond Bar, to its
residents --- especially the children.”
Dedicated & Funded by a consortium of Diamond Bar residents and:
Cover Photo by Diamond Bar Resident, Eraina Olson, 2019.
Photos for Resource Protection Recommendations, by Robert Hamilton 2019.
February, 2019
Biological Resources Report
City of Diamond Bar
Prepared By
Hamilton Biological, Inc.
Robert A. Hamilton, President
316 Monrovia Avenue
Long Beach, CA 90803
http://hamiltonbiological.com
February 25, 2019
TABLE OF CONTENTS
TABLE OF CONTENTS .................................................................................. II
INTRODUCTION .......................................................................................... 1
METHODS & TECHNICAL INFORMATION ........................................................... 2
VISIONS, GOALS, OBJECTIVES .......................................................................... 2
HISTORY & LAND USE ................................................................................... 5
SCENIC RESOURCES ....................................................................................... 5
HYDROLOGY/WATERWAYS ........................................................................ 6
DIAMOND BAR WATERSHEDS ......................................................................... 8
FLOODING ................................................................................................... 9
BIOLOGICAL RESOURCES ........................................................................... 9
NATURAL COMMUNITIES ................................................................................ 9
Annual and Perennial Grasslands, Vernal Pools/Seasonal Pools ............ 10
Coastal Sage Scrub, Cactus Scrub .......................................................... 10
Chaparral .............................................................................................. 11
Coast Live Oak Woodland, Savannah ................................................... 11
California Walnut Woodland, Savannah ............................................... 11
Riparian Scrub and Woodlands ............................................................. 12
Human-altered Habitats ........................................................................ 12
NATURAL OPEN SPACE AREAS ....................................................................... 12
RESOURCE PROTECTION RECOMMENDATIONS ................................................. 17
SENSITIVE RESOURCES .................................................................................. 19
Sensitive Natural Communities ............................................................. 20
Special-Status Species ........................................................................... 20
EFFECTS OF DEVELOPMENT ON BIOLOGICAL RESOURCES .................... 29
EDGE/FRAGMENTATION EFFECTS ON WILDLIFE MOVEMENT ............................... 30
Wildlife Movement Issues in the Puente-Chino Hills ............................. 30
NATURAL RESOURCE CONSERVATION POLICIES .................................... 32
GOALS AND POLICIES OF THE OPEN SPACE AND CONSERVATION ELEMENT ........... 32
LITERATURE CITED .................................................................................... 34
III
FIGURES
1: Waterways ............................................................................................. 6
2: Lower San Gabriel River Watershed ....................................................... 7
3a: Natural Open Space Areas, Part 1 ........................................................ 13
3b: Natural Open Space Areas, Part 2 ........................................................ 14
3c: Natural Open Space Areas, Part 3 ........................................................ 15
3d: Natural Open Space Areas, Part 4 ........................................................ 16
TABLES
A: Resource Protection Recommendations ................................................ 17
B: Special Status Species ........................................................................... 22
APPENDICES
A: Methods & Technical Information
1
INTRODUCTION
Hamilton Biological, Inc., was retained by a consortium of Diamond Bar residents to
prepare this biological resources report addressing the conservation and preservation of
sensitive biological resources in the City of Diamond Bar (City) and its Sphere of
Influence. It is intended that the City incorporate the information and analyses in this
report into the next update of its general plan, currently in preparation.
Sections 65302(d) and 65302(e) of the California Government Code states that a city’s
general plan shall include goals and policies for management of open spaces, including
natural lands and recreation areas. The Open Space Element addresses such categories
as preservation of natural resources and managed production of resources. The
Conservation Element addresses protection and maintenance of natural resources,
including soils, water, plants, wildlife, and mineral resources. Recognizing that the
subjects covered under the Open Space Element and Conservation Element
substantially overlap, Appendix 1 to the California Government Code allows these two
elements to be combined in one section of the General Plan.
The Open Space and Conservation Element identifies and describes the irreplaceable
biotic resources that make up the natural environment that people rely upon for
breathable air, clean water, viable populations of native plants and wildlife, and the
natural beauty that pervades and defines Diamond Bar. The Open Space and
Conservation Element guides city decision-makers and the public in their efforts to take
the natural world into account during deliberations over development proposals, as
required to realize the overall vision laid out in the General Plan.
The Open Space and Conservation Element guides the development and
implementation of programs involving conservation of open space, biological
resources, visual resources, and parks and recreation. Approaches for managing
environmental impacts are identified, with particular emphasis on contributing to
achievement of the General Plan’s stated goals, including:
• Create and retain an open space system which will conserve natural resources,
preserve scenic beauty, promote a healthy community atmosphere, provide open
space for outdoor recreation, and protect the public safety.
• Identify limits on the natural resources needed to support urban and rural
development within the City and its Sphere of Influence, and ensure that those
resources are used wisely and not abused.
• Provide a park, recreation and open space system which enhances the livability of
urban and suburban areas by providing parks for residential neighborhoods;
preserving significant natural, scenic, and other open space resources; and meeting
the open space and recreational needs of Diamond Bar residents.
2
Methods & Technical Information
Please refer to Appendix A, which describes the methods for preparing this biological
resources report, as well as providing technical information that underpins the
analyses, conclusions, and policies contained herein.
Visions, Goals, Objectives
The General Plan identifies “a strongly held goal among the residents to maintain and
protect the distinctive physical attributes of Diamond Bar which make it a desirable
place in which to live.” To achieve this overarching goal of safeguarding open spaces
and significant natural features, as well as retaining the City’s distinctive natural
character, the Open Space and Conservation Element focuses on supporting the
following visions, goals and objectives, building upon language contained in the
original 1995 General Plan:
• Vision 1. Retention of the rural/country living community character. There is a
strong, long-held goal among residents to maintain and protect the distinctive,
physical attributes of Diamond Bar which make it a desirable place in which to live,
through a careful balance of housing, businesses and services, public facilities, and
preservation of natural environmental resources.
• Vision 2. Preservation of open space. Significant privately and publicly owned
natural lands that remain in Diamond Bar and its 3,591-acre Sphere of Influence
support numerous rare species and perform important ecological functions. The
preservation of sensitive natural resources contributes to the goal of retaining the
City’s distinctive rustic character and offers unique educational and recreational
opportunities. The County of Los Angeles has identified the Sphere of Influence and
adjacent lands, some of which lie within the City, as Significant Ecological Area
(SEA) 15. SEA 15 is recognized as a major significant ecological asset to the
community. The City will play a proactive role in the preservation of SEA 15 by
assuring that extensive analysis and review precede any changes from its current
uses and possibilities.
o Goal 1. Consistent with the Vision Statement, maintain a mix of land uses
which enhance the quality of life of Diamond Bar residents, providing a
balance of development and preservation of significant open space areas to
assure both economic viability and retention of distinctive natural features of
the community.
§ Objective 1.1 Establish a land use classification system to guide the
public and private use of land within the City and its Sphere of
Influence.
§ Objective 1.2 Preserve and maintain the quality of existing residential
neighborhoods while offering a variety of housing opportunities,
including mixed land uses.
3
§ Objective 1.3 Designate adequate land for retail and service
commercial, professional services, and other revenue generating uses
in sufficient quantity to meet the City’s needs.
§ Objective 1.4 Designate adequate land for educational, cultural,
recreational, and public service activities to meet the needs of
Diamond Bar residents.
§ Objective 1.5 Maintain a feeling of open space within the community
by identifying and preserving an adequate amount of open land.
§ Objective 1.6 Consistent with the Vision Statement, provide flexibility
in the planning of new development as a means of encouraging
superior land use by means such as open space and public amenities.
o Goal 2. Consistent with the Vision Statement, manage land use with respect
to the location, density and intensity, and quality of development. Maintain
consistency with the capabilities of the City and special districts to provide
essential services which achieve sustainable use of environmental and
manmade resources.
§ Objective 2.1 Promote land use patterns and intensities which are
consistent with the Resource Management Element and Circulation
Element.
§ Objective 2.2 Maintain an organized pattern of land use which
minimizes conflicts between adjacent land uses.
§ Objective 2.3 Ensure that future development occurs only when
consistent with the availability and adequacy of public services and
facilities.
o Goal 3. Consistent with the Vision Statement, maintain recognition within
Diamond Bar and the surrounding region as being a community with a well-
planned and aesthetically pleasing physical environment.
§ Objective 3.1 Create visual points of interest as a means of highlighting
community identity.
§ Objective 3.2 Ensure that new development, and intensification of
existing development, yields a pleasant living, working, or shopping
environment, and attracts interest of residents, workers, shoppers, and
visitors as the result of consistent exemplary design.
§ Objective 3.3 Protect the visual quality and character of remaining
natural areas, and ensure that hillside development does not create
unsafe conditions.
4
o Goal 4. Consistent with the Vision Statement, encourage long-term and
regional perspectives in local land use decisions, but not at the expense of
the Quality of Life for Diamond Bar residents.
§ Objective 4.1 Promote and cooperate in efforts to provide reasonable
regional land use and transportation/circulation planning programs.
o Goal 5. Consistent with the Vision Statement, recognize that oak trees, oak
woodlands, and associated habitats have intrinsic aesthetic, environmental,
ecological, wildlife, and economic values; that conservation of oak-
dominated landscapes is important to the health, safety and general welfare
of the citizens of Diamond Bar1; that that the General Plan must contain
adequate policies to protect the oak habitats from unnecessary damage,
removal or destruction; that native oak trees should be planted, where
appropriate, to enhance or restore damaged or degraded oak woodland
habitats and mitigate unavoidable losses.
§ Objective 5.1 Protect and extend the diversity of oak woodlands and
associated habitats (defined as lands on which the majority of the trees
are of the genus Quercus) through site design and land use regulations.
§ Objective 5.2 Reduce in scale, redesign, modify, or if no other
alternative exists, deny any project which cannot sufficiently mitigate
significant adverse impacts to oak woodlands.
§ Objective 5.3 Encourage property owners to establish Open Space
Easements or deed restrictions for areas containing oak woodlands, and
to allow access to enable scientific study.
§ Objective 5.4 Encourage concentration of development on minimum
number of acres (density exemptions) in exchange for maximizing long
term open space.
§ Objective 5.5 As a mitigation option, allow as a condition of
development approval, restoration of any area of oak woodland that is
in a degraded condition, with the magnitude of restoration to be
commensurate with the scope of the project. This may include planting
of oak trees and removal of non-native species, with consideration for
long-term viability, management, and protection, and/or modification
of existing land uses. The object of habitat restoration shall be to
enhance the ecological function of the oak woodland and to restore it
to a condition where it can be self-sustaining through natural
occurrences such as fire, natural hydrological processes, etc.
1 Woodlands are defined as lands with tree cover of at least 10%, and oak woodlands exist where the
majority of trees are of the genus Quercus.
5
History & Land Use
Set within the Puente Hills of southeastern Los Angeles County, the City of Diamond
Bar covers 14.9 square miles. Neighboring cities include Walnut, Pomona, Industry, La
Puente, Rowland Heights, Brea, and Chino Hills. The region now occupied by Diamond
Bar was inhabited by the Kizh people until the mid-eighteenth century, when the
Spaniards settled in the area, establishing Mission San Gabriel in 1771 (City of Diamond
Bar and Diamond Bar Historical Society 2014; Housing element 2014). The land
experienced a series of ownership changes involving various land grants and purchases
(e.g., the Los Nogales Grant; purchases by Luz Linares, Vejar and Palomares, Louis
Phillip, Frederick E. Lewis II, William Bartholome), eventually growing into one of the
largest and respected ranches in southern California and gaining its name. This lasted
until 1956, during which two subsidiaries of Transamerica Corporation (Christiana Oil
Corp and the Capital Oil Company) purchased the area, aiming to make it among the
first and largest master-planned community in Los Angeles County (City of Diamond
and Diamond Bar Historical Society 2014).
Despite initial intentions as a “master-planned” community, uncoordinated patterns of
development through the late twentieth century have introduced areas of incongruence,
such as single- and detached multi-family residential tracts being established alongside
limited commercial and other non-residential sections. Most suburban construction was
already established prior to the city’s incorporation in 1989, and commercial
development has continued expand within the city limit. A few blocks away from the
primary arterials (57 and 60 Freeways) the majority of retail and housing space is
largely concealed by the natural topography, contributing to Diamond Bar’s quiet,
semi-rural character and pleasant atmosphere.
Scenic Resources
Today, Diamond Bar is primarily a hillside residential community, composed of steep
and moderate sloping hills separated by ridges and flat plateaus. Although most of the
land was developed prior to the city’s incorporation, its remaining natural hillsides and
ridgelines provide a picturesque backdrop and strong visual ties to the area’s long
history of ranching. The views from these natural areas comprise powerful and
valuable scenic resources, adding ambiance and aesthetics that give Diamond Bar a
unique and compelling visual identity. In addition, views of trees, rolling hills and the
pine- and often snow-covered peaks of the San Gabriel Mountains are visible in the
distance from the 57 and 60 Freeways.
Planning decisions must recognize the existing aesthetic value of the city’s open space
as well as the external viewsheds of the surrounding region. These include the oak and
walnut wooded ridgelines, unique topography, and natural open spaces at the edges of
the community.
6
HYDROLOGY/WATERWAYS
Diamond Bar lies within of the San Gabriel River watershed, which is the largest
watershed in the drainage system of the San Gabriel Mountains at 441,000 acres (Lower
San Gabriel River Watershed Group 2015). The San Gabriel River is one of seven major
watersheds partly or completely within Los Angeles County. Most of the river lies in
southeastern Los Angeles County, but a portion of this watershed originates in northern
Orange County. The northern portion of the San Gabriel River, where it emerges from
the mountains, has retained some natural features, such as a sandy bottom and native
vegetation. Farther south, however, flood-control and channel stabilization measures
needed to accommodate intensive urbanization led to the river being lined with
concrete (US Army Corps of Engineers 1991; Neal 2011).
Water runs through Diamond Bar via numerous channels, creeks and canyons. A small
part of the northwestern part of the city drains to the San Gabriel River via the San Jose
Creek channel, which follows the route of Valley Boulevard west from Diamond Bar.
Most of Diamond Bar drains south to the San Gabriel River through the Coyote Creek
watershed (see Figure 1).
Figure 1, Waterways. Diamond Bar lies mostly within the watershed of Coyote Creek, but the northwestern
part of the city discharges to the west, through the San Jose Creek channel.
Source: National Hydrology Dataset. http://www.horizon-systems.com/nhdplus/NHDPlusV1download.php
7
Coyote Creek and San Jose Creek drain approximately 165 square miles and 83 square
miles, respectively, of highly urbanized commercial, residential, and industrial zones,
plus limited natural open space areas (Sheng & Wilson 2000, using Horton–Strahler
Stream Order).
In 2013, Diamond Bar joined 12 other cities and the Los Angeles County Flood Control
District to develop a Watershed Monitoring Program (WMP) and Coordinated
Integrated Monitoring Program (CIMP) to address the lower portion of the San Gabriel
River, which includes Reaches 1 and 2 of the San Gabriel River Watershed and portions
of Coyote Creek that originate from jurisdictions within Los Angeles County, including
the City of Diamond Bar. A small portion of Diamond Bar that discharges to the San
Gabriel River via San Jose Creek is also addressed by this CIMP. See Figure 2, below.
Figure 2, Lower San Gabriel River Watershed. Diamond Bar occupies the most northeasterly part of the
Lower San Gabriel River Coordinated Integrated Monitoring Program.
Source: Gateway Water Management Authority. https://gatewaywater.org/services/lsgr/
8
Diamond Bar Watersheds
Diamond Bar is served by four watersheds, all with some channelization/urbanization:
Tonner Canyon Creek, Diamond Bar Creek, Brea Canyon Creek, and San Jose Creek.
Each system supports riparian habitat that provides resources for protected/special-
status species. The following discussions describe each of these four drainage systems.
1. Tonner Canyon
With a watershed of 5,000 acres and very little development, Tonner Canyon ranks
among the most ecologically significant, unchannelized, largely undisturbed drainages
in the Los Angeles area (HFE 2018). Occupying parts of Los Angeles, San Bernardino
and Orange Counties, Tonner Canyon drains the southeastern side of Diamond Bar and
the northwestern side of the City of Chino Hills. The flow rate, controlled by natural
rills, gullies and washes, varies throughout the year. The canyon’s headwaters lie in a
bowl of low hills just south of Diamond Ranch High School. Roughly 1.4 miles
downstream, Grand Avenue cuts across the watershed, and just downstream from that
road crossing lies the small Arnold Reservoir. Below the reservoir’s dam, water flows
southwest through natural open space lands the City of Industry has purchased from
the Boy Scouts of America in recent years. After flowing for approximately a mile
through open, rolling hills, the creek then enters a narrower canyon, with steeper hills
on either side. At that point, the willow-, sycamore-, and oak-dominated riparian
vegetation becomes more developed. The creek flows another six miles south and west
to empty into Brea Creek, located near the 57 Freeway in the Coyote Creek drainage
basin of Orange County.
2. Diamond Bar Creek
Originating in the neighborhoods west of Diamond Ranch High School, Diamond Bar
Creek runs approximately 1.2 miles to the west, through Sycamore Canyon Park, and
then continues west of Golden Springs Road through Diamond Bar Golf Course, and
from there underneath the 57 and 60 Freeways, to a channel east of the freeway that is
tributary to San Jose Creek. The upper segment, from Leyland Drive through the
Sycamore Canyon Park, supports well-developed native sycamore/oak/willow
riparian woodlands. The segment passing through Diamond Bar Golf Course supports
broken, partially native riparian habitat.
3. Brea Canyon Creek
The southwestern part of Diamond Bar, including the “Brea Canyons” neighborhood
east of the 57 Freeway, drains south toward Coyote Creek via Brea Canyon Creek. Most
of this watershed is fully developed within the limits of Diamond Bar, but the
southernmost portion, near the terminus of Castle Rock Road, is a soft-bottomed
perennial creek that supports riparian vegetation.
9
4. San Jose Creek – South Branch/Fork
Located at Diamond Bar’s northwestern edge, the southern branch of San Jose Creek is
a concrete-lined, trapezoidal channel that collects a small portion of urban runoff that is
discharged north of the intersection of Sunset Crossing Road and North Diamond Bar
Blvd. Runoff collected from catch basins drains west toward San Jose Creek in the City
of Industry. At the eastern terminus of Back Lot Lane, in the City of Walnut, lies very
small patch of riparian vegetation consisting of native and exotic trees and shrubs.
Flooding
Flood insurance maps issued by the Federal Emergency Management Agency (FEMA)2,
showing areas that may be subject to flooding in 100-year storm events, indicate that
Diamond Bar is at low risk for major flood events. Only a limited section of the City,
located north of SR-60 (Reed Canyon Channel at Brea Canyon Road and Lycoming
Street) are a slightly elevated flood potential. Surrounding areas at potentially elevated
risk of flooding include locations north of the 57 Freeway (across Baker Parkway) and
an area covering roughly 2,000 acres near the border with Pomona.
An extensive system of concrete-lined drainages, many of which are independent of the
natural streambeds, carries runoff through the City. Areas considered to be at elevated
risk of flooding may require maintenance of drainage channels, which can include
removal of native wetland and riparian vegetation, to maintain the flow of water
through the stormwater system. Diamond Bar’s generally low risk for flooding allows
for native riparian vegetation to be retained in natural streambeds, which can develop
into important habitat for various wildlife species.
BIOLOGICAL RESOURCES
Natural Communities
This section briefly describes the Natural Communities (also known as “plant
communities” or “vegetation types”) that occur in Diamond Bar and its Sphere of
Influence (i.e., Tonner Canyon/Significant Ecological Area 15, located in
unincorporated Los Angeles County south of the city limits). The following discussions
of Natural Communities refer to Natural Open Space Areas in the City and its Sphere of
Influence, which are mapped subsequently (see Figures 3a–3d, starting on page 12).
Please refer also to Appendix A, which describes the State-recommended methods used
to classify Natural Communities for this report.
2 Los Angeles county Flood Zone Definitions, See http://dpw.lacounty.gov/wmd/floodzone/docs/FZDLegend.pdf
10
ANNUAL AND PERENNIAL GRASSLANDS, VERNAL POOLS/SEASONAL POOLS
Natural Open Space Areas: 1, 2, 6, 8, 10, 13, Sphere of Influence
The bottom of Tonner Canyon supports extensive grasslands. Most alliances of the
widespread “California annual grassland” are not identified as Sensitive by CDFW, as
they generally represent areas disturbed over long periods (e.g., by grazing) that no
longer support many native plant species. Among the most prevalent alliances in the
Diamond Bar area is “annual brome grassland.” Dominant species include ripgut
brome (Bromus diandrus), foxtail brome (Bromus madritensis ssp. rubens), wild oats (Avena
fatua), foxtail barley (Hordeum murinum ssp. leporinum), shortpod mustard (Hirschfeldia
incana), black mustard (Brassica nigra), wild radish (Raphanus sativus), Italian thistle
(Carduus pycnocephalus), and tocalote (Centaurea melitensis). Some disturbance-adapted
native forbs, such as common fiddleneck (Amsinckia intermedia) and arroyo lupine
(Lupinus succulentus), may also occur.
Areas of perennial grassland, distinguished by possessing non-trace cover of native
grasses, are identified as Sensitive by CDFW. As examples, the Nassella spp. – Melica
spp. herbaceous alliance is characterized by having at least 2–5 percent cover of native
needlegrass (Nassella spp.) or other native grasses3; and the Bromus carinatus – Elymus
glaucus herbaceous alliance has California brome (Bromus carinatus) characteristically
present, with native plants providing more than 10 percent relative cover.4 It is likely
that vernal pools/seasonal ponds occur in the site’s grasslands, and/or along dirt roads
that pass through other Natural Communities.
Special-status species known to occur in Diamond Bar’s grasslands, or that have
potential to occur there, include Catalina mariposa lily (Calochortus catalinae) small-
flowered microseris (Microseris douglasii ssp. platycarpha), Golden Eagle (Aquila
chrysaetos), and Grasshopper Sparrow (Ammodramus savannarum).
COASTAL SAGE SCRUB, CACTUS SCRUB
Natural Open Space Areas: 1, 4, 7, 8, 10, Sphere of Influence
Hillsides throughout the Puente Hills support stands of coastal sage scrub and cactus
scrub, and this includes the dry, exposed slopes of Diamond Bar. Dominant native
shrubs species in coastal sage scrub include California sagebrush (Artemisia californica),
California buckwheat (Eriogonum fasciculatum), black sage (Salvia mellifera), coyote brush
(Baccharis pilularis), laurel sumac (Malosma laurina), lemonade berry (Rhus integrifolia),
and blue elderberry (Sambucus nigra ssp. caerulea). Within the Study Area, cactus scrub
is dominated by a combination of coastal prickly-pear (Opuntia littoralis) and shrubs
characteristic of coastal sage scrub. The CDFW recognizes most of these scrub/cactus
3 http://vegetation.cnps.org/alliance/536
4 http://vegetation.cnps.org/alliance/499
11
alliances as Sensitive Natural Communities5 in their own right, and they often support
special-status plant and/or wildlife species, such as intermediate mariposa lily
(Calochortus weedii ssp. intermedius), Hubby’s phacelia (Phacelia hubbyi), Coastal
California Gnatcatcher (Polioptila californica californica), and Cactus Wren
(Campylorhynchus brunneicapillus).
CHAPARRAL
Natural Open Space Areas: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, Sphere of Influence
On Diamond Bar’s north- and east-facing slopes, coastal sage scrub is replaced by taller
and denser shrubs and trees with greater requirements for moisture and shade. The
mosaic consists of three main Natural Communities: chaparral, oak woodland, and
walnut woodland. The lowland form of chaparral found in the study area is dominated
by such species as laurel sumac (Malosma laurina), toyon (Heteromeles arbutifolia),
sugarbush (Rhus ovata), chaparral honeysuckle (Lonicera subspicata), and blue elderberry
(Sambucus nigra ssp. caerulea). Special-status species associated potentially found in
chaparral in Diamond Bar include Fish’s milkwort (Polygala cornuta var. fishiae) and the
San Bernardino Ringneck Snake (Diadophis punctatus modestus).
COAST LIVE OAK WOODLAND, SAVANNAH
Natural Open Space Areas: 1, 3, 4, 6, 7, 8, 10, 11, 12, Sphere of Influence
Coast Live Oak Woodland, several associations of which are recognized as Sensitive by
CDFW, is characterized by stands of coast live oak (Quercus agrifolia), and in some areas
Engelmann oak (Quercus engelmannii), often growing together with chaparral and
walnut woodland, on Diamond Bar’s north- and east-facing slopes, as well as in the
bottoms of some drainage courses. Oak savannah, characterized by scattered oaks
growing in grassland, occurs in limited pockets and may be associated with human
disturbance of oak woodlands. Coast live oaks are valuable to a variety of native
wildlife, and are frequently utilized by nesting owls and hawks. Special-status species
that may be found in oak woodlands in the Study Area include the Southern California
Shoulderband Snail (Helminthoglypta tudiculata), Trask’s Shoulderband Snail
(Helminthoglypta traskii), and Long-eared Owl (Asio otus).
CALIFORNIA WALNUT WOODLAND, SAVANNAH
Natural Open Space Areas: 1, 2, 4, 5, 6, 10, 12, Sphere of Influence
This Natural Community, recognized as Sensitive by CDFW, is characterized by stands
of southern California black walnut (Juglans californica) growing in association with
chaparral and coast live oak woodland on Diamond Bar’s north- and east-facing slopes.
Walnut savannah, characterized by scattered walnuts growing in grassland, occurs in
limited pockets and may be associated with human disturbance of walnut woodlands.
5 https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=153609
12
Special-status species that may be found in walnut woodlands and walnut savannah in
Diamond Bar include the species indicated previously for oak woodlands and
chaparral.
RIPARIAN SCRUB AND WOODLANDS
Natural Open Space Areas: 1, 4, 5, 6, 7, 8, 10, 12, 13, Diamond Bar Golf Course, Sphere
of Influence
Various forms of riparian scrub and woodland, nearly all of them recognized as
Sensitive by CDFW, grow along streambeds in Diamond Bar. The dominant vegetation
consists of willows, such as arroyo willow (Salix lasiolepis) and red willow (S. laevigata),
mulefat (Baccharis salicifolia), California sycamore (Platanus racemosa), coast live oak
(Quercus agrifolia), southern California black walnut (Juglans californica), and blue
elderberry (Sambucus nigra ssp. caerulea). Special-status species that may be found in
riparian woodlands in Diamond Bar include the rough hedge-nettle (Stachys rigida var.
rigida), Western Pond Turtle (Emys marmorata), Yellow-breasted Chat (Icteria virens), and
Yellow Warbler (Setophaga petechia).
HUMAN-ALTERED HABITATS
Developed areas, such as turfed/landscaped parks and the Diamond Bar Golf Course,
generally do not support Natural Communities, but these areas may nevertheless play
important ecological roles. For example, the golf course includes large number of
ornamental trees that comprise a non-native woodland that supports a wide variety of
resident and migratory native birds, presumably including nesting raptors, and the
man-made lake provides habitat for migratory and resident ducks and other waterfowl.
Natural Open Space Areas
Figures 3a–3d, starting on the next page, depict 13 areas of extensive (>25 acres)
native/naturalized habitat in Diamond Bar. Also depicted are Diamond Bar Golf
Course and Tonner Canyon/Significant Ecological Area 15, within the city’s Sphere of
Influence. The figures also show potential habitat connections/choke points for wildlife
movement between blocks of natural open space. Figures 3a–3d provide a basis for
generally characterizing the existing ecological conditions within Diamond Bar and its
Sphere of Influence, without accounting for such distinctions as the boundaries of
parklands or private lots.
13
14
15
16
Resource Protection
Recommendations
17
Resource Protection Recommendations
Table A, below, describes and characterizes the ecological characteristics of each
mapped natural open space area at a general level of detail appropriate for a General
Plan. Recommendations are made for the establishment of biological protection
overlays for sensitive habitat areas with high ecological values (e.g., native woodlands
and coastal sage scrub). Note that sensitive natural resources (e.g., special-status
species) and/or important ecological functions (e.g., movement of wildlife) could also
occur outside of the identified areas. More detailed, project-specific surveys would be
required to accurately and adequately describe the ecological resources found in any
open space area.
Table A. Resource Protection Recommendations
Area Acres Description/Main Communities/ Resource Protection Recommendations
1 926
Largest block of natural open space in Diamond Bar, including Pantera Park and northern
part of Tres Hermanos Ranch.
Grassland, Coastal Sage Scrub, Cactus Scrub, Chaparral, Oak Woodland, Walnut Woodland,
Riparian, Human-altered Habitats.
Establish biological protection overlay to conserve (a) large blocks of contiguous natural
habitat for Golden Eagles, Mountain Lions, and other species with large foraging areas, (b)
native scrub habitats with documented populations of California Gnatcatcher and Cactus
Wren, (c) wetland and riparian habitats, and (d) native woodlands; maintain and fortify
habitat connections and wildlife movement opportunities; minimize loss, fragmentation, and
degradation of Natural Communities.
2 64
Only large block of natural open space in Diamond Bar north of 60 Freeway.
Grassland, Coastal Sage Scrub, Chaparral, Coast Live Oak Woodland, Human-altered
Habitats.
Establish biological protection overlay to conserve native scrub habitats and native
woodlands; minimize loss, fragmentation, and degradation of Natural Communities; maintain
and fortify habitat connections and wildlife movement opportunities.
3 72
“Island” of natural open space between Charmingdale Road and Armitos Place.
Coast Live Oak Woodland, Coastal Sage Scrub, Grassland, Human-altered Habitats.
Establish biological protection overlay to conserve native scrub habitats and native
woodlands; minimize loss, fragmentation, and degradation of Natural Communities.
4 438
Includes Summitridge Park and Steep Canyon/Diamond Bar Creek.
Coastal Sage Scrub, Cactus Scrub, Oak Woodland, Riparian, Grassland, Human-altered
Habitats.
Establish biological protection overlay to conserve native scrub habitats with documented
populations of California Gnatcatcher and Cactus Wren, wetland and riparian habitats, and
native woodlands; minimize loss, fragmentation, and degradation of Natural Communities;
maintain and fortify habitat connections and wildlife movement opportunities.
18
Area Acres Description/Main Communities/ Resource Protection Recommendations
5 62
Includes Sycamore Canyon Park/Diamond Bar Creek.
Coastal Sage Scrub, Cactus Scrub, Oak Woodland, Riparian, Grassland, Human-altered
Habitats.
Establish biological protection overlay to conserve native scrub habitats, wetland and riparian
habitats, and native woodlands; minimize loss, fragmentation, and degradation of Natural
Communities; maintain and fortify habitat connections and wildlife movement opportunities.
6 196
Slopes east of City Hall.
Oak Woodland, Walnut Woodland, Oak/Walnut Savannah, Chaparral, Grassland, Coastal
Sage Scrub, Human-altered Habitats, Riparian.
Establish biological protection overlay to conserve native woodlands and savannah;
minimize loss, fragmentation, and degradation of Natural Communities; maintain and fortify
habitat connections and wildlife movement opportunities.
7 154
Includes Larkstone Park.
Coast Live Oak Woodland, Oak Savannah, Coastal Sage Scrub, Chaparral, Riparian,
Grassland, Human-altered Habitats.
Establish biological protection overlay to conserve native woodlands, wetland and riparian
habitats, and native scrub habitats; minimize loss, fragmentation, and degradation of Natural
Communities; maintain and fortify habitat connections and wildlife movement opportunities.
8 231
West of 57 Freeway, south of Pathfinder Road.
Oak Woodland, Oak/Walnut Savannah, Coastal Sage Scrub, Chaparral, Grassland, Human-
altered Habitats.
Establish biological protection overlay to conserve native woodlands and savannah, and
native scrub habitats; minimize loss, fragmentation, and degradation of Natural Communities;
maintain and fortify habitat connections and wildlife movement opportunities.
9 27
Southwestern corner.
Oak Woodland, Chaparral, Grassland.
Establish biological protection overlay to conserve native woodlands; minimize loss,
fragmentation, and degradation of Natural Communities.
10 712
Tonner Canyon tributaries.
Chaparral, Oak Woodland, Walnut Woodland, Oak/Walnut Savannah, Coastal Sage Scrub,
Riparian, Grassland, Human-altered Habitats.
Establish biological protection overlay to conserve native scrub habitats, wetland and riparian
habitats, and native woodlands and savannah; minimize loss, fragmentation, and degradation
of Natural Communities; maintain and fortify habitat connections and wildlife movement
opportunities.
11 39
Southwestern section of The Country; part of Significant Ecological Area 15.
Oak Woodland, Chaparral, Grassland.
Establish biological protection overlay to conserve native woodlands; minimize loss,
fragmentation, and degradation of Natural Communities.
19
Area Acres Description/Main Communities/ Resource Protection Recommendations
12 197
Slopes west of Ridge Line Road.
Oak Woodland, Walnut Woodland, Chaparral, Grassland, Coastal Sage Scrub, Human-
altered Habitats, Riparian.
Establish biological protection overlay to conserve native woodlands, wetland and riparian
habitats, and native scrub habitats; minimize loss, fragmentation, and degradation of Natural
Communities; maintain and fortify habitat connections and wildlife movement opportunities.
13 100
Northeastern part of The Country, adjacent to Tres Hermanos Ranch.
Grassland, Coastal Sage Scrub, Chaparral, Oak Woodland, Riparian, Human-altered
Habitats.
Establish biological protection overlay to conserve (a) large blocks of contiguous natural
habitat for Golden Eagles, Mountain Lions, and other species with large foraging areas, (b)
wetland and riparian habitats, and (c) native woodlands; maintain and fortify habitat
connections and wildlife movement opportunities; minimize loss, fragmentation, and
degradation of Natural Communities.
Diamond
Bar GC 174
Golf course that provides wildlife habitat.
Riparian, Human-altered Habitats (including man-made pond).
Conserve wetland and riparian habitats; maintain and fortify habitat connections and wildlife
movement opportunities.
Sphere of
Influence 3,513
Large and important area of natural open space south of Diamond Bar, including Pantera
Park and northern part of Tres Hermanos Ranch; heart of Significant Ecological Area 15.
Chaparral, Oak Woodland, Walnut Woodland, Oak/Walnut Savannah, Riparian, Grassland,
Coastal Sage Scrub.
Establish biological protection overlay to conserve (a) large blocks of contiguous natural
habitat for Golden Eagles, Mountain Lions, and other species with large foraging areas, (b)
wetland and riparian habitats, (c) native woodlands, and (d) native scrub habitats; minimize
loss, fragmentation, and degradation of Natural Communities.
Sensitive Resources
This biological resources report acknowledges federal, state, and local laws and
ordinances designed to protect and conserve sensitive resources, and identifies City
policies designed to help achieve this objective. For purposes of this report, a sensitive
resource refers to any of the following:
• A Natural Community recognized as having special-status by federal, State, and/or
local governments, and requiring a permit or agreement prior to its disturbance.
• A plant or animal species identified by federal or state governments as endangered,
threatened, rare, protected, sensitive, or a Species of Special Concern.
• A plant or animal that listed by a state or federal agency as a candidate species or
proposed for state or federal listing.
20
SENSITIVE NATURAL COMMUNITIES
The State of California identifies as “Sensitive” the following Natural Communities that
occur in Diamond Bar and its Sphere of Influence:
• Native Grasslands.
• Coastal Sage Scrub.
• Coast Live Oak Woodland (Q. agrifolia/Juglans californica; Q. agrifolia/Q.
berberidifolia/x acutidens; Q. agrifolia/Salvia leucophylla – Artemisia californica; Q.
agrifolia/Salix lasiolepis)6.
• California Walnut Woodland.
• Riparian Scrub and Woodland.
SPECIAL-STATUS SPECIES
In the following Table B, special-status plants and wildlife judged to have potential to
occur within Diamond Bar and its Sphere of Influence are identified and briefly
discussed. The potential for occurrence (low, moderate, high, or known to be present) is
based upon consideration of the species’ habitat requirements and the distribution of
previous verified or highly credible records.
Table B uses the following abbreviations:
• E Endangered (listed by State or Federal governments). “Take” of the
species or disturbance of occupied habitat are prohibited unless
specifically authorized.
• FP Fully Protected by the State of California. These species may not be taken or
possessed at any time, although take may be authorized for necessary
scientific research.
• T Threatened (listed by State or Federal governments). “Take” of the
species or disturbance of occupied habitat are prohibited unless
specifically authorized.
• SSC Species of Special Concern. The California Department of Fish and Wildlife
has designated certain vertebrate species as Species of Special Concern
because declining population levels, limited ranges, and/or continuing
threats have made them vulnerable to extinction. The goal of designating
species as Species of Special Concern is to halt or reverse their decline by
6 In addition to the four coast live oak associations designated as “Sensitive” by CDFW, oak woodlands
within the unincorporated Sphere of Influence are subject to the Los Angeles County Oak Woodlands
Conservation Management Plan pursuant to California Public Resources Code Section 21083 (requires a
county, when acting as a CEQA Lead Agency, to determine whether a proposed project “may result in a
conversion of oak woodlands that will have a significant effect on the environment”).
21
calling attention to their plight and addressing the issues of concern early
enough to secure their long term viability. Not all Species of Special
Concern have declined equally; some species may be just starting to
decline, while others may have already reached the point where they meet
the criteria for listing as a Threatened or Endangered species under the State
and/or Federal Endangered Species Acts.
• CNPS California Native Plant Society. Table B includes plant species
assigned the following ranks by CNPS:
o 1B.1, referring to species CNPS considers to be rare, threatened, or endangered in
California and elsewhere; seriously threatened in California (over 80% of occurrences
threatened / high degree and immediacy of threat).
o 1B.2, referring to species CNPS considers to be rare, threatened, or endangered in
California and elsewhere; moderately threatened in California (20-80% of
occurrences threatened / moderate degree and immediacy of threat).
o 1B.3, referring to species CNPS considers to be rare, threatened, or endangered in
California and elsewhere; not very threatened in California (less than 20% of
occurrences threatened / moderate degree and immediacy of threat).
o 2B.2, referring to species CNPS considers to be rare, threatened, or endangered in
California, but more common elsewhere; moderately threatened in California (20-
80% occurrences threatened / moderate degree and immediacy of threat).
o 4.1, referring to species of limited distribution or infrequent throughout a broader
area in California, whose status should be monitored regularly; moderately
threatened in California (>80% occurrences threatened / moderate degree and
immediacy of threat).
o 4.2, referring to species of limited distribution or infrequent throughout a broader
area in California, whose status should be monitored regularly; moderately
threatened in California (20-80% occurrences threatened / moderate degree and
immediacy of threat).
o 4.3, referring to species of limited distribution or infrequent throughout a broader
area in California, whose status should be monitored regularly; not very threatened in
California (less than 20% of occurrences threatened / low degree and immediacy of
threat or no current threats known).
• NatureServe Element Rankings. In some cases, species have not been granted
special status by state or federal agencies, but they may be recognized as
ecologically sensitive by the California Natural Diversity Database (CNDDB),
which uses a ranking methodology maintained by NatureServe. Species are given a
Global rank (G-rank) that applies to the taxon’s entire distribution, and a State rank
(S-rank) that applies to the taxon’s state distribution. Taxa with rankings of G1, G2,
G3, S1, S2, or S3 may be considered “sensitive” and potentially worthy of special
consideration in resource planning. NatureServe Element Rankings are identified in
Table B only for taxa that have no other federal or state special status.
22
NatureServe Ranks:
o G1, Critically Imperiled, referring to taxa at very high risk of extinction due to extreme
rarity ( often 5 or fewer populations), very steep declines, or other factors.
o G2, Imperiled, referring to taxa at high risk of extinction due to very restricted range, very
few populations (often 20 or fewer), steep declines, or other factors.
o G3, Vulnerable, referring to taxa at moderate risk of extinction due to a restricted range,
relatively few populations (often 80 or fewer), recent and widespread declines, or other
factors.
o S1, Critically Imperiled, referring to taxa critically imperiled in the state because of extreme
rarity (often 5 or fewer populations) or because of factor(s) such as very steep declines
making it especially vulnerable to extirpation from the state.
o S2, Imperiled, referring to taxa imperiled in the state because of rarity due to very restricted
range, very few populations (often 20 or fewer), steep declines, or other factors making it
very vulnerable to extirpation from the state.
o S3, Vulnerable, referring to taxa vulnerable in the state due to a restricted range, relatively
few populations (often 80 or fewer), recent and widespread declines, or other factors
making it vulnerable to extirpation from the state.
Table B. Special-Status Species
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Plants
Astragalus
brauntonii
Braunton’s
Milk-Vetch E — 1B.1
Associated with
calcareous soils.
Unrecorded in the
Puente Hills, but
populations to the
northwest (San
Gabriel Mts.) and
southeast (Chino
Hills, Santa Ana
Mts.).
Moderate potential to
occur in calcareous
substrate, if present.
Detectable only after fire
or other disturbance.
Brodiaea filifolia
Thread-
leaved
Brodiaea
— — 1B.1
Associated with clay
soils. Unrecorded in
the Puente Hills, but
populations to the
north (San Gabriel
Mts.) and southeast
(Santiago Hills).
Low potential to occur in
vernal pools, grasslands, or
openings in coastal sage
scrub.
Calochortus
catalinae
Catalina
Mariposa
Lily
— — 4.2
Widespread in
region, occurring in
clay soils.
Occurs in grasslands or
openings in coastal scrub
or chaparral.
Calochortus
clavatus
var. gracilis
Slender
Mariposa
Lily
— — 1B.2
Unrecorded in the
Puente Hills; popu-
lations to the north-
west (San Gabriel
Mts.).
Low potential to occur in
openings in coastal scrub
or chaparral.
23
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Calochortus
plummerae
Plummer’s
Mariposa
Lily
— — 4.2
Several recent
records of C. weedii
intermedius from
hills south of
Diamond Bar, within
the City’s Sphere of
Influence, may be C.
plummerae hybrids.
Potentially present. Occurs
in openings in coastal sage
scrub or chaparral.
Calochortus weedii
var. intermedius
Intermediate
Mariposa
Lily
— — 1B.2
Several recent
records from hills
south of Diamond
Bar, within the City’s
Sphere of Influence,
identified as C.
weedii intermedius,
but with potential for
hybridization with C.
plummerae.
Occurs in openings in
coastal sage scrub and
chaparral.
Convolvulus
simulans
Small-
flowered
Morning-
glory
— — 4.2
Scattered records
from the region,
including an old
record from 1 mile
east of Brea.
Moderate potential to
occur in grasslands or
openings in coastal sage
scrub. Found in moist
areas.
Dudleya
multicaulis
Many-
stemmed
Dudleya
— — 1B.2
Recorded close to
Diamond Bar, in
west Pomona.
Moderate potential to
occur in openings in
coastal sage scrub or
chaparral.
Horkelia cuneata
ssp. puberula
Mesa
Horkelia — — 1B.1
Unrecorded in the
Puente Hills;
scattered records
across the region.
Low to moderate potential
to occur in sandy openings
in chaparral and oak
woodland.
Juglans
californica
Southern
California
Black
Walnut
— — 4.2
Widespread in
region, including
Diamond Bar and its
Sphere of Influence.
Walnut and oak/walnut
woodlands occur
throughout Diamond Bar
and surrounding hills.
Lepidium
virginicum var.
robinsonii
Robinson’s
Peppergrass — — 4.3
Numerous historical
records from the
county’s interior
foothills, including
the western Puente
Hills; a few recent
records in and near
Diamond Bar.
Occurs in openings in
coastal sage scrub and
chaparral.
Microseris
douglasii ssp.
platycarpha
Small-
flowered
Microseris
— — 4.2
Recorded in
Diamond Bar, south
of Diamond Ranch
High School.
Occurs in grasslands.
Phacelia hubbyi Hubby’s
Phacelia — — 4.2
Several recent
records from
Pomona, Whittier,
and the Santa Ana
Mountain foothills.
High potential to occur in
openings in chaparral or
coastal scrub, such as
along edges of roads and
trails.
24
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Piperia cooperi Cooper’s
Rein-Orchid — — 4.2
Unrecorded in the
Puente Hills;
historical records
from as close as
Claremont and the
Santa Ana River
Canyon.
Low potential to occur in
oak/walnut woodlands,
chaparral, or coastal sage
scrub.
Polygala cornuta
var. fishiae
Fish’s
Milkwort — — 4.3
Recorded in Chino
Hills State Park and
San Gabriel Mts.
Moderate to high potential
to occur in oak/walnut
woodlands or chaparral.
Pseudognaphalium
leucocephalum
White
Rabbit-
tobacco
— — 2B.2
Unrecorded in the
Puente Hills; few
recent records from
surrounding areas.
Low potential to occur in
any sandy wash habitat
that may exist in the study
area.
Quercus
engelmannii
Engelmann
Oak — — 4.2
Recorded in the
Chino/Puente Hills,
La Habra and Yorba
Linda USGS quads.
Moderate potential to
occur in oak/walnut
woodlands.
Senecio aphanactis California
Groundsel — — 2B.2
Historical records
from San Dimas; few
recent records from
surrounding areas.
Moderate potential to
occur in chaparral,
oak/walnut woodlands, or
coastal sage scrub.
Symphyotrichum
defoliatum
San
Bernardino
Aster
— — 1B.2
Historical records
from southeastern
Los Angeles County.
Presumed extirpated.
Very low potential to occur
in moist areas, meadows.
Invertebrates
Bombas crotchii Crotch’s
Bumblebee — S1S2 —
Historical and recent
records scattered
around southern
California.
High potential to occur in
various habitats.
Helminthoglypta
tudiculata
Southern
California
Shoulder-
band Snail
— S1S2 —
Numerous records
from coastal slope of
southern California.
High potential to occur in
various habitats.
Helminthoglypta
traskii traskii
Trasks’s
Shoulder-
band Snail
— G1G2
S1 —
Numerous records
from coastal slope of
southern California.
High potential to occur in
various habitats.
Amphibians
Taricha torosa Coast Range
Newt — SSC —
Not known from
Chino Hills. Nearest
records in San
Gabriel Mts.
Low potential to occur in
and around permanent
water.
Spea hammondii Western
Spadefoot — SSC —
Widespread in region
but limited to
expansive natural
open space areas.
Moderate to high potential
to occur in extensive
grasslands and adjacent
communities with
temporary rain-pools for
breeding.
25
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Reptiles
Emys marmorata Western
Pond Turtle — SSC —
Found in expansive
natural areas, in and
around permanent
water that lacks non-
native turtles or
exotic predators.
Large population known
from Brea Creek; probably
occurs elsewhere in the
study area. Occurs in
creeks and ponds; lays
eggs in nearby uplands.
Phrynosoma
blainvillii
Coast
Horned
Lizard
— SSC —
Found in expansive
natural areas with
sandy openings and
native harvester ants.
High potential to occur in
areas of extensive
chaparral, coastal sage
scrub, and grassland.
Aspidoscelis tigris
stejnegeri
Coastal
Whiptail — SSC —
Widespread in the
region, in various
habitats.
Occurs in chaparral and
coastal sage scrub.
Anniella stebbinsi
So.
California
Legless
Lizard
— SSC —
Local in a variety of
habitats with sandy
soil or deep leaf-
litter.
Moderate potential in
chaparral and
chaparral/oak habitats.
Lampropeltis
zonata pulchra
San Diego
Mountain
Kingsnake
— SSC —
Widespread in the
region, in various
habitats.
Moderate potential to
occur in chaparral, coastal
sage scrub, oak
woodlands, and along
streams.
Arizona elegans
occidentalis
California
Glossy Snake — SSC —
Widespread, but
uncommon, in
habitats with soil
loose enough for
easy burrowing.
Moderate potential to
occur in areas that have
extensive patches of loose
soil.
Salvadora
hexalepis
virgultea
Coast Patch-
nosed Snake — SSC —
Widespread in the
region, in brushy and
rocky habitats.
Moderate potential to
occur in chaparral, coastal
sage scrub, oak
woodlands, and along
streams.
Thamnophis
hammondii
Two-striped
Garter Snake — SSC —
Widespread in the
region, in and
around perennial
water.
Moderate potential to
occur near perennial
water.
Crotalus ruber
Red
Diamond
Rattlesnake
— SSC — Widespread in the
region.
Occurs in cactus scrub,
coastal sage scrub, and
chaparral.
Birds
Geococcyx
californianus
Greater
Roadrunner — — —
Widespread in
expansive natural
areas with shrub
cover. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Resident in coastal sage
scrub and chaparral
habitats.
26
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Aquila
chrysaetos Golden Eagle — FP —
Formerly widespread
in many habitats, but
now limited to
expansive natural
areas. Nests on cliffs
and in tall trees away
from settlements.
Regularly observed
foraging in northeastern
part of study area. Pair
appears to be resident in
the Chino Hills/Diamond
Bar area; nesting status
unknown. Additional birds
may occur during
migration/winter.
Circus hudsonius Northern
Harrier — SSC —
Nests on the ground
in expansive open
space areas; more
widespread during
migration and winter.
Winters in open grassland
habitats. Moderate
potential to nest in the
northeastern and southern
parts of study area.
Elanus leucurus White-tailed
Kite — FP —
Nests in trees within
expansive open
space areas; more
widespread during
migration and winter.
Forages in
rangelands and
marshy areas.
One or more observed
near Diamond Ranch High
School on unspecified date
(Sage Environmental
Group 2012). High
potential to occur in
migration and winter,
especially in northeastern
and southern parts of study
area. Moderate potential to
nest in the northeastern or
southeastern parts of the
study area.
Buteo regalis Ferruginous
Hawk — — —
Winters in expansive
rangelands and
agricultural areas in
the region. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Moderate to high potential
to occur in migration and
winter, in northeastern and
southern parts of study
area. Does not nest in the
region.
Athene cunicularia Burrowing
Owl — SSC —
Nesting population
west of the deserts
nearly extirpated.
Winters rarely and
locally, usually in
expansive open
space areas.
Likely extirpated as nesting
species in Diamond Bar
area. Moderate potential to
occur in migration and
winter, especially in
northeastern and southern
parts of study area.
Asio otus Long-eared
Owl — SSC —
Resident in oak
woodlands, typically
>1 km from urban
areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Low to moderate potential
to occur in woodlands in
southeastern part of study
area.
Asio flammeus Short-eared
Owl — SSC —
Winters in expansive
open areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Low potential to occur in
migration and winter, in
northeastern and southern
parts of study area. Does
not nest in the region.
27
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Falco mexicanus Prairie
Falcon — — —
Winters in expansive
rangelands and
agricultural areas in
the region. Nests on
remote cliffs.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
Low to moderate potential
to occur in migration and
winter, in northeastern and
southern parts of study
area. Unlikely to nest due
to lack of remote cliffs.
Empidonax traillii Willow
Flycatcher E E —
Does not nest in the
local area.
Uncommon during
migration.
No potential for nesting.
Species occurs in the study
area regularly during
migration periods.
Lanius
ludovicianus
Loggerhead
Shrike — SSC —
Nests rarely in the
region, in expansive
open space areas;
more widespread in
migration and winter.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
High potential to occur in
migration and winter,
especially in northeastern
and southern parts of study
area. Low to moderate
potential to nest in the
study area.
Vireo bellii bellii Least Bell’s
Vireo E E —
Nests uncommonly
in riparian scrub and
woodlands, often in
mulefat (Baccharis
salicifolia) or willow
(Salix spp.).
Moderate potential to nest
in riparian habitats,
especially in Tonner
Canyon.
Eremophila
alpestris Horned Lark — — —
Nests and winters in
expansive rangelands
and agricultural areas
in the region.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
Low potential to occur in
the northeastern and
southern parts of study
area.
Campylorhynchus
brunneicapillus
Cactus
Wren,
coastal
populations
— SSC —
Rare and declining
resident of cactus
scrub habitat.
Resident in well-developed
cactus scrub, including
Summitridge Park, Pantera
Park, Steep Canyon, and
hills south of Diamond
Ranch High School.
Polioptila
californica
californica
Coastal
California
Gnatcatcher
T SSC —
Uncommon resident
in coastal sage scrub
habitat, favoring
shallow slopes and
elevations below
1,500 feet.
Resident in coastal sage
scrub and cactus scrub,
including Summitridge
Park, Pantera Park, Steep
Canyon, and hills south of
Diamond Ranch High
School.
Sialia currucoides Mountain
Bluebird — — —
Winters in expansive
open areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
High potential to occur, at
least during some winters,
in northeastern and
southern parts of study
area. Does not nest in the
region.
Icteria virens
Yellow-
breasted
Chat
— SSC —
Nests uncommonly
in riparian scrub and
woodlands.
High potential to nest in
riparian habitats, especially
in Tonner Canyon.
28
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Setophaga
petechia
Yellow
Warbler — SSC — Nests in riparian
woodlands.
High potential to nest in
riparian habitats, especially
in Tonner Canyon.
Pooecetes
gramineus
Vesper
Sparrow — — —
Winters in expansive
open areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
High potential to occur in
northeastern and southern
parts of study area. Does
not nest in the region.
Ammodramus
savannarum
Grasshopper
Sparrow — SSC —
Nests in expansive
grasslands and
rangelands.
High potential to nest in
open grassland and
rangeland habitat. Several
eBird records from the
Diamond Bar area in the
1990s; lack of recent
records probably reflects
lack of survey effort.
Sturnella neglecta Western
Meadowlark — — —
Nests rarely in the
region, in expansive
open space areas;
widespread in
migration and winter.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
Occurs in open areas
throughout the study area;
moderate potential to nest
in the northeastern or
southern parts of study
area.
Agelaius tricolor Tricolored
Blackbird — SSC —
Nests in wetlands
adjacent to
expansive grasslands
and rangelands
required for foraging.
Winters in
rangelands and
parks.
Low potential to nest in the
study area. Moderate
potential to forage in open
grassland and rangeland
habitat during the nesting
season. Recorded in winter
at parks in the study area.
Mammals
Antrozous
pallidus Pallid Bat None SSC —
Widespread in
chaparral and similar
habitats, foraging on
the ground and in
vegetation. Roosts in
rock crevices and
under tree bark.
Maternal roosts
active between
March and August.
High potential; chaparral
and scrub on the site are
potentially suitable for
foraging and oaks provide
potential roosting sites
under exfoliating bark and
in cavities.
Eumops perotis
californicus
Western
Mastiff Bat None SSC —
Roosts in cliff
crevices and in
buildings.
Low potential; the species
may fly over the site
occasionally while
foraging, but suitable cliff
roosting habitat probably
absent.
Lasiurus blossevillii Western
Red Bat None SSC —
Roosts in foliage of
many types of tree;
feeds over a wide
variety of habitats.
Moderate potential to roost
in oak woodlands or
landscape trees; high
potential to forage over
undeveloped areas.
29
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Lasiurus xanthinus Western
Yellow Bat None SSC —
Roosts primarily or
entirely in palms;
often forages over
water.
Moderate potential to roost
in palm trees and to forage
over water features.
Chaetodipus fallax
fallax
NW San
Diego Pocket
Mouse
None SSC —
Scrub habitats with
sandy or gravelly
soils.
High potential to occur in
cactus scrub and coastal
sage scrub habitats with
sutiable soils.
Neotoma lepida
intermedia
San Diego
Desert
Woodrat
None SSC —
Widespread in scrub
habitats, especially
those with cactus.
High potential to occur in
cactus-containing scrub.
Lepus californicus
bennettii
San Diego
Black-tailed
Jackrabbit
None SSC —
Occurs in various
open habitats,
usually in expansive
open space areas.
Low potential to occur in
the northeastern and
southern parts of the study
area.
Taxidea taxus American
Badger None SSC
Occurs in various
habitats, usually in
expansive open
space areas.
Moderate to high potential
to occur in the
northeastern and southern
parts of the study area.
EFFECTS OF DEVELOPMENT ON BIOLOGICAL RESOURCES
The capacity for a given natural open space area to maintain its ecological integrity (e.g.,
its resistance to invasion by exotic species, capacity to support special-status species)
depends upon such considerations as (a) size, with larger natural areas generally
possessing greater ecological value than do smaller ones; (b) plant communities
represented, with relatively undisturbed native communities generally being more
valuable than disturbed non-native communities; and (c) proximity to adjacent open
spaces, with areas linked to other natural areas generally possessing greater ecological
value compared with areas of similar size that are functionally isolated from other
natural areas.
A small, functionally isolated area that provides habitat for a rare plant or wildlife
species may have some ecological value, but conservation of such areas may prove to be
practically infeasible due to habitat degradation that often occurs near development
edges. Ecologically damaging “edge effects” include repeated clearing of habitat for fuel
modification leading to replacement of native plants with disturbance-adapted exotic
weeds; invasion of natural habitat by exotic ants facilitated by artificial irrigation near
homes; predation of birds, reptiles, and mammals by outdoor cats; and changes in
wildlife patterns associated with exterior lighting. To avoid perpetuating damaging
patterns of development that result in ever-smaller blocks of functionally isolated
habitat, the Open Space and Conservation Element must contain land-use policies that
encourage the preservation, restoration, and appropriate management of larger blocks
of well-connected habitat.
Readers seeking detailed information on these topics, with relevant citations from the
scientific literature, should refer to Appendix A.
30
Edge/Fragmentation Effects on Wildlife Movement
Constricting the movement of wildlife and plant seeds increases the risk of local
extinctions. Habitat fragmentation consequently threatens the viability of native plant
and wildlife populations in preserved areas. Large areas of habitat, or narrower
linkages of habitat between large areas, provide movement opportunities for wildlife.
Movement serves to facilitate the geographic distribution of genetic material, thus
maintaining a level of variability in the gene pool of an animal population. Influxes of
animals from nearby larger populations contribute to the genetic diversity of a local
population, helping to ensure the population’s ability to adapt to changing
environmental conditions. This is mainly accomplished through the dispersal of
juveniles from their natal territories, but may also involve movements in response to
drought or other adverse environmental conditions, or in response to wildfires or other
catastrophic events. Many plant species that depend on relatively sedentary insects for
pollination also benefit from habitat linkages that allow for genetic exchange and
dispersal. Likewise, plant seeds and propagules can be transported via the feces, fur, or
feathers of birds or mammals. Fragmentation effects are not limited to the physical
severing of movement routes, such as through the construction of a road or housing
development, but can include “edge effects” reviewed and described above. For
example, increases in night lighting and noise can disrupt the movement patterns of
species not well-adapted to such effects.
WILDLIFE MOVEMENT ISSUES IN THE PUENTE-CHINO HILLS
The Puente-Chino Hills ecosystem encompasses portions of four counties, and the open
space network in this area is sometimes referred to as the “Puente-Chino Hills Wildlife
Corridor.” Preserving land in the corridor has been a cooperative endeavor with other
public agencies and many nonprofit organizations. An important analysis by the
Conservation Biology Institute (2005), Maintaining Ecological Connectivity Across the
“Missing Middle” of the Puente-Chino Hills Wildlife Corridor, describes the situation as
follows (page v):
The Puente-Chino Hills Wildlife Corridor is a peninsula of mostly undeveloped hills jutting
about 42 km (26 miles) from the Santa Ana Mountains into the heart of the densely
urbanized Los Angeles Basin. Intense public interest in conserving open space here has
created a series of reserves and parks along most of the corridor’s length, but significant
gaps in protection remain. These natural habitat areas support a surprising diversity of
native wildlife, from mountain lions and mule deer to walnut groves, roadrunners, and
horned lizards. But maintaining this diversity of life requires maintaining functional
connections along the entire length of the corridor, so that wildlife can move between
reserves—from one end of the hills to the other.
Already the corridor is fragmented by development and crossed by numerous busy roads,
which create hazards and in some cases barriers to wildlife movement. Proposed
developments threaten to further degrade or even sever the movement corridor, especially
within its so-called “Missing Middle.” This mid-section of the corridor system, stretching
from Tonner Canyon on the east to Harbor Boulevard on the west, includes several large
properties proposed for new housing, roads, golf courses, and reservoirs. Such
31
developments would reduce habitat area and the capacity to support area-dependent
species and, if poorly designed, could block wildlife movement through the corridor.
The above-quoted report considered numerous studies of wildlife movement conducted
in the Puente-Chino Hills, and other relevant literature on wildlife movement corridors,
and recommended “conservation and management actions to prevent further loss of
ecological connectivity and retain native species.” The “Missing Middle” analysis
identified the following wildlife movement issues specifically relevant to Diamond Bar
and its Sphere of Influence:
• Tonner Canyon Bridge represents the only viable location for deer, mountain lions,
bobcats, and other species to pass under the 57 Freeway.
• Any development in middle and especially lower Tonner Canyon could have
severe impacts on corridor function, especially if wildlife access to Tonner Canyon
Bridge is reduced. Any development that blocks access through the bridge area
would make the 57 Freeway a complete barrier to many species and would likely
lead to wildlife extirpations in segments farther west.
• An earlier plan to build a road running the length of Tonner Canyon would have
split the Chino-Tonner “subcore” in two, potentially rendering dysfunctional the
critical Tonner Bridge wildlife undercrossing for wide-ranging species such as the
mountain lion, bobcat, and mule deer.
• At least the middle and lower portions of Tonner Canyon should be conserved,
including a prohibition on any new road or other development that would fragment
this critical habitat block.
• No project should be approved that would increase traffic under the Tonner Bridge
or add any new impediments (structures, lights, noise, etc.) to the vicinity of the
bridge.
• Restore riparian vegetation along Tonner Creek, where degraded by oil
development activities.
• Fencing may be warranted along the 57 Freeway if monitoring suggests road
mortality is high.
Planning of any future development in Diamond Bar and its Sphere of Influence should
take exceptional care to preserve and enhance the viability of the Puente-Chino Hills
Wildlife Corridor.
Regional Planning in the Puente-Chino Hills Wildlife Corridor
Two agencies are specifically involved in planning development and taking
conservation actions in and around the Puente-Chino Hills Wildlife Corridor.
The Wildlife Corridor Conservation Authority (WCCA) was established to provide for
the proper planning, conservation, environmental protection, and maintenance of lands
32
within and around the Puente-Chino Hills Wildlife Corridor. Its goal is to assure that
sufficient continuity of habitat can be preserved to maintain a functioning wildlife
corridor made up of about 40,000 acres of land located between the Santa Ana
Mountains and Whittier Hills. The governing board of the WCCA consists of
representatives from the cities of Brea, Whittier, Diamond Bar, La Habra Heights, the
Santa Monica Mountains Conservancy, California Department of Parks and Recreation,
California Department of Fish and Game (ex officio member), Los Angeles County, and
two public members. A large Advisory Committee meets separately to provide input.
The WCCA consistently provides comments on development proposals and other
projects to support environmentally sensitive activities in the Puente-Chino Hills
Wildlife Corridor.
The Puente Hills Habitat Preservation Authority (PHHPA) is a public agency, Joint
Powers Authority, with a Board of Directors consisting of the City of Whittier, County
of Los Angeles, Sanitation Districts of Los Angeles County, and the Hacienda Heights
Improvement Association. The jurisdiction of the PHHPA extends from the intersection
of the 605 and 60 Freeways east to Harbor Boulevard. The PHHPA is dedicated to the
acquisition, restoration, and management of open space in the Puente Hills for
preservation of the land in perpetuity, with the primary purpose to protect the
biological diversity.
NATURAL RESOURCE CONSERVATION POLICIES
The City of Diamond Bar has developed a suite of conservation measures, presented in
this section, designed to allow for the planned growth of the City while protecting and
conserving irreplaceable natural communities and their component species. These
policies align the local approach to development with the conservation regulations and
policies set forth by the federal government (e.g., the federal Endangered Species Act);
the State of California (e.g., the California Environmental Quality Act and the California
Fish and Game Code); and local entities (e.g., the Los Angeles County Oak Woodlands
Conservation Plan; see Los Angeles County Oak Woodlands Habitat Conservation
Strategic Alliance 2011, Los Angeles County Dept. of Regional Planning 2014).
Prioritizing the identification and protection of sensitive natural resources facilitates
efforts of City planners and elected officials to ensure that Diamond Bar remains a
beautiful and desirable place to live.
Goals and Policies of the Open Space and Conservation Element
• RC-I-1. Obtain and designate Open Space land through acquisition techniques,
such as:
a. Design new development projects emphasizing preservation of sensitive natural
resources, natural geological features, and wildlife corridors and habitat
linkages, through site design approaches that include greenbelts, landscaping
with locally native, drought-adapted plants, and dedication of a portion of the
site as natural open space.
33
b. Allow for acquisition of open space lands during the entitlement process
through the transfer of densities among land uses of like designation.
c. Identify ecologically sensitive/unique habitats, including habitat linkages and
choke-points, within the City of Diamond Bar and prioritize their
acquisition/preservation/restoration as a preferred form of mitigation for future
development.
d. Collaborate with land trusts, joint-power authorities, and other conservation
groups to acquire and restore open space land through, but not limited to,
conservation easements and conservation plans.
• RC-I-2. As future parks are developed or open space is acquired/dedicated:
a. Preserve sensitive natural communities to maintain ecological integrity and
provide for passive recreation opportunities, such as hiking and bird-watching.
b. Site trails to avoid removal or fragmentation of sensitive natural communities
and to minimize erosion.
c. Prohibit the application of use of outdoor pesticide bait stations, or similar,
within 500 feet of any natural open space.
• RC-G-4. Provide recreational and cultural opportunities to the public in a
manner that maintains, restores, protects, and preserves sensitive natural
resources in the City of Diamond Bar and its Sphere of Influence.
• RC-I-12. Support and cooperate with efforts to identify and preserve
environmentally sensitive and strategically located canyon areas and hillsides
that serve as wildlife corridors and habitat linkages/choke points within
Diamond Bar and its Sphere of Influence, including components of the Puente-
Chino Hills Wildlife Corridor, Tres Hermanos Ranch, Tonner Canyon, and
Significant Ecological Area (SEA) 15, to provide regional connectivity, and to
sustain the ecological function of natural habitats and biological resources.
a. Establish appropriate resource protection overlays for ecologically sensitive
areas (see page 18 of this report).
b. Require adequate biological resources surveys as part of planning of
development proposed in any area with potential for special-status species
or sensitive natural communities to occur.
c. Discourage development in areas with identified sensitive natural resources,
natural geological features, and wildlife corridors and habitat linkages/choke
points, in order to preserve them in a natural state, unaltered by grading, fill,
or diversion activities (except as may be desirable for purposes of habitat
restoration and/or facilitation of wildlife movement).
34
d. Preserve and restore native woodlands in perpetuity, with a goal of no net
loss of existing woodlands, through compliance with Chapter 22.38 of the
Diamond Bar – Tree Preservation and Protection.
e. In the unincorporated Sphere of Influence, require that impacts to native oak
trees be treated in a manner consistent with Section 22.46.2100 of the
County of Los Angeles Code of Ordinances, except that in-lieu fees shall not
be accepted as mitigation for removal of regulated oaks. If replacement of
oaks is determined to be necessary, this should be conducted under a City-
administered Tree Mitigation Program developed in consultation with a
qualified biologist and Certified Arborist or Certified Urban Forester to
establish a to ensure that replacement trees are planted on public property
in areas that (a) shall not impact any existing sensitive habitat areas; (b) are
appropriate for the long-term survival of native trees planted as mitigation;
and (c) shall be maintained and preserved by the city, in perpetuity, as
natural open space for the mitigation trees and any associated understory
species deemed appropriate to provide valuable woodland habitat.
f. For development proposed adjacent to natural open space, require use of
highly fire-resistant building materials and methods, which minimize fuel
modification treatments.
g. In areas adjacent to natural open space, require use of highly fire-resistant
building materials and architecture for public safety and to minimize
requirements for damaging fuel modification treatments.
h. Fuel modification adjacent to natural open spaces should employ
exclusively native plant species approved for use in fuel modification zones,
which provide important habitat for native wildlife and minimize ongoing
irrigation and disturbance of the exterior slopes, reducing the potential for
exotic ants and weeds to become established on the site and then spread to
nearby natural open space areas.
• RC-I-28.5. Conserve natural open spaces, biological resources, and vegetation,
recognizing their roles in the reduction and mitigation of air pollution impacts,
and the promotion of carbon sequestration.
LITERATURE CITED
Allen, L. W., and Los Angeles County Sensitive Bird Species Working Group. 2009. Los Angeles County’s
Sensitive Bird Species. Western Tanager 75(3):E1–E11.
City of Diamond Bar and Diamond Bar Historical Society. 2014. Images of America, Diamond Bar. Arcadia
Publishing, Charleston, South Carolina.
Conservation Biology Institute. 2005. Maintaining Ecological Connectivity Across the “Missing Middle” of
the Puente-Chino Hills Wildlife Corridor. Encinitas, CA.
https://d2k78bk4kdhbpr.cloudfront.net/media/reports/files/pcmissingmiddle.pdf
35
Dyett & Bhatia. 2017. City of Diamond Bar General Plan Update, Existing Conditions Report – Volume III.
Redline draft dated February 21, 2017, prepared for City of Diamond Bar.
Los Angeles County, Dept. of Regional Planning. 2014. Los Angeles County Oak Woodlands Conservation
Management Plan Guide. Report dated March 18, 2014.
http://planning.lacounty.gov/assets/upl/project/oakwoodlands_conservation-management-plan-
guide.pdf
Los Angeles County Oak Woodlands Habitat Conservation Strategic Alliance. 2011. Los Angeles County
Oak Woodlands Conservation Management Plan. Report dated May 2011.
http://file.lacounty.gov/SDSInter/bos/bc/162273_official_20110620_oak-woodlands.pdf
Lower San Gabriel River Watershed Group. 2015. Lower San Gabriel River Watershed Management
Program.
https://www.waterboards.ca.gov/rwqcb4/waterissues/programs/stormwater/municipal/watershedman
agement/sangabriel/lowersangabriel/LowerSGRiverFinalWMP.pdf
Neal, S. 2011. Brea History – the Brea Creek. Brea Historical Society Brea Museum & Heritage Center.
Sage Environmental Group. 2012. Affordable Housing Land Use and Zoning Designation Project, Biological
Survey Report. Report dated August 2012 prepared for City of Diamond Bar.
Sheng, J. and J. P. Wilson. 2008. The Green Visions Plan for 21st Century Southern California. 16.
Watershed Assets Assessment Report. University of Southern California GIS Research Laboratory
and Center for Sustainable Cities, Los Angeles, CA.
U.S. Army Corps of Engineers. 1991. Los Angeles County Drainage Area Review, Final Feasibility Study,
Interim Report and Environmental Impact Statement. Vandergast, A. G., A. J. Bohonak, D. B.
Weissman, and R. N. Fisher. 2006. Understanding the genetic effects of recent habitat fragmentation
in the context of evolutionary history: Phylogeography and landscape genetics of a southern
California endemic Jerusalem cricket (Orthoptera: Stenopelmatidae: Stenopelmatus). Molecular
Ecology 16:977–92.
H AMILTON B IOLOGICAL
February 20, 2019
Greg Gubman
Director of Community Development
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
SUBJECT: APPENDIX A TO OPEN SPACE AND CONSERVATION ELEMENT
DIAMOND BAR GENERAL PLAN UPDATE
METHODS AND TECHNICAL INFORMATION
Dear Mr. Gubman,
A consortium of Diamond Bar residents retained Hamilton Biological, Inc., (hereafter
“Hamilton Biological”) to prepare an Open Space and Conservation Element for the
City of Diamond Bar (hereafter the “City”) to consider incorporating into a forthcoming
update to its General Plan. This letter describes the methods used to prepare the pro-
posed Open Space and Conservation Element, and provides technical biological infor-
mation that underpins the report’s findings and recommendations.
METHODS
Literature Review
As an initial step, Robert Hamilton, President of Hamilton Biological, reviewed the Bio-
logical Resources section of Dyett & Bhatia (2017) and a partial rough draft of an Open
Space and Conservation Element prepared by Cooper Ecological Monitoring, Inc. Mr.
Hamilton also reviewed a biological report prepared by Sage Environmental Group
(2012) for an Affordable Housing Land Use and Zoning Designation Project proposed
on a site covering 78 acres in the northeastern part of the City, near Diamond Ranch
High School.
Special-status species with potential to occur in Diamond Bar and adjacent areas were
identified through review of the California Natural Diversity Database (2018a, 2018b,
2018c) and searches of eBird (https://ebird.org); California Native Plant Society’s
Online Inventory of Rare and Endangered Plants (www.rareplants.cnps.org); review of
the list of Los Angeles County’s Sensitive Bird Species (Allen et al. 2009;
https://losangelesaudubon.org/images/stories/pdf/WesternTanager_pdfs/Vol.75/vo
l75no03jan-feb2009.pdf); the Consortium of California Herbaria web page
(www.ucjeps.berkeley.edu/consortium); Sage Environmental Group (2012); Dyett &
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 2 of 9
Bhatia (2017); and the online Flora of the Skyline Trail, Puente Hills, Los Angeles County
(Muns, B., 1982; http://tchester.org/plants/muns/pr/skyline_trail.html).
Mapping and Field Surveys
Robert A. Hamilton mapped the natural open space areas throughout the City and its
Sphere of Influence using Google Earth Pro. Potential habitat linkages and/or choke-
points for wildlife movement were identified by examination of aerial imagery. Mr.
Hamilton conducted reconnaissance field surveys on January 4 and 8, and February 4
and 8, 2019, to field-check the mapping and to observe the existing conditions through-
out most of Diamond Bar. Mr. Hamilton has visited the portion of Tonner Canyon that
lies within the City’s Sphere of Influence on numerous occasions in recent years, and
thus has viewed the natural resources found in that part of the study area, as well.
Classification of Natural Communities
Since the mid-1990s, CDFW and its partners, including the California Native Plant
Society (CNPS), have been working on classifying vegetation types using standards
embodied in the Survey of California Vegetation, which comply with the National
Vegetation Classification Standard (NVCS; http://usnvc.org/explore-classification/). The
NVCS is a hierarchical classification, with the most granular level being the Association.
Associations are grouped into Alliances, Alliances into Groups, and upward, as follows:
Formation Class > Formation Subclass > Formation > Division > Macrogroup > Group
> Alliance > Association. For purposes of this Open Space and Conservation Element,
Natural Communities are generally classified at the more generalized levels (e.g.,
Group), but for environmental review of specific projects in Diamond Bar, Natural
Communities should be classified and mapped at the more detailed Alliance or
Association level.
The method recommended by CDFW for classifying Natural Communities and
conducting CEQA review reads as follows:
• Identify all Natural Communities within the project footprint using the best means
possible, for example, keying them out in the Manual of California Vegetation,
Second Edition (Sawyer et al. 2009) or in classification or mapping reports from the
region, available on VegCAMP’s Reports and Maps page.
• Refer to the current standard list of Natural Communities to determine if any of
these types are ranked Sensitive (S1-S3 rank); if so, see CEQA Guidelines checklist
at IVb.
• Other considerations when assessing potential impacts to Sensitive Natural
Communities from a project include:
1. Compliance with state and federal wetland and riparian policies and codes,
as certain Natural Communities are restricted to wetlands or riparian set-
tings.
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 3 of 9
2. Compliance with the Native Plant Protection Act and the state and federal
Endangered Species Acts, as some Natural Communities either support rare
species or are defined by the dominance or presence of such species.
3. Compliance with CEQA Guidelines Section 15065(a), which mandates
completion of an EIR if a project would threaten to eliminate a plant com-
munity.
4. Compliance with local regional plans, regulations, or ordinances that call
for consideration of impacts to Natural Communities.
5. Vegetation types that are not on the state’s sensitive list but that may be con-
sidered rare or unique to the region under CEQA Guidelines Section
15125(c).
• If a Natural Community in the project area has not previously been described, it
may be a rare type. In this case, please contact VegCAMP (Todd Keeler-Wolf or
Diana Hickson) about documenting the Natural Community.
• If there are Sensitive Natural Communities on your project site and you need
guidance, contact the appropriate regional staff person through the local CDFW
Regional Office to discuss potential project impacts; these staff have local
knowledge and context.
Identifying Sensitive Natural Communities
The California Department of Fish and Wildlife (CDFW), at its VegCAMP page, pro-
vides guidance on appropriate methods for “Addressing Sensitive Natural Communi-
ties in Environmental Review”:
https://www.wildlife.ca.gov/Data/VegCAMP/Natural-Communities#sensitive%20natural%20communities
The State’s guidance consists of the following steps:
• Identify all Natural Communities within the project footprint using the best means
possible, for example, keying them out in the Manual of California, Second Edition
(Sawyer et al. 2009) or in classification or mapping reports from the region,
available on VegCAMP’s Reports and Maps page.
• Refer to the current standard list of Natural Communities to determine if any of
these types are ranked Sensitive (S1-S3 rank); if so, see CEQA Guidelines checklist
at IVb.
• Other considerations when assessing potential impacts to Sensitive Natural
Communities from a project include:
o Compliance with state and federal wetland and riparian policies and codes,
as certain Natural Communities are restricted to wetlands or riparian set-
tings.
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 4 of 9
o Compliance with the Native Plant Protection Act and the state and federal
Endangered Species Acts, as some Natural Communities either support rare
species or are defined by the dominance or presence of such species.
o Compliance with CEQA Guidelines Section 15065(a), which mandates
completion of an EIR if a project would threaten to eliminate a plant com-
munity.
o Compliance with local regional plans, regulations, or ordinances that call
for consideration of impacts to Natural Communities.
• Vegetation types that are not on the State’s sensitive list but that may be considered
rare or unique to the region under CEQA Guidelines Section 15125(c).
• If a Natural Community in the project area has not previously been described, it
may be a rare type. In this case, please contact VegCAMP (Todd Keeler-Wolf or
Diana Hickson) about documenting the Natural Community.
• If there are Sensitive Natural Communities on your project site and you need guid-
ance, contact the appropriate regional staff person through the local CDFW Re-
gional Office to discuss potential project impacts; these staff have local knowledge
and context.
• The Department’s document, Protocols for Surveying and Evaluating Impacts to
Special Status Native Plant Populations and Natural Communities (PDF) provides
information on reporting.
The City of Diamond Bar should employ the above-described methods to ensure the
thoroughness and adequacy of CEQA documentation completed within the City and its
Sphere of Influence.
Important Considerations for Oak Woodlands
As of January 2005, California Public Resources Code Section 21083.4 (2004 Senate Bill
1334) requires that when a county is determining the applicability of CEQA to a project,
it must determine whether that project “may result in a conversion of oak woodlands
that will have a significant effect on the environment.” If such effects (either individual
impacts or cumulative) are identified, the law requires that they be mitigated. Accepta-
ble mitigation measures include, but are not limited to, conservation of other oak wood-
lands through the use of conservation easements and planting replacement trees, which
must be maintained for seven years.
Diamond Bar’s Sphere of Influence, south of the city limits, lies within unincorporated
Los Angeles County, and thus the City’s General Plan should acknowledge that the
County of Los Angeles Department of Regional Planning issued in 2014 an Oak Wood-
lands Conservation Management Plan Guide1, with three important objectives: (1) pri-
1 http://planning.lacounty.gov/assets/upl/project/oakwoodlands_conservation-management-plan-guide.pdf
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 5 of 9
oritize the preservation of oak woodlands; (2) promote conservation by integrating oak
woodlands into the development process in a sustainable manner; and (3) effectively
mitigate the loss of oak woodlands.
ADVERSE EFFECTS OF DEVELOPMENT ON PRESERVED HABITAT AREAS
One purpose of a General Plan is to guide future development so as to minimize ad-
verse effects upon sensitive Natural Communities and declining native plant and wild-
life populations, to the extent feasible. Beyond the outright removal of natural areas,
which obviously impacts natural resources, development projects inevitably degrade
and fragment habitats along the urban/wildland interface. Such secondary, or indirect,
impacts have been subject to intensive study in recent years, to (a) understand and
characterize them, and (b) develop strategies for minimizing and mitigating them. The
following discussions, including citations from the scientific literature, provide the basis
for the General Plan’s land-use policies concerning edge and fragmentation effects.
Urbanization typically includes residential, commercial, industrial, and road-related
development. At the perimeter of the built environment is an area known as the ur-
ban/wildland interface, or “development edge.” Edges are places where natural com-
munities interface, vegetation or ecological conditions within natural communities in-
teract (Noss 1983), or patches with differing qualities abut one another (Ries and Sisk
2004). “Edge effects” are spillover effects from the adjacent human-modified matrix
that cause physical gradients in light, moisture, noise, etc. (Camargo and Kapos 1995;
Murcia 1995, Sisk et al. 1997) and/or changes in biotic factors such as predator commu-
nities, density of human-adapted species, and food availability (Soulé et al. 1988;
Matlack 1994; Murcia 1995; Ries and Sisk 2004). Loss, degradation, and fragmentation of
habitat due to urbanization are the most pervasive threats to biodiversity in southern
California (Soulé 1991). Edge-related impacts may include:
• Introduction/expansion of invasive exotic vegetation carried in from vehicles, peo-
ple, animals or spread from backyards or fuel modification zones adjacent to
wildlands.
• Increased frequency and/or severity of fire as compared to natural fire cycles or in-
tensities.
• Companion animals (pets) that often act as predators of, and/or competitors with,
native wildlife.
• Creation and use of trails that often significantly degrade intact ecosystems through
such changes as increases in soil disturbance, vegetation damage, and noise.
• Introduction of or increased use by exotic animals which compete with or prey on
native animals.
• Pesticide exposure can be linked to cancer, endocrine disruption, reproductive ef-
fects, neurotoxicity, kidney and liver damage, birth defects, and developmental
changes in a wide range of species, from insects to top predators.
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 6 of 9
• Influence on earth systems and ecosystem processes, such as solar radiation, soil
richness and erosion, wind damage, hydrologic cycle, and water pollution that can
affect the natural environment.
Any of these impacts, individually or in combination, can result in the effective loss or
degradation of habitats used for foraging, breeding or resting, with concomitant effects
on population demographic rates of sensitive species.
The coastal slope of southern California is among the most highly fragmented and ur-
banized regions in North America (Atwood 1993). Urbanization has already claimed
more than 90 percent of the region’s coastal sage scrub habitat, 99 percent of the coastal
prairie, and 95 percent of the vernal pools (McCaull 1994; Mattoni & Longcore 1997;
Bauder & McMillan 1998). A review of studies completed by Harrison and Bruna (1999)
identified a general pattern of reduction of biological diversity in fragmented habitats
compared with more intact ones, particularly with regard to habitat specialists. While
physical effects associated with edges were predominant among species impacts, they
found evidence for indirect effects including altered ecological interactions. Fletcher et
al. (2007) found that distance from edge had a stronger effect on species than did habitat
patch size, but they acknowledged the difficulty in separating those effects empirically.
Many southern California plant and animal species are known to be sensitive to frag-
mentation and edge effects; that is, their abundance declines with fragment size and
proximity to an edge (Wilcove 1985; Soulé et al. 1992; Bolger et al. 1997a,b; Suarez et al.
1998; Burke and Nol 2000).
Wildlife populations are typically changed in proximity to edges, either by changes in
their demographic rates (survival and fecundity), or through behavioral avoidance of or
attraction to the edge (Sisk et al. 1997; Ries and Sisk 2004). For example, coastal sage
scrub areas within 250 meters of urban edges consistently contain significantly less bare
ground and more coarse vegetative litter than do more “intermediate” or “interior” are-
as, presumably due increased human activity/disturbance of the vegetation structure
near edges (Kristan et al. 2003). Increases in vegetative litter often facilitate growth of
non-native plants (particularly grasses), resulting in a positive feedback loop likely to
enhance plant invasion success (Wolkovich et al. 2009). In another coastal southern Cali-
fornia example, the abundance of native bird species sensitive to disturbance is typical-
ly depressed within 200 to 500 meters (650 to 1640 feet) of an urban edge, and the abun-
dance of disturbance-tolerant species is elevated up to 1000 meters (3280 feet) from an
urban edge, depending on the species (Bolger et al. 1997a).
Habitat fragmentation is usually defined as a landscape scale process involving habitat
loss and breaking apart of habitats (Fahrig 2003). Habitat fragmentation is among the
most important of all threats to global biodiversity; edge effects (particularly the diverse
physical and biotic alterations associated with the artificial boundaries of fragments) are
dominant drivers of change in many fragmented landscapes (Laurance and Bierregaard
1997; Laurance et al. 2007).
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 7 of 9
Fragmentation decreases the connectivity of the landscape while increasing both edge
and remnant habitats. Urban and agricultural development often fragments wildland
ecosystems and creates sharp edges between the natural and human-altered habitats.
Edge effects for many species indirectly reduce available habitat use or utility in sur-
rounding remaining areas; these species experience fine-scale functional habitat losses
(e.g., see Bolger et al. 2000; Kristan et al. 2003; Drolet et al. 2016). Losses of coastal sage
scrub in southern California have increased isolation of the remaining habitat fragments
(O’Leary 1990) and led to calls to preserve and restore landscape connectivity to permit
long-term persistence of native species with low vagility (e.g., Vandergast et al. 2006).
Fragmentation has a greater relative negative impact on specialist species (e.g., coastal
populations of the Cactus Wren, Campylorhynchus brunneicapillus) that have strict vege-
tation structure and area habitat requirements (Soulé et al. 1992). Specialist species have
an increased risk of extirpation in isolated habitat remnants because the specialized
vegetative structures and/or interspecific relationships on which they depend are more
vulnerable to disruption in these areas (Vaughan 2010). In studies of the coastal sage
scrub and chaparral systems of coastal southern California, fragment area and age (time
since isolation) were the most important landscape predictors of the distribution and
abundance of native plants (Soulé et al. 1993), scrub-breeding birds (Soulé et al. 1988;
Crooks et al. 2001), native rodents (Bolger et al. 1997b), and invertebrates (Suarez et al.
1998; Bolger et al. 2000).
Edge effects that emanate from the human-dominated matrix can increase the extinction
probability of isolated populations (Murcia 1995; Woodroffe and Ginsberg 1998). In
studies of coastal sage scrub urban fragments, exotic cover and distance to the urban
edge were the strongest local predictors of native and exotic carnivore distribution and
abundance (Crooks 2002). These two variables were correlated, with more exotic cover
and less native shrub cover closer to the urban edge (Crooks 2002).
The increased presence of human-tolerant “mesopredators” in southern California rep-
resents an edge effect of development; they occur within the developed matrix and are
thus more abundant along the edges of habitat fragments, and they are effective preda-
tors on birds, bird nests, and other vertebrates in coastal sage scrub and chaparral sys-
tems and elsewhere (Crooks and Soulé 1999). The mammalian carnivores more typically
detected in coastal southern California habitat fragments are resource generalists that
likely benefit from the supplemental food resources (e.g., garden fruits and vegetables,
garbage, direct feeding by humans) associated with residential developments. As a re-
sult, the overall mesopredator abundance, of such species as raccoons (Procyon lotor),
opossums (Didelphis virginiana), and domestic cats (Felis catus), increases at sites with
more exotic plant cover and closer to the urban edge (Crooks 2002). Although some
carnivores within coastal sage scrub fragments seem tolerant of disturbance, many
fragments have (either actually or effectively) already lost an entire suite of predator
species, including mountain lion, bobcats (Lynx rufus), spotted skunks (Spilogale gracilis),
long-tailed weasels (Mustela frenata), and badgers (Taxidea taxus) (Crooks 2002). Most
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 8 of 9
“interior” sites within such fragments are still relatively near (within 250 meters of) ur-
ban edges (Crooks 2002).
Fragmentation generally increases the amount of edge per unit land area, and species
that are adversely affected by edges can experience reduced effective area of suitable
habitat (Temple and Cary 1988), which can lead to increased probability of extirpa-
tion/extinction in fragmented landscapes (Woodroffe and Ginsberg 1998). For example,
diversity of native bees (Hung et al. 2015) and native rodents (Bolger et al. 1997b) is
lower, and decomposition and nutrient cycling are significantly reduced (Treseder and
McGuire 2009), within fragmented coastal sage scrub ecosystems as compared to larger
core reserves. Similarly, habitat fragmentation and alterations of sage scrub habitats
likely have reduced both the genetic connectivity and diversity of coastal-slope popula-
tions of the Cactus Wren in southern California (Barr et al. 2015). Both Bell’s Sparrows
(Artemisiospiza belli) and California Thrashers (Toxostoma redivivum) show strong evi-
dence of direct, negative behavioral responses to edges in coastal sage scrub; that is,
they are edge-averse (Kristan et al. 2003), and California Thrashers and California Quail
(Callipepla californica) were found to be more vulnerable to extirpation with smaller
fragment size of the habitat patch (Bolger et al. 1991), demonstrating that both behav-
ioral and demographic parameters can be involved. Other species in coastal sage scrub
ecosystems, particularly the Cactus Wren and likely the California Gnatcatcher and San
Diego Pocket Mouse (Chaetodipus fallax), are likely vulnerable to fragmentation, but for
these species the mechanism is likely to be associated only with extirpation vulnerabil-
ity from habitat degradation and isolation rather than aversion to the habitat edge (Kris-
tan et al. 2003). Bolger (et al. 1997b) found that San Diego coastal sage scrub and chapar-
ral canyon fragments under 60 acres that had been isolated for at least 30 years support
very few populations of native rodents, and they suggested that fragments larger than
200 acres in size are needed to sustain native rodent species populations.
The penetration of exotic species into natural areas can reduce the effective size of a re-
serve in proportion to the distance they penetrate within the reserve: Argentine Ants
serve as an in-depth example of edge effects and fragmentation. Spatial patterns of Ar-
gentine Ant abundance in scrub communities of southern California indicate that they
are likely invading native habitats from adjacent developed areas, as most areas sam-
pled greater than 200 to 250 meters from an urban edge contained relatively few or no
Argentine Ants (Bolger 2007, Mitrovich et al. 2010). The extent of Argentine Ant inva-
sions in natural environments is determined in part by inputs of urban and agricultural
water run off (Holway and Suarez 2006). Native ant species were more abundant away
from edges and in areas with predominately native vegetation. Post-fragmentation edge
effects likely reduce the ability of fragments to retain native ant species; fragments had
fewer native ant species than similar-sized plots within large unfragmented areas, and
fragments with Argentine ant-free refugia had more native ant species than those with-
out refugia (Suarez et al. 1998). They displace nearly all surface-foraging native ant spe-
cies (Holway and Suarez 2006) and strongly affect all native ant communities within
about 150 to 200 meters from fragment edges (Suarez et al. 1998; Holway 2005; Fisher et
al. 2002; Bolger 2007; Mitrovich et al. 2010). Argentine Ants are widespread in frag-
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 9 of 9
mented coastal scrub habitats in southern California, and much of the remaining poten-
tial habitat for Blainville’s Horned Lizards (Phrynosoma blainvillii) is effectively unsuita-
ble due to the penetration of Argentine ants and the subsequent displacement of the na-
tive ant species that Coastal Horned Lizards need as prey (Fisher et al. 2002). Invasion
of Argentine Ants into coastal sage scrub has also shown a strong negative effect on the
abundance of the gray shrew (Notiosorex crawfordi) (Laakkonen et al. 2001).
An evaluation by the U.S. Environmental Protection Agency (2008) concluded that each
of ten of the most common active ingredients in rodenticides “poses significant risks to
non-target wildlife when applied as grain-based bait products. The risks to wildlife are
from primary exposure (direct consumption of rodenticide bait) for all compounds and
secondary exposure (consumption of prey by predators or scavengers with rodenticide
stored in body tissues) from the anticoagulants.” Thus, the common practice of setting
out bait within or near natural areas can be expected to have adverse effects upon a
range of native wildlife species.
Finally, in the Santa Monica Mountains of Los Angeles County, populations of such na-
tive amphibians as the California newt (Taricha torosa) and California treefrog
(Pseudacris cadaverina) were found to decline with urbanization of as little as 8% of a
given watershed (Riley et al. 2005). Such faunal community changes appear to be relat-
ed to changes in physical stream habitat, such as fewer pool and more run habitats and
increased water depth and flow. These changes are associated with increased erosion
and with invasion by damaging exotic species, such as the red swamp crayfish (Procam-
barus clarkii).
CONCLUSION
I appreciate the opportunity to provide this technical informtion in support of the Open
Space and Conservation Element for the Diamond Bar General Plan. If you have ques-
tions, please call me at (562) 477-2181 or send e-mail to robb@hamiltonbiological.com.
Sincerely,
Robert A. Hamilton
President, Hamilton Biological, Inc.
316 Monrovia Avenue
Long Beach, CA 90803
562-477-2181
robb@hamiltonbiological.com
Attached: Literature Cited
Literature Cited, Appendix A to Open Space and Conservation Element, DBGP Hamilton Biological, Inc.
February 19, 2019 Literature Cited
LITERATURE CITED
Allen, L. W., and Los Angeles County Sensitive Bird Species Working Group. 2009. Los Angeles County’s
Sensitive Bird Species. Western Tanager 75(3):E1–E11.
Barr, K. R., B. E. Kus, K. L. Preston, S. Howell, E. Perkins, and A. G. Vandergast. 2015. Habitat fragmentation
in coastal southern California disrupts genetic connectivity in the Cactus Wren (Campylorhynchus brun-
neicapillus). Molecular Ecology 24:2349–2363.
Bauder, E. T., and S. McMillan. 1998. Current distribution and historical extent of vernal pools in southern
California and northern Baja California, Mexico. Pp. 56–70 in Ecology, Conservation and Management
of Vernal Pool Ecosystems (C. W. Witham, E. T. Bauder, D. Belk, W. R. Ferren Jr., and R. Ornduffm, edi-
tors). California Native Plant Society, Sacramento.
Bolger, D. T. 2007. Spatial and temporal variation in the Argentine ant edge effect: implications for the
mechanism of edge limitation. Biological Conservation 136:295–305.
Bolger, D. T., A. C. Alberts, and M. E. Soulé. 1991. Occurrence patterns of bird species in habitat fragments:
sampling, extinction, and nested species subsets. The American Naturalist 137(2):155–166.
Bolger, D. T., T. A. Scott, and J. T. Rotenberry. 1997a. Breeding bird abundance in an urbanizing landscape
in coastal southern California. Conservation Biology 11(2):406–421.
Bolger, D. T., A. C. Alberts, R. M. Sauvajot, P. Potenza, C. McCalvin, D. Tran, S. Mazzoni, and M. E. Soulé.
1997b. Response of rodents to habitat fragmentation in coastal southern California. Ecological Applica-
tions 7(2):552–563.
Bolger, D. T., A. V. Suarez, K. R. Crooks, S. A. Morrison, and T. J. Case. 2000. Arthropods in urban habitat
fragments in southern California: area, age, and edge effects. Ecological Applications 10(4):1230-1248.
Burke, D. M., and E. Nol. 2000. Landscape and fragment size effects on reproductive success of forest-
breeding birds in Ontario. Ecological Applications 10(6):1749–1761.
California Natural Diversity Database. 2018a. Special Vascular Plants, Bryophytes, and Lichens List. Current
list of vegetative taxa considered to be rare, threatened, endangered, or otherwise “sensitive” by the
State of California. List dated November 2018.
California Natural Diversity Database. 2018b. Special Animals List. Current list of wildlife taxa considered to
be rare, threatened, endangered, or otherwise “sensitive” by the State of California. List dated November
2018.
California Natural Diversity Data Base. 2018c. Rarefind data accessed online on July 6, 2018, for the U.S.
Geologic Survey’s Yorba Linda, San Dimas, Ontario, and Prado Dam 7.5’ topographic quadrangles.
Camargo, J. L. C., and V. Kapos. 1995. Complex edge effects on soil moisture and microclimate in central
Amazonian forest. Journal of Tropical Ecology 11(2):205–221.
Conservation Biology Institute. 2005. Maintaining Ecological Connectivity Across the “Missing Middle” of
the Puente-Chino Hills Wildlife Corridor. Encinitas, CA.
https://d2k78bk4kdhbpr.cloudfront.net/media/reports/files/pc_missing_middle.pdf
Crooks, K. R. 2002. Relative sensitivities of mammalian carnivores to habitat fragmentation. Conservation
Biology 16(2):488–502.
Literature Cited, Appendix A to Open Space and Conservation Element, DBGP Hamilton Biological, Inc.
February 19, 2019 Literature Cited
Crooks, K. R., and M. E. Soulé. 1999. Mesopredator release and avian extinctions in a fragmented system.
Nature 400:563–566.
Crooks, K. R., A. V. Suarez, D. T. Bolger, and M. E. Soulé. 2001. Extinction and colonization of birds on
habitat islands. Conservation Biology 15(1):159–172.
Drolet, A., C. Dussault, and S. D. Côté. 2016. Simulated drilling noise affects the space use of a large terres-
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Diamond Bar Preservation Foundation
664 Armitos Place
Diamond Bar, CA 91765-1863
501c3, Non-profit, for Public Benefit
Dr. Chia Teng, President
Oct. 31, 2019
To: City of Diamond Bar, Senior Planner Ms. Grace Lee
RE: Comments, General Plan 2040 and DEIR
Dear Ms. Lee,
I am grateful to comment on the City of Diamond Bar, general plan and DEIR.
Here are my main observation and concerns.
1. A failed mitigation project, Millennium Diamond Road Partners, has gripped
our community with doubt that the Lead Agency has demonstrated CEQA
adherence or understanding to a due diligent process and best practice.
Today, we see numerous permit violations and apparently no relief to the
failed mitigation at Bonelli Park.
Question: How will the DEIR monitoring and mitigation plans assure the public of
efficiency to avoid such future failure? The language in the document is not specific.
Will there be a training manual, educating the public how dependable city procedures
are to protect the community from environmental damage, and loss?
2. Mitigation options in the DEIR suggest there is a successful mitigation possible
by replacing the removal of old growth, mature oak trees (which sequester 55
thousand pounds of carbon, per tree each year, with young oak trees. How is
this possible if science teaches oaks must mature to at least 50 years old to
perform carbon capture of that level. Meaning, it would take fi fty years to
restore the lost ecosystem services provided by oaks – and especially if the
oaks were mitigated “off-site” and perhaps far away. The local community is
at a loss of the benefits, so mitigation can truly not be achieved. What does
the city say about this realization? (see oak woodland conservation guide)
3. Enclosed is a picture of the southern oak riparian woodland/walnut woodland
that was destroyed by scorch earth grading (December 2017) violating permits
and causing a city issued Cease/Desist. Why does the DEIR “vegetation
community” map depict walnut woodlands only, in this area? Notice my
picture is a strand of riparian oak woodland which survived rogue bulldozing.
Please tell me, where are the walnut trees. Where are they? Why is this
habitat omitted and misrepresented in the Resource Conservation figure 5.2?
4. The oak woodland preservation language in the DEIR “sounds” good, but it
appears there is little solid commitment to conservation. City wording feels
tentative and sounds vague. Will the city consider abiding by the 2011 and
Diamond Bar Preservation Foundation
664 Armitos Place
Diamond Bar, CA 91765-1863
501c3, Non-profit, for Public Benefit
Dr. Chia Teng, President
2014 Los Angeles County Oak Woodland Conservation Management Plan
Guide? If so, will the city depend on CalFIRE Urban Forestry leads to guide
preservation of oak woodlands in the city?
http://planning.lacounty.gov/assets/upl/project/oakwoodlands_conservation -
management-plan-guide.pdf
I was also disappointed the city council chose to affect an d change the general plan
and DEIR document, in special meetings Sept. 25 and Oct. 8th, while at the same time
it was out for Public Review (Sept. 14-Oct.31)
There were approximately 60 language changes processed . Were the members of the
public including stakeholders notified, other than meeting agendas posted on the
general plan website? Many of us had no idea what was happening unless we
attended the Sept 25 and Oct. 8th special meetings. How the lack of informing the
public comports with CEQA guidelines?
Millennium Diamond Road project, Diamond Bar, 2017. Oak woodland riparian, foreground.
Diamond Bar Preservation Foundation
664 Armitos Place
Diamond Bar, CA 91765-1863
501c3, Non-profit, for Public Benefit
Dr. Chia Teng, President
In conclusion, the efforts of the Diamond Bar Preservation Foundation and Alliance
aim to protect our community from suffering devastating environmental damage ever
again. We are also interested in habitat restoration and promoting native plant
landscapes, so to restore the California beauty our neighborhood is famous for and
that we cherish.
I am eager to learn how the city intends to impl ement better practices in preserving
the natural character of Diamond Bar.
Thank you for review my letter and material and answering my questions.
Sincerely ,
Dr. Chia Teng
President,
Attachments: Hamilton Biological Report & Map, attached
L.A. Oak Woodland Conservation Plan Guide link
http://planning.lacounty.gov/assets/upl/project/oakwoodlands_conservation-
management-plan-guide.pdf
Biological Resources Report
City of Diamond Bar
“This work is dedicated to the City of Diamond Bar, to its
residents --- especially the children.”
Dedicated & Funded by a consortium of Diamond Bar residents and:
Cover Photo by Diamond Bar Resident, Eraina Olson, 2019.
Photos for Resource Protection Recommendations, by Robert Hamilton 2019.
February, 2019
Biological Resources Report
City of Diamond Bar
Prepared By
Hamilton Biological, Inc.
Robert A. Hamilton, President
316 Monrovia Avenue
Long Beach, CA 90803
http://hamiltonbiological.com
February 25, 2019
TABLE OF CONTENTS
TABLE OF CONTENTS .................................................................................. II
INTRODUCTION .......................................................................................... 1
METHODS & TECHNICAL INFORMATION ........................................................... 2
VISIONS, GOALS, OBJECTIVES .......................................................................... 2
HISTORY & LAND USE ................................................................................... 5
SCENIC RESOURCES ....................................................................................... 5
HYDROLOGY/WATERWAYS ........................................................................ 6
DIAMOND BAR WATERSHEDS ......................................................................... 8
FLOODING ................................................................................................... 9
BIOLOGICAL RESOURCES ........................................................................... 9
NATURAL COMMUNITIES ................................................................................ 9
Annual and Perennial Grasslands, Vernal Pools/Seasonal Pools ............ 10
Coastal Sage Scrub, Cactus Scrub .......................................................... 10
Chaparral .............................................................................................. 11
Coast Live Oak Woodland, Savannah ................................................... 11
California Walnut Woodland, Savannah ............................................... 11
Riparian Scrub and Woodlands ............................................................. 12
Human-altered Habitats ........................................................................ 12
NATURAL OPEN SPACE AREAS ....................................................................... 12
RESOURCE PROTECTION RECOMMENDATIONS ................................................. 17
SENSITIVE RESOURCES .................................................................................. 19
Sensitive Natural Communities ............................................................. 20
Special-Status Species ........................................................................... 20
EFFECTS OF DEVELOPMENT ON BIOLOGICAL RESOURCES .................... 29
EDGE/FRAGMENTATION EFFECTS ON WILDLIFE MOVEMENT ............................... 30
Wildlife Movement Issues in the Puente-Chino Hills ............................. 30
NATURAL RESOURCE CONSERVATION POLICIES .................................... 32
GOALS AND POLICIES OF THE OPEN SPACE AND CONSERVATION ELEMENT ........... 32
LITERATURE CITED .................................................................................... 34
III
FIGURES
1: Waterways ............................................................................................. 6
2: Lower San Gabriel River Watershed ....................................................... 7
3a: Natural Open Space Areas, Part 1 ........................................................ 13
3b: Natural Open Space Areas, Part 2 ........................................................ 14
3c: Natural Open Space Areas, Part 3 ........................................................ 15
3d: Natural Open Space Areas, Part 4 ........................................................ 16
TABLES
A: Resource Protection Recommendations ................................................ 17
B: Special Status Species ........................................................................... 22
APPENDICES
A: Methods & Technical Information
1
INTRODUCTION
Hamilton Biological, Inc., was retained by a consortium of Diamond Bar residents to
prepare this biological resources report addressing the conservation and preservation of
sensitive biological resources in the City of Diamond Bar (City) and its Sphere of
Influence. It is intended that the City incorporate the information and analyses in this
report into the next update of its general plan, currently in preparation.
Sections 65302(d) and 65302(e) of the California Government Code states that a city’s
general plan shall include goals and policies for management of open spaces, including
natural lands and recreation areas. The Open Space Element addresses such categories
as preservation of natural resources and managed production of resources. The
Conservation Element addresses protection and maintenance of natural resources,
including soils, water, plants, wildlife, and mineral resources. Recognizing that the
subjects covered under the Open Space Element and Conservation Element
substantially overlap, Appendix 1 to the California Government Code allows these two
elements to be combined in one section of the General Plan.
The Open Space and Conservation Element identifies and describes the irreplaceable
biotic resources that make up the natural environment that people rely upon for
breathable air, clean water, viable populations of native plants and wildlife, and the
natural beauty that pervades and defines Diamond Bar. The Open Space and
Conservation Element guides city decision-makers and the public in their efforts to take
the natural world into account during deliberations over development proposals, as
required to realize the overall vision laid out in the General Plan.
The Open Space and Conservation Element guides the development and
implementation of programs involving conservation of open space, biological
resources, visual resources, and parks and recreation. Approaches for managing
environmental impacts are identified, with particular emphasis on contributing to
achievement of the General Plan’s stated goals, including:
• Create and retain an open space system which will conserve natural resources,
preserve scenic beauty, promote a healthy community atmosphere, provide open
space for outdoor recreation, and protect the public safety.
• Identify limits on the natural resources needed to support urban and rural
development within the City and its Sphere of Influence, and ensure that those
resources are used wisely and not abused.
• Provide a park, recreation and open space system which enhances the livability of
urban and suburban areas by providing parks for residential neighborhoods;
preserving significant natural, scenic, and other open space resources; and meeting
the open space and recreational needs of Diamond Bar residents.
2
Methods & Technical Information
Please refer to Appendix A, which describes the methods for preparing this biological
resources report, as well as providing technical information that underpins the
analyses, conclusions, and policies contained herein.
Visions, Goals, Objectives
The General Plan identifies “a strongly held goal among the residents to maintain and
protect the distinctive physical attributes of Diamond Bar which make it a desirable
place in which to live.” To achieve this overarching goal of safeguarding open spaces
and significant natural features, as well as retaining the City’s distinctive natural
character, the Open Space and Conservation Element focuses on supporting the
following visions, goals and objectives, building upon language contained in the
original 1995 General Plan:
• Vision 1. Retention of the rural/country living community character. There is a
strong, long-held goal among residents to maintain and protect the distinctive,
physical attributes of Diamond Bar which make it a desirable place in which to live,
through a careful balance of housing, businesses and services, public facilities, and
preservation of natural environmental resources.
• Vision 2. Preservation of open space. Significant privately and publicly owned
natural lands that remain in Diamond Bar and its 3,591-acre Sphere of Influence
support numerous rare species and perform important ecological functions. The
preservation of sensitive natural resources contributes to the goal of retaining the
City’s distinctive rustic character and offers unique educational and recreational
opportunities. The County of Los Angeles has identified the Sphere of Influence and
adjacent lands, some of which lie within the City, as Significant Ecological Area
(SEA) 15. SEA 15 is recognized as a major significant ecological asset to the
community. The City will play a proactive role in the preservation of SEA 15 by
assuring that extensive analysis and review precede any changes from its current
uses and possibilities.
o Goal 1. Consistent with the Vision Statement, maintain a mix of land uses
which enhance the quality of life of Diamond Bar residents, providing a
balance of development and preservation of significant open space areas to
assure both economic viability and retention of distinctive natural features of
the community.
§ Objective 1.1 Establish a land use classification system to guide the
public and private use of land within the City and its Sphere of
Influence.
§ Objective 1.2 Preserve and maintain the quality of existing residential
neighborhoods while offering a variety of housing opportunities,
including mixed land uses.
3
§ Objective 1.3 Designate adequate land for retail and service
commercial, professional services, and other revenue generating uses
in sufficient quantity to meet the City’s needs.
§ Objective 1.4 Designate adequate land for educational, cultural,
recreational, and public service activities to meet the needs of
Diamond Bar residents.
§ Objective 1.5 Maintain a feeling of open space within the community
by identifying and preserving an adequate amount of open land.
§ Objective 1.6 Consistent with the Vision Statement, provide flexibility
in the planning of new development as a means of encouraging
superior land use by means such as open space and public amenities.
o Goal 2. Consistent with the Vision Statement, manage land use with respect
to the location, density and intensity, and quality of development. Maintain
consistency with the capabilities of the City and special districts to provide
essential services which achieve sustainable use of environmental and
manmade resources.
§ Objective 2.1 Promote land use patterns and intensities which are
consistent with the Resource Management Element and Circulation
Element.
§ Objective 2.2 Maintain an organized pattern of land use which
minimizes conflicts between adjacent land uses.
§ Objective 2.3 Ensure that future development occurs only when
consistent with the availability and adequacy of public services and
facilities.
o Goal 3. Consistent with the Vision Statement, maintain recognition within
Diamond Bar and the surrounding region as being a community with a well-
planned and aesthetically pleasing physical environment.
§ Objective 3.1 Create visual points of interest as a means of highlighting
community identity.
§ Objective 3.2 Ensure that new development, and intensification of
existing development, yields a pleasant living, working, or shopping
environment, and attracts interest of residents, workers, shoppers, and
visitors as the result of consistent exemplary design.
§ Objective 3.3 Protect the visual quality and character of remaining
natural areas, and ensure that hillside development does not create
unsafe conditions.
4
o Goal 4. Consistent with the Vision Statement, encourage long-term and
regional perspectives in local land use decisions, but not at the expense of
the Quality of Life for Diamond Bar residents.
§ Objective 4.1 Promote and cooperate in efforts to provide reasonable
regional land use and transportation/circulation planning programs.
o Goal 5. Consistent with the Vision Statement, recognize that oak trees, oak
woodlands, and associated habitats have intrinsic aesthetic, environmental,
ecological, wildlife, and economic values; that conservation of oak-
dominated landscapes is important to the health, safety and general welfare
of the citizens of Diamond Bar1; that that the General Plan must contain
adequate policies to protect the oak habitats from unnecessary damage,
removal or destruction; that native oak trees should be planted, where
appropriate, to enhance or restore damaged or degraded oak woodland
habitats and mitigate unavoidable losses.
§ Objective 5.1 Protect and extend the diversity of oak woodlands and
associated habitats (defined as lands on which the majority of the trees
are of the genus Quercus) through site design and land use regulations.
§ Objective 5.2 Reduce in scale, redesign, modify, or if no other
alternative exists, deny any project which cannot sufficiently mitigate
significant adverse impacts to oak woodlands.
§ Objective 5.3 Encourage property owners to establish Open Space
Easements or deed restrictions for areas containing oak woodlands, and
to allow access to enable scientific study.
§ Objective 5.4 Encourage concentration of development on minimum
number of acres (density exemptions) in exchange for maximizing long
term open space.
§ Objective 5.5 As a mitigation option, allow as a condition of
development approval, restoration of any area of oak woodland that is
in a degraded condition, with the magnitude of restoration to be
commensurate with the scope of the project. This may include planting
of oak trees and removal of non-native species, with consideration for
long-term viability, management, and protection, and/or modification
of existing land uses. The object of habitat restoration shall be to
enhance the ecological function of the oak woodland and to restore it
to a condition where it can be self-sustaining through natural
occurrences such as fire, natural hydrological processes, etc.
1 Woodlands are defined as lands with tree cover of at least 10%, and oak woodlands exist where the
majority of trees are of the genus Quercus.
5
History & Land Use
Set within the Puente Hills of southeastern Los Angeles County, the City of Diamond
Bar covers 14.9 square miles. Neighboring cities include Walnut, Pomona, Industry, La
Puente, Rowland Heights, Brea, and Chino Hills. The region now occupied by Diamond
Bar was inhabited by the Kizh people until the mid-eighteenth century, when the
Spaniards settled in the area, establishing Mission San Gabriel in 1771 (City of Diamond
Bar and Diamond Bar Historical Society 2014; Housing element 2014). The land
experienced a series of ownership changes involving various land grants and purchases
(e.g., the Los Nogales Grant; purchases by Luz Linares, Vejar and Palomares, Louis
Phillip, Frederick E. Lewis II, William Bartholome), eventually growing into one of the
largest and respected ranches in southern California and gaining its name. This lasted
until 1956, during which two subsidiaries of Transamerica Corporation (Christiana Oil
Corp and the Capital Oil Company) purchased the area, aiming to make it among the
first and largest master-planned community in Los Angeles County (City of Diamond
and Diamond Bar Historical Society 2014).
Despite initial intentions as a “master-planned” community, uncoordinated patterns of
development through the late twentieth century have introduced areas of incongruence,
such as single- and detached multi-family residential tracts being established alongside
limited commercial and other non-residential sections. Most suburban construction was
already established prior to the city’s incorporation in 1989, and commercial
development has continued expand within the city limit. A few blocks away from the
primary arterials (57 and 60 Freeways) the majority of retail and housing space is
largely concealed by the natural topography, contributing to Diamond Bar’s quiet,
semi-rural character and pleasant atmosphere.
Scenic Resources
Today, Diamond Bar is primarily a hillside residential community, composed of steep
and moderate sloping hills separated by ridges and flat plateaus. Although most of the
land was developed prior to the city’s incorporation, its remaining natural hillsides and
ridgelines provide a picturesque backdrop and strong visual ties to the area’s long
history of ranching. The views from these natural areas comprise powerful and
valuable scenic resources, adding ambiance and aesthetics that give Diamond Bar a
unique and compelling visual identity. In addition, views of trees, rolling hills and the
pine- and often snow-covered peaks of the San Gabriel Mountains are visible in the
distance from the 57 and 60 Freeways.
Planning decisions must recognize the existing aesthetic value of the city’s open space
as well as the external viewsheds of the surrounding region. These include the oak and
walnut wooded ridgelines, unique topography, and natural open spaces at the edges of
the community.
6
HYDROLOGY/WATERWAYS
Diamond Bar lies within of the San Gabriel River watershed, which is the largest
watershed in the drainage system of the San Gabriel Mountains at 441,000 acres (Lower
San Gabriel River Watershed Group 2015). The San Gabriel River is one of seven major
watersheds partly or completely within Los Angeles County. Most of the river lies in
southeastern Los Angeles County, but a portion of this watershed originates in northern
Orange County. The northern portion of the San Gabriel River, where it emerges from
the mountains, has retained some natural features, such as a sandy bottom and native
vegetation. Farther south, however, flood-control and channel stabilization measures
needed to accommodate intensive urbanization led to the river being lined with
concrete (US Army Corps of Engineers 1991; Neal 2011).
Water runs through Diamond Bar via numerous channels, creeks and canyons. A small
part of the northwestern part of the city drains to the San Gabriel River via the San Jose
Creek channel, which follows the route of Valley Boulevard west from Diamond Bar.
Most of Diamond Bar drains south to the San Gabriel River through the Coyote Creek
watershed (see Figure 1).
Figure 1, Waterways. Diamond Bar lies mostly within the watershed of Coyote Creek, but the northwestern
part of the city discharges to the west, through the San Jose Creek channel.
Source: National Hydrology Dataset. http://www.horizon-systems.com/nhdplus/NHDPlusV1download.php
7
Coyote Creek and San Jose Creek drain approximately 165 square miles and 83 square
miles, respectively, of highly urbanized commercial, residential, and industrial zones,
plus limited natural open space areas (Sheng & Wilson 2000, using Horton–Strahler
Stream Order).
In 2013, Diamond Bar joined 12 other cities and the Los Angeles County Flood Control
District to develop a Watershed Monitoring Program (WMP) and Coordinated
Integrated Monitoring Program (CIMP) to address the lower portion of the San Gabriel
River, which includes Reaches 1 and 2 of the San Gabriel River Watershed and portions
of Coyote Creek that originate from jurisdictions within Los Angeles County, including
the City of Diamond Bar. A small portion of Diamond Bar that discharges to the San
Gabriel River via San Jose Creek is also addressed by this CIMP. See Figure 2, below.
Figure 2, Lower San Gabriel River Watershed. Diamond Bar occupies the most northeasterly part of the
Lower San Gabriel River Coordinated Integrated Monitoring Program.
Source: Gateway Water Management Authority. https://gatewaywater.org/services/lsgr/
8
Diamond Bar Watersheds
Diamond Bar is served by four watersheds, all with some channelization/urbanization:
Tonner Canyon Creek, Diamond Bar Creek, Brea Canyon Creek, and San Jose Creek.
Each system supports riparian habitat that provides resources for protected/special-
status species. The following discussions describe each of these four drainage systems.
1. Tonner Canyon
With a watershed of 5,000 acres and very little development, Tonner Canyon ranks
among the most ecologically significant, unchannelized, largely undisturbed drainages
in the Los Angeles area (HFE 2018). Occupying parts of Los Angeles, San Bernardino
and Orange Counties, Tonner Canyon drains the southeastern side of Diamond Bar and
the northwestern side of the City of Chino Hills. The flow rate, controlled by natural
rills, gullies and washes, varies throughout the year. The canyon’s headwaters lie in a
bowl of low hills just south of Diamond Ranch High School. Roughly 1.4 miles
downstream, Grand Avenue cuts across the watershed, and just downstream from that
road crossing lies the small Arnold Reservoir. Below the reservoir’s dam, water flows
southwest through natural open space lands the City of Industry has purchased from
the Boy Scouts of America in recent years. After flowing for approximately a mile
through open, rolling hills, the creek then enters a narrower canyon, with steeper hills
on either side. At that point, the willow-, sycamore-, and oak-dominated riparian
vegetation becomes more developed. The creek flows another six miles south and west
to empty into Brea Creek, located near the 57 Freeway in the Coyote Creek drainage
basin of Orange County.
2. Diamond Bar Creek
Originating in the neighborhoods west of Diamond Ranch High School, Diamond Bar
Creek runs approximately 1.2 miles to the west, through Sycamore Canyon Park, and
then continues west of Golden Springs Road through Diamond Bar Golf Course, and
from there underneath the 57 and 60 Freeways, to a channel east of the freeway that is
tributary to San Jose Creek. The upper segment, from Leyland Drive through the
Sycamore Canyon Park, supports well-developed native sycamore/oak/willow
riparian woodlands. The segment passing through Diamond Bar Golf Course supports
broken, partially native riparian habitat.
3. Brea Canyon Creek
The southwestern part of Diamond Bar, including the “Brea Canyons” neighborhood
east of the 57 Freeway, drains south toward Coyote Creek via Brea Canyon Creek. Most
of this watershed is fully developed within the limits of Diamond Bar, but the
southernmost portion, near the terminus of Castle Rock Road, is a soft-bottomed
perennial creek that supports riparian vegetation.
9
4. San Jose Creek – South Branch/Fork
Located at Diamond Bar’s northwestern edge, the southern branch of San Jose Creek is
a concrete-lined, trapezoidal channel that collects a small portion of urban runoff that is
discharged north of the intersection of Sunset Crossing Road and North Diamond Bar
Blvd. Runoff collected from catch basins drains west toward San Jose Creek in the City
of Industry. At the eastern terminus of Back Lot Lane, in the City of Walnut, lies very
small patch of riparian vegetation consisting of native and exotic trees and shrubs.
Flooding
Flood insurance maps issued by the Federal Emergency Management Agency (FEMA)2,
showing areas that may be subject to flooding in 100-year storm events, indicate that
Diamond Bar is at low risk for major flood events. Only a limited section of the City,
located north of SR-60 (Reed Canyon Channel at Brea Canyon Road and Lycoming
Street) are a slightly elevated flood potential. Surrounding areas at potentially elevated
risk of flooding include locations north of the 57 Freeway (across Baker Parkway) and
an area covering roughly 2,000 acres near the border with Pomona.
An extensive system of concrete-lined drainages, many of which are independent of the
natural streambeds, carries runoff through the City. Areas considered to be at elevated
risk of flooding may require maintenance of drainage channels, which can include
removal of native wetland and riparian vegetation, to maintain the flow of water
through the stormwater system. Diamond Bar’s generally low risk for flooding allows
for native riparian vegetation to be retained in natural streambeds, which can develop
into important habitat for various wildlife species.
BIOLOGICAL RESOURCES
Natural Communities
This section briefly describes the Natural Communities (also known as “plant
communities” or “vegetation types”) that occur in Diamond Bar and its Sphere of
Influence (i.e., Tonner Canyon/Significant Ecological Area 15, located in
unincorporated Los Angeles County south of the city limits). The following discussions
of Natural Communities refer to Natural Open Space Areas in the City and its Sphere of
Influence, which are mapped subsequently (see Figures 3a–3d, starting on page 12).
Please refer also to Appendix A, which describes the State-recommended methods used
to classify Natural Communities for this report.
2 Los Angeles county Flood Zone Definitions, See http://dpw.lacounty.gov/wmd/floodzone/docs/FZDLegend.pdf
10
ANNUAL AND PERENNIAL GRASSLANDS, VERNAL POOLS/SEASONAL POOLS
Natural Open Space Areas: 1, 2, 6, 8, 10, 13, Sphere of Influence
The bottom of Tonner Canyon supports extensive grasslands. Most alliances of the
widespread “California annual grassland” are not identified as Sensitive by CDFW, as
they generally represent areas disturbed over long periods (e.g., by grazing) that no
longer support many native plant species. Among the most prevalent alliances in the
Diamond Bar area is “annual brome grassland.” Dominant species include ripgut
brome (Bromus diandrus), foxtail brome (Bromus madritensis ssp. rubens), wild oats (Avena
fatua), foxtail barley (Hordeum murinum ssp. leporinum), shortpod mustard (Hirschfeldia
incana), black mustard (Brassica nigra), wild radish (Raphanus sativus), Italian thistle
(Carduus pycnocephalus), and tocalote (Centaurea melitensis). Some disturbance-adapted
native forbs, such as common fiddleneck (Amsinckia intermedia) and arroyo lupine
(Lupinus succulentus), may also occur.
Areas of perennial grassland, distinguished by possessing non-trace cover of native
grasses, are identified as Sensitive by CDFW. As examples, the Nassella spp. – Melica
spp. herbaceous alliance is characterized by having at least 2–5 percent cover of native
needlegrass (Nassella spp.) or other native grasses3; and the Bromus carinatus – Elymus
glaucus herbaceous alliance has California brome (Bromus carinatus) characteristically
present, with native plants providing more than 10 percent relative cover.4 It is likely
that vernal pools/seasonal ponds occur in the site’s grasslands, and/or along dirt roads
that pass through other Natural Communities.
Special-status species known to occur in Diamond Bar’s grasslands, or that have
potential to occur there, include Catalina mariposa lily (Calochortus catalinae) small-
flowered microseris (Microseris douglasii ssp. platycarpha), Golden Eagle (Aquila
chrysaetos), and Grasshopper Sparrow (Ammodramus savannarum).
COASTAL SAGE SCRUB, CACTUS SCRUB
Natural Open Space Areas: 1, 4, 7, 8, 10, Sphere of Influence
Hillsides throughout the Puente Hills support stands of coastal sage scrub and cactus
scrub, and this includes the dry, exposed slopes of Diamond Bar. Dominant native
shrubs species in coastal sage scrub include California sagebrush (Artemisia californica),
California buckwheat (Eriogonum fasciculatum), black sage (Salvia mellifera), coyote brush
(Baccharis pilularis), laurel sumac (Malosma laurina), lemonade berry (Rhus integrifolia),
and blue elderberry (Sambucus nigra ssp. caerulea). Within the Study Area, cactus scrub
is dominated by a combination of coastal prickly-pear (Opuntia littoralis) and shrubs
characteristic of coastal sage scrub. The CDFW recognizes most of these scrub/cactus
3 http://vegetation.cnps.org/alliance/536
4 http://vegetation.cnps.org/alliance/499
11
alliances as Sensitive Natural Communities5 in their own right, and they often support
special-status plant and/or wildlife species, such as intermediate mariposa lily
(Calochortus weedii ssp. intermedius), Hubby’s phacelia (Phacelia hubbyi), Coastal
California Gnatcatcher (Polioptila californica californica), and Cactus Wren
(Campylorhynchus brunneicapillus).
CHAPARRAL
Natural Open Space Areas: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, Sphere of Influence
On Diamond Bar’s north- and east-facing slopes, coastal sage scrub is replaced by taller
and denser shrubs and trees with greater requirements for moisture and shade. The
mosaic consists of three main Natural Communities: chaparral, oak woodland, and
walnut woodland. The lowland form of chaparral found in the study area is dominated
by such species as laurel sumac (Malosma laurina), toyon (Heteromeles arbutifolia),
sugarbush (Rhus ovata), chaparral honeysuckle (Lonicera subspicata), and blue elderberry
(Sambucus nigra ssp. caerulea). Special-status species associated potentially found in
chaparral in Diamond Bar include Fish’s milkwort (Polygala cornuta var. fishiae) and the
San Bernardino Ringneck Snake (Diadophis punctatus modestus).
COAST LIVE OAK WOODLAND, SAVANNAH
Natural Open Space Areas: 1, 3, 4, 6, 7, 8, 10, 11, 12, Sphere of Influence
Coast Live Oak Woodland, several associations of which are recognized as Sensitive by
CDFW, is characterized by stands of coast live oak (Quercus agrifolia), and in some areas
Engelmann oak (Quercus engelmannii), often growing together with chaparral and
walnut woodland, on Diamond Bar’s north- and east-facing slopes, as well as in the
bottoms of some drainage courses. Oak savannah, characterized by scattered oaks
growing in grassland, occurs in limited pockets and may be associated with human
disturbance of oak woodlands. Coast live oaks are valuable to a variety of native
wildlife, and are frequently utilized by nesting owls and hawks. Special-status species
that may be found in oak woodlands in the Study Area include the Southern California
Shoulderband Snail (Helminthoglypta tudiculata), Trask’s Shoulderband Snail
(Helminthoglypta traskii), and Long-eared Owl (Asio otus).
CALIFORNIA WALNUT WOODLAND, SAVANNAH
Natural Open Space Areas: 1, 2, 4, 5, 6, 10, 12, Sphere of Influence
This Natural Community, recognized as Sensitive by CDFW, is characterized by stands
of southern California black walnut (Juglans californica) growing in association with
chaparral and coast live oak woodland on Diamond Bar’s north- and east-facing slopes.
Walnut savannah, characterized by scattered walnuts growing in grassland, occurs in
limited pockets and may be associated with human disturbance of walnut woodlands.
5 https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=153609
12
Special-status species that may be found in walnut woodlands and walnut savannah in
Diamond Bar include the species indicated previously for oak woodlands and
chaparral.
RIPARIAN SCRUB AND WOODLANDS
Natural Open Space Areas: 1, 4, 5, 6, 7, 8, 10, 12, 13, Diamond Bar Golf Course, Sphere
of Influence
Various forms of riparian scrub and woodland, nearly all of them recognized as
Sensitive by CDFW, grow along streambeds in Diamond Bar. The dominant vegetation
consists of willows, such as arroyo willow (Salix lasiolepis) and red willow (S. laevigata),
mulefat (Baccharis salicifolia), California sycamore (Platanus racemosa), coast live oak
(Quercus agrifolia), southern California black walnut (Juglans californica), and blue
elderberry (Sambucus nigra ssp. caerulea). Special-status species that may be found in
riparian woodlands in Diamond Bar include the rough hedge-nettle (Stachys rigida var.
rigida), Western Pond Turtle (Emys marmorata), Yellow-breasted Chat (Icteria virens), and
Yellow Warbler (Setophaga petechia).
HUMAN-ALTERED HABITATS
Developed areas, such as turfed/landscaped parks and the Diamond Bar Golf Course,
generally do not support Natural Communities, but these areas may nevertheless play
important ecological roles. For example, the golf course includes large number of
ornamental trees that comprise a non-native woodland that supports a wide variety of
resident and migratory native birds, presumably including nesting raptors, and the
man-made lake provides habitat for migratory and resident ducks and other waterfowl.
Natural Open Space Areas
Figures 3a–3d, starting on the next page, depict 13 areas of extensive (>25 acres)
native/naturalized habitat in Diamond Bar. Also depicted are Diamond Bar Golf
Course and Tonner Canyon/Significant Ecological Area 15, within the city’s Sphere of
Influence. The figures also show potential habitat connections/choke points for wildlife
movement between blocks of natural open space. Figures 3a–3d provide a basis for
generally characterizing the existing ecological conditions within Diamond Bar and its
Sphere of Influence, without accounting for such distinctions as the boundaries of
parklands or private lots.
13
14
15
16
Resource Protection
Recommendations
17
Resource Protection Recommendations
Table A, below, describes and characterizes the ecological characteristics of each
mapped natural open space area at a general level of detail appropriate for a General
Plan. Recommendations are made for the establishment of biological protection
overlays for sensitive habitat areas with high ecological values (e.g., native woodlands
and coastal sage scrub). Note that sensitive natural resources (e.g., special-status
species) and/or important ecological functions (e.g., movement of wildlife) could also
occur outside of the identified areas. More detailed, project-specific surveys would be
required to accurately and adequately describe the ecological resources found in any
open space area.
Table A. Resource Protection Recommendations
Area Acres Description/Main Communities/ Resource Protection Recommendations
1 926
Largest block of natural open space in Diamond Bar, including Pantera Park and northern
part of Tres Hermanos Ranch.
Grassland, Coastal Sage Scrub, Cactus Scrub, Chaparral, Oak Woodland, Walnut Woodland,
Riparian, Human-altered Habitats.
Establish biological protection overlay to conserve (a) large blocks of contiguous natural
habitat for Golden Eagles, Mountain Lions, and other species with large foraging areas, (b)
native scrub habitats with documented populations of California Gnatcatcher and Cactus
Wren, (c) wetland and riparian habitats, and (d) native woodlands; maintain and fortify
habitat connections and wildlife movement opportunities; minimize loss, fragmentation, and
degradation of Natural Communities.
2 64
Only large block of natural open space in Diamond Bar north of 60 Freeway.
Grassland, Coastal Sage Scrub, Chaparral, Coast Live Oak Woodland, Human-altered
Habitats.
Establish biological protection overlay to conserve native scrub habitats and native
woodlands; minimize loss, fragmentation, and degradation of Natural Communities; maintain
and fortify habitat connections and wildlife movement opportunities.
3 72
“Island” of natural open space between Charmingdale Road and Armitos Place.
Coast Live Oak Woodland, Coastal Sage Scrub, Grassland, Human-altered Habitats.
Establish biological protection overlay to conserve native scrub habitats and native
woodlands; minimize loss, fragmentation, and degradation of Natural Communities.
4 438
Includes Summitridge Park and Steep Canyon/Diamond Bar Creek.
Coastal Sage Scrub, Cactus Scrub, Oak Woodland, Riparian, Grassland, Human-altered
Habitats.
Establish biological protection overlay to conserve native scrub habitats with documented
populations of California Gnatcatcher and Cactus Wren, wetland and riparian habitats, and
native woodlands; minimize loss, fragmentation, and degradation of Natural Communities;
maintain and fortify habitat connections and wildlife movement opportunities.
18
Area Acres Description/Main Communities/ Resource Protection Recommendations
5 62
Includes Sycamore Canyon Park/Diamond Bar Creek.
Coastal Sage Scrub, Cactus Scrub, Oak Woodland, Riparian, Grassland, Human-altered
Habitats.
Establish biological protection overlay to conserve native scrub habitats, wetland and riparian
habitats, and native woodlands; minimize loss, fragmentation, and degradation of Natural
Communities; maintain and fortify habitat connections and wildlife movement opportunities.
6 196
Slopes east of City Hall.
Oak Woodland, Walnut Woodland, Oak/Walnut Savannah, Chaparral, Grassland, Coastal
Sage Scrub, Human-altered Habitats, Riparian.
Establish biological protection overlay to conserve native woodlands and savannah;
minimize loss, fragmentation, and degradation of Natural Communities; maintain and fortify
habitat connections and wildlife movement opportunities.
7 154
Includes Larkstone Park.
Coast Live Oak Woodland, Oak Savannah, Coastal Sage Scrub, Chaparral, Riparian,
Grassland, Human-altered Habitats.
Establish biological protection overlay to conserve native woodlands, wetland and riparian
habitats, and native scrub habitats; minimize loss, fragmentation, and degradation of Natural
Communities; maintain and fortify habitat connections and wildlife movement opportunities.
8 231
West of 57 Freeway, south of Pathfinder Road.
Oak Woodland, Oak/Walnut Savannah, Coastal Sage Scrub, Chaparral, Grassland, Human-
altered Habitats.
Establish biological protection overlay to conserve native woodlands and savannah, and
native scrub habitats; minimize loss, fragmentation, and degradation of Natural Communities;
maintain and fortify habitat connections and wildlife movement opportunities.
9 27
Southwestern corner.
Oak Woodland, Chaparral, Grassland.
Establish biological protection overlay to conserve native woodlands; minimize loss,
fragmentation, and degradation of Natural Communities.
10 712
Tonner Canyon tributaries.
Chaparral, Oak Woodland, Walnut Woodland, Oak/Walnut Savannah, Coastal Sage Scrub,
Riparian, Grassland, Human-altered Habitats.
Establish biological protection overlay to conserve native scrub habitats, wetland and riparian
habitats, and native woodlands and savannah; minimize loss, fragmentation, and degradation
of Natural Communities; maintain and fortify habitat connections and wildlife movement
opportunities.
11 39
Southwestern section of The Country; part of Significant Ecological Area 15.
Oak Woodland, Chaparral, Grassland.
Establish biological protection overlay to conserve native woodlands; minimize loss,
fragmentation, and degradation of Natural Communities.
19
Area Acres Description/Main Communities/ Resource Protection Recommendations
12 197
Slopes west of Ridge Line Road.
Oak Woodland, Walnut Woodland, Chaparral, Grassland, Coastal Sage Scrub, Human-
altered Habitats, Riparian.
Establish biological protection overlay to conserve native woodlands, wetland and riparian
habitats, and native scrub habitats; minimize loss, fragmentation, and degradation of Natural
Communities; maintain and fortify habitat connections and wildlife movement opportunities.
13 100
Northeastern part of The Country, adjacent to Tres Hermanos Ranch.
Grassland, Coastal Sage Scrub, Chaparral, Oak Woodland, Riparian, Human-altered
Habitats.
Establish biological protection overlay to conserve (a) large blocks of contiguous natural
habitat for Golden Eagles, Mountain Lions, and other species with large foraging areas, (b)
wetland and riparian habitats, and (c) native woodlands; maintain and fortify habitat
connections and wildlife movement opportunities; minimize loss, fragmentation, and
degradation of Natural Communities.
Diamond
Bar GC 174
Golf course that provides wildlife habitat.
Riparian, Human-altered Habitats (including man-made pond).
Conserve wetland and riparian habitats; maintain and fortify habitat connections and wildlife
movement opportunities.
Sphere of
Influence 3,513
Large and important area of natural open space south of Diamond Bar, including Pantera
Park and northern part of Tres Hermanos Ranch; heart of Significant Ecological Area 15.
Chaparral, Oak Woodland, Walnut Woodland, Oak/Walnut Savannah, Riparian, Grassland,
Coastal Sage Scrub.
Establish biological protection overlay to conserve (a) large blocks of contiguous natural
habitat for Golden Eagles, Mountain Lions, and other species with large foraging areas, (b)
wetland and riparian habitats, (c) native woodlands, and (d) native scrub habitats; minimize
loss, fragmentation, and degradation of Natural Communities.
Sensitive Resources
This biological resources report acknowledges federal, state, and local laws and
ordinances designed to protect and conserve sensitive resources, and identifies City
policies designed to help achieve this objective. For purposes of this report, a sensitive
resource refers to any of the following:
• A Natural Community recognized as having special-status by federal, State, and/or
local governments, and requiring a permit or agreement prior to its disturbance.
• A plant or animal species identified by federal or state governments as endangered,
threatened, rare, protected, sensitive, or a Species of Special Concern.
• A plant or animal that listed by a state or federal agency as a candidate species or
proposed for state or federal listing.
20
SENSITIVE NATURAL COMMUNITIES
The State of California identifies as “Sensitive” the following Natural Communities that
occur in Diamond Bar and its Sphere of Influence:
• Native Grasslands.
• Coastal Sage Scrub.
• Coast Live Oak Woodland (Q. agrifolia/Juglans californica; Q. agrifolia/Q.
berberidifolia/x acutidens; Q. agrifolia/Salvia leucophylla – Artemisia californica; Q.
agrifolia/Salix lasiolepis)6.
• California Walnut Woodland.
• Riparian Scrub and Woodland.
SPECIAL-STATUS SPECIES
In the following Table B, special-status plants and wildlife judged to have potential to
occur within Diamond Bar and its Sphere of Influence are identified and briefly
discussed. The potential for occurrence (low, moderate, high, or known to be present) is
based upon consideration of the species’ habitat requirements and the distribution of
previous verified or highly credible records.
Table B uses the following abbreviations:
• E Endangered (listed by State or Federal governments). “Take” of the
species or disturbance of occupied habitat are prohibited unless
specifically authorized.
• FP Fully Protected by the State of California. These species may not be taken or
possessed at any time, although take may be authorized for necessary
scientific research.
• T Threatened (listed by State or Federal governments). “Take” of the
species or disturbance of occupied habitat are prohibited unless
specifically authorized.
• SSC Species of Special Concern. The California Department of Fish and Wildlife
has designated certain vertebrate species as Species of Special Concern
because declining population levels, limited ranges, and/or continuing
threats have made them vulnerable to extinction. The goal of designating
species as Species of Special Concern is to halt or reverse their decline by
6 In addition to the four coast live oak associations designated as “Sensitive” by CDFW, oak woodlands
within the unincorporated Sphere of Influence are subject to the Los Angeles County Oak Woodlands
Conservation Management Plan pursuant to California Public Resources Code Section 21083 (requires a
county, when acting as a CEQA Lead Agency, to determine whether a proposed project “may result in a
conversion of oak woodlands that will have a significant effect on the environment”).
21
calling attention to their plight and addressing the issues of concern early
enough to secure their long term viability. Not all Species of Special
Concern have declined equally; some species may be just starting to
decline, while others may have already reached the point where they meet
the criteria for listing as a Threatened or Endangered species under the State
and/or Federal Endangered Species Acts.
• CNPS California Native Plant Society. Table B includes plant species
assigned the following ranks by CNPS:
o 1B.1, referring to species CNPS considers to be rare, threatened, or endangered in
California and elsewhere; seriously threatened in California (over 80% of occurrences
threatened / high degree and immediacy of threat).
o 1B.2, referring to species CNPS considers to be rare, threatened, or endangered in
California and elsewhere; moderately threatened in California (20-80% of
occurrences threatened / moderate degree and immediacy of threat).
o 1B.3, referring to species CNPS considers to be rare, threatened, or endangered in
California and elsewhere; not very threatened in California (less than 20% of
occurrences threatened / moderate degree and immediacy of threat).
o 2B.2, referring to species CNPS considers to be rare, threatened, or endangered in
California, but more common elsewhere; moderately threatened in California (20-
80% occurrences threatened / moderate degree and immediacy of threat).
o 4.1, referring to species of limited distribution or infrequent throughout a broader
area in California, whose status should be monitored regularly; moderately
threatened in California (>80% occurrences threatened / moderate degree and
immediacy of threat).
o 4.2, referring to species of limited distribution or infrequent throughout a broader
area in California, whose status should be monitored regularly; moderately
threatened in California (20-80% occurrences threatened / moderate degree and
immediacy of threat).
o 4.3, referring to species of limited distribution or infrequent throughout a broader
area in California, whose status should be monitored regularly; not very threatened in
California (less than 20% of occurrences threatened / low degree and immediacy of
threat or no current threats known).
• NatureServe Element Rankings. In some cases, species have not been granted
special status by state or federal agencies, but they may be recognized as
ecologically sensitive by the California Natural Diversity Database (CNDDB),
which uses a ranking methodology maintained by NatureServe. Species are given a
Global rank (G-rank) that applies to the taxon’s entire distribution, and a State rank
(S-rank) that applies to the taxon’s state distribution. Taxa with rankings of G1, G2,
G3, S1, S2, or S3 may be considered “sensitive” and potentially worthy of special
consideration in resource planning. NatureServe Element Rankings are identified in
Table B only for taxa that have no other federal or state special status.
22
NatureServe Ranks:
o G1, Critically Imperiled, referring to taxa at very high risk of extinction due to extreme
rarity ( often 5 or fewer populations), very steep declines, or other factors.
o G2, Imperiled, referring to taxa at high risk of extinction due to very restricted range, very
few populations (often 20 or fewer), steep declines, or other factors.
o G3, Vulnerable, referring to taxa at moderate risk of extinction due to a restricted range,
relatively few populations (often 80 or fewer), recent and widespread declines, or other
factors.
o S1, Critically Imperiled, referring to taxa critically imperiled in the state because of extreme
rarity (often 5 or fewer populations) or because of factor(s) such as very steep declines
making it especially vulnerable to extirpation from the state.
o S2, Imperiled, referring to taxa imperiled in the state because of rarity due to very restricted
range, very few populations (often 20 or fewer), steep declines, or other factors making it
very vulnerable to extirpation from the state.
o S3, Vulnerable, referring to taxa vulnerable in the state due to a restricted range, relatively
few populations (often 80 or fewer), recent and widespread declines, or other factors
making it vulnerable to extirpation from the state.
Table B. Special-Status Species
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Plants
Astragalus
brauntonii
Braunton’s
Milk-Vetch E — 1B.1
Associated with
calcareous soils.
Unrecorded in the
Puente Hills, but
populations to the
northwest (San
Gabriel Mts.) and
southeast (Chino
Hills, Santa Ana
Mts.).
Moderate potential to
occur in calcareous
substrate, if present.
Detectable only after fire
or other disturbance.
Brodiaea filifolia
Thread-
leaved
Brodiaea
— — 1B.1
Associated with clay
soils. Unrecorded in
the Puente Hills, but
populations to the
north (San Gabriel
Mts.) and southeast
(Santiago Hills).
Low potential to occur in
vernal pools, grasslands, or
openings in coastal sage
scrub.
Calochortus
catalinae
Catalina
Mariposa
Lily
— — 4.2
Widespread in
region, occurring in
clay soils.
Occurs in grasslands or
openings in coastal scrub
or chaparral.
Calochortus
clavatus
var. gracilis
Slender
Mariposa
Lily
— — 1B.2
Unrecorded in the
Puente Hills; popu-
lations to the north-
west (San Gabriel
Mts.).
Low potential to occur in
openings in coastal scrub
or chaparral.
23
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Calochortus
plummerae
Plummer’s
Mariposa
Lily
— — 4.2
Several recent
records of C. weedii
intermedius from
hills south of
Diamond Bar, within
the City’s Sphere of
Influence, may be C.
plummerae hybrids.
Potentially present. Occurs
in openings in coastal sage
scrub or chaparral.
Calochortus weedii
var. intermedius
Intermediate
Mariposa
Lily
— — 1B.2
Several recent
records from hills
south of Diamond
Bar, within the City’s
Sphere of Influence,
identified as C.
weedii intermedius,
but with potential for
hybridization with C.
plummerae.
Occurs in openings in
coastal sage scrub and
chaparral.
Convolvulus
simulans
Small-
flowered
Morning-
glory
— — 4.2
Scattered records
from the region,
including an old
record from 1 mile
east of Brea.
Moderate potential to
occur in grasslands or
openings in coastal sage
scrub. Found in moist
areas.
Dudleya
multicaulis
Many-
stemmed
Dudleya
— — 1B.2
Recorded close to
Diamond Bar, in
west Pomona.
Moderate potential to
occur in openings in
coastal sage scrub or
chaparral.
Horkelia cuneata
ssp. puberula
Mesa
Horkelia — — 1B.1
Unrecorded in the
Puente Hills;
scattered records
across the region.
Low to moderate potential
to occur in sandy openings
in chaparral and oak
woodland.
Juglans
californica
Southern
California
Black
Walnut
— — 4.2
Widespread in
region, including
Diamond Bar and its
Sphere of Influence.
Walnut and oak/walnut
woodlands occur
throughout Diamond Bar
and surrounding hills.
Lepidium
virginicum var.
robinsonii
Robinson’s
Peppergrass — — 4.3
Numerous historical
records from the
county’s interior
foothills, including
the western Puente
Hills; a few recent
records in and near
Diamond Bar.
Occurs in openings in
coastal sage scrub and
chaparral.
Microseris
douglasii ssp.
platycarpha
Small-
flowered
Microseris
— — 4.2
Recorded in
Diamond Bar, south
of Diamond Ranch
High School.
Occurs in grasslands.
Phacelia hubbyi Hubby’s
Phacelia — — 4.2
Several recent
records from
Pomona, Whittier,
and the Santa Ana
Mountain foothills.
High potential to occur in
openings in chaparral or
coastal scrub, such as
along edges of roads and
trails.
24
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Piperia cooperi Cooper’s
Rein-Orchid — — 4.2
Unrecorded in the
Puente Hills;
historical records
from as close as
Claremont and the
Santa Ana River
Canyon.
Low potential to occur in
oak/walnut woodlands,
chaparral, or coastal sage
scrub.
Polygala cornuta
var. fishiae
Fish’s
Milkwort — — 4.3
Recorded in Chino
Hills State Park and
San Gabriel Mts.
Moderate to high potential
to occur in oak/walnut
woodlands or chaparral.
Pseudognaphalium
leucocephalum
White
Rabbit-
tobacco
— — 2B.2
Unrecorded in the
Puente Hills; few
recent records from
surrounding areas.
Low potential to occur in
any sandy wash habitat
that may exist in the study
area.
Quercus
engelmannii
Engelmann
Oak — — 4.2
Recorded in the
Chino/Puente Hills,
La Habra and Yorba
Linda USGS quads.
Moderate potential to
occur in oak/walnut
woodlands.
Senecio aphanactis California
Groundsel — — 2B.2
Historical records
from San Dimas; few
recent records from
surrounding areas.
Moderate potential to
occur in chaparral,
oak/walnut woodlands, or
coastal sage scrub.
Symphyotrichum
defoliatum
San
Bernardino
Aster
— — 1B.2
Historical records
from southeastern
Los Angeles County.
Presumed extirpated.
Very low potential to occur
in moist areas, meadows.
Invertebrates
Bombas crotchii Crotch’s
Bumblebee — S1S2 —
Historical and recent
records scattered
around southern
California.
High potential to occur in
various habitats.
Helminthoglypta
tudiculata
Southern
California
Shoulder-
band Snail
— S1S2 —
Numerous records
from coastal slope of
southern California.
High potential to occur in
various habitats.
Helminthoglypta
traskii traskii
Trasks’s
Shoulder-
band Snail
— G1G2
S1 —
Numerous records
from coastal slope of
southern California.
High potential to occur in
various habitats.
Amphibians
Taricha torosa Coast Range
Newt — SSC —
Not known from
Chino Hills. Nearest
records in San
Gabriel Mts.
Low potential to occur in
and around permanent
water.
Spea hammondii Western
Spadefoot — SSC —
Widespread in region
but limited to
expansive natural
open space areas.
Moderate to high potential
to occur in extensive
grasslands and adjacent
communities with
temporary rain-pools for
breeding.
25
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Reptiles
Emys marmorata Western
Pond Turtle — SSC —
Found in expansive
natural areas, in and
around permanent
water that lacks non-
native turtles or
exotic predators.
Large population known
from Brea Creek; probably
occurs elsewhere in the
study area. Occurs in
creeks and ponds; lays
eggs in nearby uplands.
Phrynosoma
blainvillii
Coast
Horned
Lizard
— SSC —
Found in expansive
natural areas with
sandy openings and
native harvester ants.
High potential to occur in
areas of extensive
chaparral, coastal sage
scrub, and grassland.
Aspidoscelis tigris
stejnegeri
Coastal
Whiptail — SSC —
Widespread in the
region, in various
habitats.
Occurs in chaparral and
coastal sage scrub.
Anniella stebbinsi
So.
California
Legless
Lizard
— SSC —
Local in a variety of
habitats with sandy
soil or deep leaf-
litter.
Moderate potential in
chaparral and
chaparral/oak habitats.
Lampropeltis
zonata pulchra
San Diego
Mountain
Kingsnake
— SSC —
Widespread in the
region, in various
habitats.
Moderate potential to
occur in chaparral, coastal
sage scrub, oak
woodlands, and along
streams.
Arizona elegans
occidentalis
California
Glossy Snake — SSC —
Widespread, but
uncommon, in
habitats with soil
loose enough for
easy burrowing.
Moderate potential to
occur in areas that have
extensive patches of loose
soil.
Salvadora
hexalepis
virgultea
Coast Patch-
nosed Snake — SSC —
Widespread in the
region, in brushy and
rocky habitats.
Moderate potential to
occur in chaparral, coastal
sage scrub, oak
woodlands, and along
streams.
Thamnophis
hammondii
Two-striped
Garter Snake — SSC —
Widespread in the
region, in and
around perennial
water.
Moderate potential to
occur near perennial
water.
Crotalus ruber
Red
Diamond
Rattlesnake
— SSC — Widespread in the
region.
Occurs in cactus scrub,
coastal sage scrub, and
chaparral.
Birds
Geococcyx
californianus
Greater
Roadrunner — — —
Widespread in
expansive natural
areas with shrub
cover. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Resident in coastal sage
scrub and chaparral
habitats.
26
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Aquila
chrysaetos Golden Eagle — FP —
Formerly widespread
in many habitats, but
now limited to
expansive natural
areas. Nests on cliffs
and in tall trees away
from settlements.
Regularly observed
foraging in northeastern
part of study area. Pair
appears to be resident in
the Chino Hills/Diamond
Bar area; nesting status
unknown. Additional birds
may occur during
migration/winter.
Circus hudsonius Northern
Harrier — SSC —
Nests on the ground
in expansive open
space areas; more
widespread during
migration and winter.
Winters in open grassland
habitats. Moderate
potential to nest in the
northeastern and southern
parts of study area.
Elanus leucurus White-tailed
Kite — FP —
Nests in trees within
expansive open
space areas; more
widespread during
migration and winter.
Forages in
rangelands and
marshy areas.
One or more observed
near Diamond Ranch High
School on unspecified date
(Sage Environmental
Group 2012). High
potential to occur in
migration and winter,
especially in northeastern
and southern parts of study
area. Moderate potential to
nest in the northeastern or
southeastern parts of the
study area.
Buteo regalis Ferruginous
Hawk — — —
Winters in expansive
rangelands and
agricultural areas in
the region. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Moderate to high potential
to occur in migration and
winter, in northeastern and
southern parts of study
area. Does not nest in the
region.
Athene cunicularia Burrowing
Owl — SSC —
Nesting population
west of the deserts
nearly extirpated.
Winters rarely and
locally, usually in
expansive open
space areas.
Likely extirpated as nesting
species in Diamond Bar
area. Moderate potential to
occur in migration and
winter, especially in
northeastern and southern
parts of study area.
Asio otus Long-eared
Owl — SSC —
Resident in oak
woodlands, typically
>1 km from urban
areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Low to moderate potential
to occur in woodlands in
southeastern part of study
area.
Asio flammeus Short-eared
Owl — SSC —
Winters in expansive
open areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
Low potential to occur in
migration and winter, in
northeastern and southern
parts of study area. Does
not nest in the region.
27
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Falco mexicanus Prairie
Falcon — — —
Winters in expansive
rangelands and
agricultural areas in
the region. Nests on
remote cliffs.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
Low to moderate potential
to occur in migration and
winter, in northeastern and
southern parts of study
area. Unlikely to nest due
to lack of remote cliffs.
Empidonax traillii Willow
Flycatcher E E —
Does not nest in the
local area.
Uncommon during
migration.
No potential for nesting.
Species occurs in the study
area regularly during
migration periods.
Lanius
ludovicianus
Loggerhead
Shrike — SSC —
Nests rarely in the
region, in expansive
open space areas;
more widespread in
migration and winter.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
High potential to occur in
migration and winter,
especially in northeastern
and southern parts of study
area. Low to moderate
potential to nest in the
study area.
Vireo bellii bellii Least Bell’s
Vireo E E —
Nests uncommonly
in riparian scrub and
woodlands, often in
mulefat (Baccharis
salicifolia) or willow
(Salix spp.).
Moderate potential to nest
in riparian habitats,
especially in Tonner
Canyon.
Eremophila
alpestris Horned Lark — — —
Nests and winters in
expansive rangelands
and agricultural areas
in the region.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
Low potential to occur in
the northeastern and
southern parts of study
area.
Campylorhynchus
brunneicapillus
Cactus
Wren,
coastal
populations
— SSC —
Rare and declining
resident of cactus
scrub habitat.
Resident in well-developed
cactus scrub, including
Summitridge Park, Pantera
Park, Steep Canyon, and
hills south of Diamond
Ranch High School.
Polioptila
californica
californica
Coastal
California
Gnatcatcher
T SSC —
Uncommon resident
in coastal sage scrub
habitat, favoring
shallow slopes and
elevations below
1,500 feet.
Resident in coastal sage
scrub and cactus scrub,
including Summitridge
Park, Pantera Park, Steep
Canyon, and hills south of
Diamond Ranch High
School.
Sialia currucoides Mountain
Bluebird — — —
Winters in expansive
open areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
High potential to occur, at
least during some winters,
in northeastern and
southern parts of study
area. Does not nest in the
region.
Icteria virens
Yellow-
breasted
Chat
— SSC —
Nests uncommonly
in riparian scrub and
woodlands.
High potential to nest in
riparian habitats, especially
in Tonner Canyon.
28
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Setophaga
petechia
Yellow
Warbler — SSC — Nests in riparian
woodlands.
High potential to nest in
riparian habitats, especially
in Tonner Canyon.
Pooecetes
gramineus
Vesper
Sparrow — — —
Winters in expansive
open areas. Sensitive
species in Los
Angeles County
(Allen et al. 2009).
High potential to occur in
northeastern and southern
parts of study area. Does
not nest in the region.
Ammodramus
savannarum
Grasshopper
Sparrow — SSC —
Nests in expansive
grasslands and
rangelands.
High potential to nest in
open grassland and
rangeland habitat. Several
eBird records from the
Diamond Bar area in the
1990s; lack of recent
records probably reflects
lack of survey effort.
Sturnella neglecta Western
Meadowlark — — —
Nests rarely in the
region, in expansive
open space areas;
widespread in
migration and winter.
Sensitive species in
Los Angeles County
(Allen et al. 2009).
Occurs in open areas
throughout the study area;
moderate potential to nest
in the northeastern or
southern parts of study
area.
Agelaius tricolor Tricolored
Blackbird — SSC —
Nests in wetlands
adjacent to
expansive grasslands
and rangelands
required for foraging.
Winters in
rangelands and
parks.
Low potential to nest in the
study area. Moderate
potential to forage in open
grassland and rangeland
habitat during the nesting
season. Recorded in winter
at parks in the study area.
Mammals
Antrozous
pallidus Pallid Bat None SSC —
Widespread in
chaparral and similar
habitats, foraging on
the ground and in
vegetation. Roosts in
rock crevices and
under tree bark.
Maternal roosts
active between
March and August.
High potential; chaparral
and scrub on the site are
potentially suitable for
foraging and oaks provide
potential roosting sites
under exfoliating bark and
in cavities.
Eumops perotis
californicus
Western
Mastiff Bat None SSC —
Roosts in cliff
crevices and in
buildings.
Low potential; the species
may fly over the site
occasionally while
foraging, but suitable cliff
roosting habitat probably
absent.
Lasiurus blossevillii Western
Red Bat None SSC —
Roosts in foliage of
many types of tree;
feeds over a wide
variety of habitats.
Moderate potential to roost
in oak woodlands or
landscape trees; high
potential to forage over
undeveloped areas.
29
Latin name
Common
name Fed. State CNPS
Local and/or
Regional Status
Discussion
Lasiurus xanthinus Western
Yellow Bat None SSC —
Roosts primarily or
entirely in palms;
often forages over
water.
Moderate potential to roost
in palm trees and to forage
over water features.
Chaetodipus fallax
fallax
NW San
Diego Pocket
Mouse
None SSC —
Scrub habitats with
sandy or gravelly
soils.
High potential to occur in
cactus scrub and coastal
sage scrub habitats with
sutiable soils.
Neotoma lepida
intermedia
San Diego
Desert
Woodrat
None SSC —
Widespread in scrub
habitats, especially
those with cactus.
High potential to occur in
cactus-containing scrub.
Lepus californicus
bennettii
San Diego
Black-tailed
Jackrabbit
None SSC —
Occurs in various
open habitats,
usually in expansive
open space areas.
Low potential to occur in
the northeastern and
southern parts of the study
area.
Taxidea taxus American
Badger None SSC
Occurs in various
habitats, usually in
expansive open
space areas.
Moderate to high potential
to occur in the
northeastern and southern
parts of the study area.
EFFECTS OF DEVELOPMENT ON BIOLOGICAL RESOURCES
The capacity for a given natural open space area to maintain its ecological integrity (e.g.,
its resistance to invasion by exotic species, capacity to support special-status species)
depends upon such considerations as (a) size, with larger natural areas generally
possessing greater ecological value than do smaller ones; (b) plant communities
represented, with relatively undisturbed native communities generally being more
valuable than disturbed non-native communities; and (c) proximity to adjacent open
spaces, with areas linked to other natural areas generally possessing greater ecological
value compared with areas of similar size that are functionally isolated from other
natural areas.
A small, functionally isolated area that provides habitat for a rare plant or wildlife
species may have some ecological value, but conservation of such areas may prove to be
practically infeasible due to habitat degradation that often occurs near development
edges. Ecologically damaging “edge effects” include repeated clearing of habitat for fuel
modification leading to replacement of native plants with disturbance-adapted exotic
weeds; invasion of natural habitat by exotic ants facilitated by artificial irrigation near
homes; predation of birds, reptiles, and mammals by outdoor cats; and changes in
wildlife patterns associated with exterior lighting. To avoid perpetuating damaging
patterns of development that result in ever-smaller blocks of functionally isolated
habitat, the Open Space and Conservation Element must contain land-use policies that
encourage the preservation, restoration, and appropriate management of larger blocks
of well-connected habitat.
Readers seeking detailed information on these topics, with relevant citations from the
scientific literature, should refer to Appendix A.
30
Edge/Fragmentation Effects on Wildlife Movement
Constricting the movement of wildlife and plant seeds increases the risk of local
extinctions. Habitat fragmentation consequently threatens the viability of native plant
and wildlife populations in preserved areas. Large areas of habitat, or narrower
linkages of habitat between large areas, provide movement opportunities for wildlife.
Movement serves to facilitate the geographic distribution of genetic material, thus
maintaining a level of variability in the gene pool of an animal population. Influxes of
animals from nearby larger populations contribute to the genetic diversity of a local
population, helping to ensure the population’s ability to adapt to changing
environmental conditions. This is mainly accomplished through the dispersal of
juveniles from their natal territories, but may also involve movements in response to
drought or other adverse environmental conditions, or in response to wildfires or other
catastrophic events. Many plant species that depend on relatively sedentary insects for
pollination also benefit from habitat linkages that allow for genetic exchange and
dispersal. Likewise, plant seeds and propagules can be transported via the feces, fur, or
feathers of birds or mammals. Fragmentation effects are not limited to the physical
severing of movement routes, such as through the construction of a road or housing
development, but can include “edge effects” reviewed and described above. For
example, increases in night lighting and noise can disrupt the movement patterns of
species not well-adapted to such effects.
WILDLIFE MOVEMENT ISSUES IN THE PUENTE-CHINO HILLS
The Puente-Chino Hills ecosystem encompasses portions of four counties, and the open
space network in this area is sometimes referred to as the “Puente-Chino Hills Wildlife
Corridor.” Preserving land in the corridor has been a cooperative endeavor with other
public agencies and many nonprofit organizations. An important analysis by the
Conservation Biology Institute (2005), Maintaining Ecological Connectivity Across the
“Missing Middle” of the Puente-Chino Hills Wildlife Corridor, describes the situation as
follows (page v):
The Puente-Chino Hills Wildlife Corridor is a peninsula of mostly undeveloped hills jutting
about 42 km (26 miles) from the Santa Ana Mountains into the heart of the densely
urbanized Los Angeles Basin. Intense public interest in conserving open space here has
created a series of reserves and parks along most of the corridor’s length, but significant
gaps in protection remain. These natural habitat areas support a surprising diversity of
native wildlife, from mountain lions and mule deer to walnut groves, roadrunners, and
horned lizards. But maintaining this diversity of life requires maintaining functional
connections along the entire length of the corridor, so that wildlife can move between
reserves—from one end of the hills to the other.
Already the corridor is fragmented by development and crossed by numerous busy roads,
which create hazards and in some cases barriers to wildlife movement. Proposed
developments threaten to further degrade or even sever the movement corridor, especially
within its so-called “Missing Middle.” This mid-section of the corridor system, stretching
from Tonner Canyon on the east to Harbor Boulevard on the west, includes several large
properties proposed for new housing, roads, golf courses, and reservoirs. Such
31
developments would reduce habitat area and the capacity to support area-dependent
species and, if poorly designed, could block wildlife movement through the corridor.
The above-quoted report considered numerous studies of wildlife movement conducted
in the Puente-Chino Hills, and other relevant literature on wildlife movement corridors,
and recommended “conservation and management actions to prevent further loss of
ecological connectivity and retain native species.” The “Missing Middle” analysis
identified the following wildlife movement issues specifically relevant to Diamond Bar
and its Sphere of Influence:
• Tonner Canyon Bridge represents the only viable location for deer, mountain lions,
bobcats, and other species to pass under the 57 Freeway.
• Any development in middle and especially lower Tonner Canyon could have
severe impacts on corridor function, especially if wildlife access to Tonner Canyon
Bridge is reduced. Any development that blocks access through the bridge area
would make the 57 Freeway a complete barrier to many species and would likely
lead to wildlife extirpations in segments farther west.
• An earlier plan to build a road running the length of Tonner Canyon would have
split the Chino-Tonner “subcore” in two, potentially rendering dysfunctional the
critical Tonner Bridge wildlife undercrossing for wide-ranging species such as the
mountain lion, bobcat, and mule deer.
• At least the middle and lower portions of Tonner Canyon should be conserved,
including a prohibition on any new road or other development that would fragment
this critical habitat block.
• No project should be approved that would increase traffic under the Tonner Bridge
or add any new impediments (structures, lights, noise, etc.) to the vicinity of the
bridge.
• Restore riparian vegetation along Tonner Creek, where degraded by oil
development activities.
• Fencing may be warranted along the 57 Freeway if monitoring suggests road
mortality is high.
Planning of any future development in Diamond Bar and its Sphere of Influence should
take exceptional care to preserve and enhance the viability of the Puente-Chino Hills
Wildlife Corridor.
Regional Planning in the Puente-Chino Hills Wildlife Corridor
Two agencies are specifically involved in planning development and taking
conservation actions in and around the Puente-Chino Hills Wildlife Corridor.
The Wildlife Corridor Conservation Authority (WCCA) was established to provide for
the proper planning, conservation, environmental protection, and maintenance of lands
32
within and around the Puente-Chino Hills Wildlife Corridor. Its goal is to assure that
sufficient continuity of habitat can be preserved to maintain a functioning wildlife
corridor made up of about 40,000 acres of land located between the Santa Ana
Mountains and Whittier Hills. The governing board of the WCCA consists of
representatives from the cities of Brea, Whittier, Diamond Bar, La Habra Heights, the
Santa Monica Mountains Conservancy, California Department of Parks and Recreation,
California Department of Fish and Game (ex officio member), Los Angeles County, and
two public members. A large Advisory Committee meets separately to provide input.
The WCCA consistently provides comments on development proposals and other
projects to support environmentally sensitive activities in the Puente-Chino Hills
Wildlife Corridor.
The Puente Hills Habitat Preservation Authority (PHHPA) is a public agency, Joint
Powers Authority, with a Board of Directors consisting of the City of Whittier, County
of Los Angeles, Sanitation Districts of Los Angeles County, and the Hacienda Heights
Improvement Association. The jurisdiction of the PHHPA extends from the intersection
of the 605 and 60 Freeways east to Harbor Boulevard. The PHHPA is dedicated to the
acquisition, restoration, and management of open space in the Puente Hills for
preservation of the land in perpetuity, with the primary purpose to protect the
biological diversity.
NATURAL RESOURCE CONSERVATION POLICIES
The City of Diamond Bar has developed a suite of conservation measures, presented in
this section, designed to allow for the planned growth of the City while protecting and
conserving irreplaceable natural communities and their component species. These
policies align the local approach to development with the conservation regulations and
policies set forth by the federal government (e.g., the federal Endangered Species Act);
the State of California (e.g., the California Environmental Quality Act and the California
Fish and Game Code); and local entities (e.g., the Los Angeles County Oak Woodlands
Conservation Plan; see Los Angeles County Oak Woodlands Habitat Conservation
Strategic Alliance 2011, Los Angeles County Dept. of Regional Planning 2014).
Prioritizing the identification and protection of sensitive natural resources facilitates
efforts of City planners and elected officials to ensure that Diamond Bar remains a
beautiful and desirable place to live.
Goals and Policies of the Open Space and Conservation Element
• RC-I-1. Obtain and designate Open Space land through acquisition techniques,
such as:
a. Design new development projects emphasizing preservation of sensitive natural
resources, natural geological features, and wildlife corridors and habitat
linkages, through site design approaches that include greenbelts, landscaping
with locally native, drought-adapted plants, and dedication of a portion of the
site as natural open space.
33
b. Allow for acquisition of open space lands during the entitlement process
through the transfer of densities among land uses of like designation.
c. Identify ecologically sensitive/unique habitats, including habitat linkages and
choke-points, within the City of Diamond Bar and prioritize their
acquisition/preservation/restoration as a preferred form of mitigation for future
development.
d. Collaborate with land trusts, joint-power authorities, and other conservation
groups to acquire and restore open space land through, but not limited to,
conservation easements and conservation plans.
• RC-I-2. As future parks are developed or open space is acquired/dedicated:
a. Preserve sensitive natural communities to maintain ecological integrity and
provide for passive recreation opportunities, such as hiking and bird-watching.
b. Site trails to avoid removal or fragmentation of sensitive natural communities
and to minimize erosion.
c. Prohibit the application of use of outdoor pesticide bait stations, or similar,
within 500 feet of any natural open space.
• RC-G-4. Provide recreational and cultural opportunities to the public in a
manner that maintains, restores, protects, and preserves sensitive natural
resources in the City of Diamond Bar and its Sphere of Influence.
• RC-I-12. Support and cooperate with efforts to identify and preserve
environmentally sensitive and strategically located canyon areas and hillsides
that serve as wildlife corridors and habitat linkages/choke points within
Diamond Bar and its Sphere of Influence, including components of the Puente-
Chino Hills Wildlife Corridor, Tres Hermanos Ranch, Tonner Canyon, and
Significant Ecological Area (SEA) 15, to provide regional connectivity, and to
sustain the ecological function of natural habitats and biological resources.
a. Establish appropriate resource protection overlays for ecologically sensitive
areas (see page 18 of this report).
b. Require adequate biological resources surveys as part of planning of
development proposed in any area with potential for special-status species
or sensitive natural communities to occur.
c. Discourage development in areas with identified sensitive natural resources,
natural geological features, and wildlife corridors and habitat linkages/choke
points, in order to preserve them in a natural state, unaltered by grading, fill,
or diversion activities (except as may be desirable for purposes of habitat
restoration and/or facilitation of wildlife movement).
34
d. Preserve and restore native woodlands in perpetuity, with a goal of no net
loss of existing woodlands, through compliance with Chapter 22.38 of the
Diamond Bar – Tree Preservation and Protection.
e. In the unincorporated Sphere of Influence, require that impacts to native oak
trees be treated in a manner consistent with Section 22.46.2100 of the
County of Los Angeles Code of Ordinances, except that in-lieu fees shall not
be accepted as mitigation for removal of regulated oaks. If replacement of
oaks is determined to be necessary, this should be conducted under a City-
administered Tree Mitigation Program developed in consultation with a
qualified biologist and Certified Arborist or Certified Urban Forester to
establish a to ensure that replacement trees are planted on public property
in areas that (a) shall not impact any existing sensitive habitat areas; (b) are
appropriate for the long-term survival of native trees planted as mitigation;
and (c) shall be maintained and preserved by the city, in perpetuity, as
natural open space for the mitigation trees and any associated understory
species deemed appropriate to provide valuable woodland habitat.
f. For development proposed adjacent to natural open space, require use of
highly fire-resistant building materials and methods, which minimize fuel
modification treatments.
g. In areas adjacent to natural open space, require use of highly fire-resistant
building materials and architecture for public safety and to minimize
requirements for damaging fuel modification treatments.
h. Fuel modification adjacent to natural open spaces should employ
exclusively native plant species approved for use in fuel modification zones,
which provide important habitat for native wildlife and minimize ongoing
irrigation and disturbance of the exterior slopes, reducing the potential for
exotic ants and weeds to become established on the site and then spread to
nearby natural open space areas.
• RC-I-28.5. Conserve natural open spaces, biological resources, and vegetation,
recognizing their roles in the reduction and mitigation of air pollution impacts,
and the promotion of carbon sequestration.
LITERATURE CITED
Allen, L. W., and Los Angeles County Sensitive Bird Species Working Group. 2009. Los Angeles County’s
Sensitive Bird Species. Western Tanager 75(3):E1–E11.
City of Diamond Bar and Diamond Bar Historical Society. 2014. Images of America, Diamond Bar. Arcadia
Publishing, Charleston, South Carolina.
Conservation Biology Institute. 2005. Maintaining Ecological Connectivity Across the “Missing Middle” of
the Puente-Chino Hills Wildlife Corridor. Encinitas, CA.
https://d2k78bk4kdhbpr.cloudfront.net/media/reports/files/pcmissingmiddle.pdf
35
Dyett & Bhatia. 2017. City of Diamond Bar General Plan Update, Existing Conditions Report – Volume III.
Redline draft dated February 21, 2017, prepared for City of Diamond Bar.
Los Angeles County, Dept. of Regional Planning. 2014. Los Angeles County Oak Woodlands Conservation
Management Plan Guide. Report dated March 18, 2014.
http://planning.lacounty.gov/assets/upl/project/oakwoodlands_conservation-management-plan-
guide.pdf
Los Angeles County Oak Woodlands Habitat Conservation Strategic Alliance. 2011. Los Angeles County
Oak Woodlands Conservation Management Plan. Report dated May 2011.
http://file.lacounty.gov/SDSInter/bos/bc/162273_official_20110620_oak-woodlands.pdf
Lower San Gabriel River Watershed Group. 2015. Lower San Gabriel River Watershed Management
Program.
https://www.waterboards.ca.gov/rwqcb4/waterissues/programs/stormwater/municipal/watershedman
agement/sangabriel/lowersangabriel/LowerSGRiverFinalWMP.pdf
Neal, S. 2011. Brea History – the Brea Creek. Brea Historical Society Brea Museum & Heritage Center.
Sage Environmental Group. 2012. Affordable Housing Land Use and Zoning Designation Project, Biological
Survey Report. Report dated August 2012 prepared for City of Diamond Bar.
Sheng, J. and J. P. Wilson. 2008. The Green Visions Plan for 21st Century Southern California. 16.
Watershed Assets Assessment Report. University of Southern California GIS Research Laboratory
and Center for Sustainable Cities, Los Angeles, CA.
U.S. Army Corps of Engineers. 1991. Los Angeles County Drainage Area Review, Final Feasibility Study,
Interim Report and Environmental Impact Statement. Vandergast, A. G., A. J. Bohonak, D. B.
Weissman, and R. N. Fisher. 2006. Understanding the genetic effects of recent habitat fragmentation
in the context of evolutionary history: Phylogeography and landscape genetics of a southern
California endemic Jerusalem cricket (Orthoptera: Stenopelmatidae: Stenopelmatus). Molecular
Ecology 16:977–92.
H AMILTON B IOLOGICAL
February 20, 2019
Greg Gubman
Director of Community Development
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
SUBJECT: APPENDIX A TO OPEN SPACE AND CONSERVATION ELEMENT
DIAMOND BAR GENERAL PLAN UPDATE
METHODS AND TECHNICAL INFORMATION
Dear Mr. Gubman,
A consortium of Diamond Bar residents retained Hamilton Biological, Inc., (hereafter
“Hamilton Biological”) to prepare an Open Space and Conservation Element for the
City of Diamond Bar (hereafter the “City”) to consider incorporating into a forthcoming
update to its General Plan. This letter describes the methods used to prepare the pro-
posed Open Space and Conservation Element, and provides technical biological infor-
mation that underpins the report’s findings and recommendations.
METHODS
Literature Review
As an initial step, Robert Hamilton, President of Hamilton Biological, reviewed the Bio-
logical Resources section of Dyett & Bhatia (2017) and a partial rough draft of an Open
Space and Conservation Element prepared by Cooper Ecological Monitoring, Inc. Mr.
Hamilton also reviewed a biological report prepared by Sage Environmental Group
(2012) for an Affordable Housing Land Use and Zoning Designation Project proposed
on a site covering 78 acres in the northeastern part of the City, near Diamond Ranch
High School.
Special-status species with potential to occur in Diamond Bar and adjacent areas were
identified through review of the California Natural Diversity Database (2018a, 2018b,
2018c) and searches of eBird (https://ebird.org); California Native Plant Society’s
Online Inventory of Rare and Endangered Plants (www.rareplants.cnps.org); review of
the list of Los Angeles County’s Sensitive Bird Species (Allen et al. 2009;
https://losangelesaudubon.org/images/stories/pdf/WesternTanager_pdfs/Vol.75/vo
l75no03jan-feb2009.pdf); the Consortium of California Herbaria web page
(www.ucjeps.berkeley.edu/consortium); Sage Environmental Group (2012); Dyett &
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 2 of 9
Bhatia (2017); and the online Flora of the Skyline Trail, Puente Hills, Los Angeles County
(Muns, B., 1982; http://tchester.org/plants/muns/pr/skyline_trail.html).
Mapping and Field Surveys
Robert A. Hamilton mapped the natural open space areas throughout the City and its
Sphere of Influence using Google Earth Pro. Potential habitat linkages and/or choke-
points for wildlife movement were identified by examination of aerial imagery. Mr.
Hamilton conducted reconnaissance field surveys on January 4 and 8, and February 4
and 8, 2019, to field-check the mapping and to observe the existing conditions through-
out most of Diamond Bar. Mr. Hamilton has visited the portion of Tonner Canyon that
lies within the City’s Sphere of Influence on numerous occasions in recent years, and
thus has viewed the natural resources found in that part of the study area, as well.
Classification of Natural Communities
Since the mid-1990s, CDFW and its partners, including the California Native Plant
Society (CNPS), have been working on classifying vegetation types using standards
embodied in the Survey of California Vegetation, which comply with the National
Vegetation Classification Standard (NVCS; http://usnvc.org/explore-classification/). The
NVCS is a hierarchical classification, with the most granular level being the Association.
Associations are grouped into Alliances, Alliances into Groups, and upward, as follows:
Formation Class > Formation Subclass > Formation > Division > Macrogroup > Group
> Alliance > Association. For purposes of this Open Space and Conservation Element,
Natural Communities are generally classified at the more generalized levels (e.g.,
Group), but for environmental review of specific projects in Diamond Bar, Natural
Communities should be classified and mapped at the more detailed Alliance or
Association level.
The method recommended by CDFW for classifying Natural Communities and
conducting CEQA review reads as follows:
• Identify all Natural Communities within the project footprint using the best means
possible, for example, keying them out in the Manual of California Vegetation,
Second Edition (Sawyer et al. 2009) or in classification or mapping reports from the
region, available on VegCAMP’s Reports and Maps page.
• Refer to the current standard list of Natural Communities to determine if any of
these types are ranked Sensitive (S1-S3 rank); if so, see CEQA Guidelines checklist
at IVb.
• Other considerations when assessing potential impacts to Sensitive Natural
Communities from a project include:
1. Compliance with state and federal wetland and riparian policies and codes,
as certain Natural Communities are restricted to wetlands or riparian set-
tings.
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 3 of 9
2. Compliance with the Native Plant Protection Act and the state and federal
Endangered Species Acts, as some Natural Communities either support rare
species or are defined by the dominance or presence of such species.
3. Compliance with CEQA Guidelines Section 15065(a), which mandates
completion of an EIR if a project would threaten to eliminate a plant com-
munity.
4. Compliance with local regional plans, regulations, or ordinances that call
for consideration of impacts to Natural Communities.
5. Vegetation types that are not on the state’s sensitive list but that may be con-
sidered rare or unique to the region under CEQA Guidelines Section
15125(c).
• If a Natural Community in the project area has not previously been described, it
may be a rare type. In this case, please contact VegCAMP (Todd Keeler-Wolf or
Diana Hickson) about documenting the Natural Community.
• If there are Sensitive Natural Communities on your project site and you need
guidance, contact the appropriate regional staff person through the local CDFW
Regional Office to discuss potential project impacts; these staff have local
knowledge and context.
Identifying Sensitive Natural Communities
The California Department of Fish and Wildlife (CDFW), at its VegCAMP page, pro-
vides guidance on appropriate methods for “Addressing Sensitive Natural Communi-
ties in Environmental Review”:
https://www.wildlife.ca.gov/Data/VegCAMP/Natural-Communities#sensitive%20natural%20communities
The State’s guidance consists of the following steps:
• Identify all Natural Communities within the project footprint using the best means
possible, for example, keying them out in the Manual of California, Second Edition
(Sawyer et al. 2009) or in classification or mapping reports from the region,
available on VegCAMP’s Reports and Maps page.
• Refer to the current standard list of Natural Communities to determine if any of
these types are ranked Sensitive (S1-S3 rank); if so, see CEQA Guidelines checklist
at IVb.
• Other considerations when assessing potential impacts to Sensitive Natural
Communities from a project include:
o Compliance with state and federal wetland and riparian policies and codes,
as certain Natural Communities are restricted to wetlands or riparian set-
tings.
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 4 of 9
o Compliance with the Native Plant Protection Act and the state and federal
Endangered Species Acts, as some Natural Communities either support rare
species or are defined by the dominance or presence of such species.
o Compliance with CEQA Guidelines Section 15065(a), which mandates
completion of an EIR if a project would threaten to eliminate a plant com-
munity.
o Compliance with local regional plans, regulations, or ordinances that call
for consideration of impacts to Natural Communities.
• Vegetation types that are not on the State’s sensitive list but that may be considered
rare or unique to the region under CEQA Guidelines Section 15125(c).
• If a Natural Community in the project area has not previously been described, it
may be a rare type. In this case, please contact VegCAMP (Todd Keeler-Wolf or
Diana Hickson) about documenting the Natural Community.
• If there are Sensitive Natural Communities on your project site and you need guid-
ance, contact the appropriate regional staff person through the local CDFW Re-
gional Office to discuss potential project impacts; these staff have local knowledge
and context.
• The Department’s document, Protocols for Surveying and Evaluating Impacts to
Special Status Native Plant Populations and Natural Communities (PDF) provides
information on reporting.
The City of Diamond Bar should employ the above-described methods to ensure the
thoroughness and adequacy of CEQA documentation completed within the City and its
Sphere of Influence.
Important Considerations for Oak Woodlands
As of January 2005, California Public Resources Code Section 21083.4 (2004 Senate Bill
1334) requires that when a county is determining the applicability of CEQA to a project,
it must determine whether that project “may result in a conversion of oak woodlands
that will have a significant effect on the environment.” If such effects (either individual
impacts or cumulative) are identified, the law requires that they be mitigated. Accepta-
ble mitigation measures include, but are not limited to, conservation of other oak wood-
lands through the use of conservation easements and planting replacement trees, which
must be maintained for seven years.
Diamond Bar’s Sphere of Influence, south of the city limits, lies within unincorporated
Los Angeles County, and thus the City’s General Plan should acknowledge that the
County of Los Angeles Department of Regional Planning issued in 2014 an Oak Wood-
lands Conservation Management Plan Guide1, with three important objectives: (1) pri-
1 http://planning.lacounty.gov/assets/upl/project/oakwoodlands_conservation-management-plan-guide.pdf
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 5 of 9
oritize the preservation of oak woodlands; (2) promote conservation by integrating oak
woodlands into the development process in a sustainable manner; and (3) effectively
mitigate the loss of oak woodlands.
ADVERSE EFFECTS OF DEVELOPMENT ON PRESERVED HABITAT AREAS
One purpose of a General Plan is to guide future development so as to minimize ad-
verse effects upon sensitive Natural Communities and declining native plant and wild-
life populations, to the extent feasible. Beyond the outright removal of natural areas,
which obviously impacts natural resources, development projects inevitably degrade
and fragment habitats along the urban/wildland interface. Such secondary, or indirect,
impacts have been subject to intensive study in recent years, to (a) understand and
characterize them, and (b) develop strategies for minimizing and mitigating them. The
following discussions, including citations from the scientific literature, provide the basis
for the General Plan’s land-use policies concerning edge and fragmentation effects.
Urbanization typically includes residential, commercial, industrial, and road-related
development. At the perimeter of the built environment is an area known as the ur-
ban/wildland interface, or “development edge.” Edges are places where natural com-
munities interface, vegetation or ecological conditions within natural communities in-
teract (Noss 1983), or patches with differing qualities abut one another (Ries and Sisk
2004). “Edge effects” are spillover effects from the adjacent human-modified matrix
that cause physical gradients in light, moisture, noise, etc. (Camargo and Kapos 1995;
Murcia 1995, Sisk et al. 1997) and/or changes in biotic factors such as predator commu-
nities, density of human-adapted species, and food availability (Soulé et al. 1988;
Matlack 1994; Murcia 1995; Ries and Sisk 2004). Loss, degradation, and fragmentation of
habitat due to urbanization are the most pervasive threats to biodiversity in southern
California (Soulé 1991). Edge-related impacts may include:
• Introduction/expansion of invasive exotic vegetation carried in from vehicles, peo-
ple, animals or spread from backyards or fuel modification zones adjacent to
wildlands.
• Increased frequency and/or severity of fire as compared to natural fire cycles or in-
tensities.
• Companion animals (pets) that often act as predators of, and/or competitors with,
native wildlife.
• Creation and use of trails that often significantly degrade intact ecosystems through
such changes as increases in soil disturbance, vegetation damage, and noise.
• Introduction of or increased use by exotic animals which compete with or prey on
native animals.
• Pesticide exposure can be linked to cancer, endocrine disruption, reproductive ef-
fects, neurotoxicity, kidney and liver damage, birth defects, and developmental
changes in a wide range of species, from insects to top predators.
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 6 of 9
• Influence on earth systems and ecosystem processes, such as solar radiation, soil
richness and erosion, wind damage, hydrologic cycle, and water pollution that can
affect the natural environment.
Any of these impacts, individually or in combination, can result in the effective loss or
degradation of habitats used for foraging, breeding or resting, with concomitant effects
on population demographic rates of sensitive species.
The coastal slope of southern California is among the most highly fragmented and ur-
banized regions in North America (Atwood 1993). Urbanization has already claimed
more than 90 percent of the region’s coastal sage scrub habitat, 99 percent of the coastal
prairie, and 95 percent of the vernal pools (McCaull 1994; Mattoni & Longcore 1997;
Bauder & McMillan 1998). A review of studies completed by Harrison and Bruna (1999)
identified a general pattern of reduction of biological diversity in fragmented habitats
compared with more intact ones, particularly with regard to habitat specialists. While
physical effects associated with edges were predominant among species impacts, they
found evidence for indirect effects including altered ecological interactions. Fletcher et
al. (2007) found that distance from edge had a stronger effect on species than did habitat
patch size, but they acknowledged the difficulty in separating those effects empirically.
Many southern California plant and animal species are known to be sensitive to frag-
mentation and edge effects; that is, their abundance declines with fragment size and
proximity to an edge (Wilcove 1985; Soulé et al. 1992; Bolger et al. 1997a,b; Suarez et al.
1998; Burke and Nol 2000).
Wildlife populations are typically changed in proximity to edges, either by changes in
their demographic rates (survival and fecundity), or through behavioral avoidance of or
attraction to the edge (Sisk et al. 1997; Ries and Sisk 2004). For example, coastal sage
scrub areas within 250 meters of urban edges consistently contain significantly less bare
ground and more coarse vegetative litter than do more “intermediate” or “interior” are-
as, presumably due increased human activity/disturbance of the vegetation structure
near edges (Kristan et al. 2003). Increases in vegetative litter often facilitate growth of
non-native plants (particularly grasses), resulting in a positive feedback loop likely to
enhance plant invasion success (Wolkovich et al. 2009). In another coastal southern Cali-
fornia example, the abundance of native bird species sensitive to disturbance is typical-
ly depressed within 200 to 500 meters (650 to 1640 feet) of an urban edge, and the abun-
dance of disturbance-tolerant species is elevated up to 1000 meters (3280 feet) from an
urban edge, depending on the species (Bolger et al. 1997a).
Habitat fragmentation is usually defined as a landscape scale process involving habitat
loss and breaking apart of habitats (Fahrig 2003). Habitat fragmentation is among the
most important of all threats to global biodiversity; edge effects (particularly the diverse
physical and biotic alterations associated with the artificial boundaries of fragments) are
dominant drivers of change in many fragmented landscapes (Laurance and Bierregaard
1997; Laurance et al. 2007).
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 7 of 9
Fragmentation decreases the connectivity of the landscape while increasing both edge
and remnant habitats. Urban and agricultural development often fragments wildland
ecosystems and creates sharp edges between the natural and human-altered habitats.
Edge effects for many species indirectly reduce available habitat use or utility in sur-
rounding remaining areas; these species experience fine-scale functional habitat losses
(e.g., see Bolger et al. 2000; Kristan et al. 2003; Drolet et al. 2016). Losses of coastal sage
scrub in southern California have increased isolation of the remaining habitat fragments
(O’Leary 1990) and led to calls to preserve and restore landscape connectivity to permit
long-term persistence of native species with low vagility (e.g., Vandergast et al. 2006).
Fragmentation has a greater relative negative impact on specialist species (e.g., coastal
populations of the Cactus Wren, Campylorhynchus brunneicapillus) that have strict vege-
tation structure and area habitat requirements (Soulé et al. 1992). Specialist species have
an increased risk of extirpation in isolated habitat remnants because the specialized
vegetative structures and/or interspecific relationships on which they depend are more
vulnerable to disruption in these areas (Vaughan 2010). In studies of the coastal sage
scrub and chaparral systems of coastal southern California, fragment area and age (time
since isolation) were the most important landscape predictors of the distribution and
abundance of native plants (Soulé et al. 1993), scrub-breeding birds (Soulé et al. 1988;
Crooks et al. 2001), native rodents (Bolger et al. 1997b), and invertebrates (Suarez et al.
1998; Bolger et al. 2000).
Edge effects that emanate from the human-dominated matrix can increase the extinction
probability of isolated populations (Murcia 1995; Woodroffe and Ginsberg 1998). In
studies of coastal sage scrub urban fragments, exotic cover and distance to the urban
edge were the strongest local predictors of native and exotic carnivore distribution and
abundance (Crooks 2002). These two variables were correlated, with more exotic cover
and less native shrub cover closer to the urban edge (Crooks 2002).
The increased presence of human-tolerant “mesopredators” in southern California rep-
resents an edge effect of development; they occur within the developed matrix and are
thus more abundant along the edges of habitat fragments, and they are effective preda-
tors on birds, bird nests, and other vertebrates in coastal sage scrub and chaparral sys-
tems and elsewhere (Crooks and Soulé 1999). The mammalian carnivores more typically
detected in coastal southern California habitat fragments are resource generalists that
likely benefit from the supplemental food resources (e.g., garden fruits and vegetables,
garbage, direct feeding by humans) associated with residential developments. As a re-
sult, the overall mesopredator abundance, of such species as raccoons (Procyon lotor),
opossums (Didelphis virginiana), and domestic cats (Felis catus), increases at sites with
more exotic plant cover and closer to the urban edge (Crooks 2002). Although some
carnivores within coastal sage scrub fragments seem tolerant of disturbance, many
fragments have (either actually or effectively) already lost an entire suite of predator
species, including mountain lion, bobcats (Lynx rufus), spotted skunks (Spilogale gracilis),
long-tailed weasels (Mustela frenata), and badgers (Taxidea taxus) (Crooks 2002). Most
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 8 of 9
“interior” sites within such fragments are still relatively near (within 250 meters of) ur-
ban edges (Crooks 2002).
Fragmentation generally increases the amount of edge per unit land area, and species
that are adversely affected by edges can experience reduced effective area of suitable
habitat (Temple and Cary 1988), which can lead to increased probability of extirpa-
tion/extinction in fragmented landscapes (Woodroffe and Ginsberg 1998). For example,
diversity of native bees (Hung et al. 2015) and native rodents (Bolger et al. 1997b) is
lower, and decomposition and nutrient cycling are significantly reduced (Treseder and
McGuire 2009), within fragmented coastal sage scrub ecosystems as compared to larger
core reserves. Similarly, habitat fragmentation and alterations of sage scrub habitats
likely have reduced both the genetic connectivity and diversity of coastal-slope popula-
tions of the Cactus Wren in southern California (Barr et al. 2015). Both Bell’s Sparrows
(Artemisiospiza belli) and California Thrashers (Toxostoma redivivum) show strong evi-
dence of direct, negative behavioral responses to edges in coastal sage scrub; that is,
they are edge-averse (Kristan et al. 2003), and California Thrashers and California Quail
(Callipepla californica) were found to be more vulnerable to extirpation with smaller
fragment size of the habitat patch (Bolger et al. 1991), demonstrating that both behav-
ioral and demographic parameters can be involved. Other species in coastal sage scrub
ecosystems, particularly the Cactus Wren and likely the California Gnatcatcher and San
Diego Pocket Mouse (Chaetodipus fallax), are likely vulnerable to fragmentation, but for
these species the mechanism is likely to be associated only with extirpation vulnerabil-
ity from habitat degradation and isolation rather than aversion to the habitat edge (Kris-
tan et al. 2003). Bolger (et al. 1997b) found that San Diego coastal sage scrub and chapar-
ral canyon fragments under 60 acres that had been isolated for at least 30 years support
very few populations of native rodents, and they suggested that fragments larger than
200 acres in size are needed to sustain native rodent species populations.
The penetration of exotic species into natural areas can reduce the effective size of a re-
serve in proportion to the distance they penetrate within the reserve: Argentine Ants
serve as an in-depth example of edge effects and fragmentation. Spatial patterns of Ar-
gentine Ant abundance in scrub communities of southern California indicate that they
are likely invading native habitats from adjacent developed areas, as most areas sam-
pled greater than 200 to 250 meters from an urban edge contained relatively few or no
Argentine Ants (Bolger 2007, Mitrovich et al. 2010). The extent of Argentine Ant inva-
sions in natural environments is determined in part by inputs of urban and agricultural
water run off (Holway and Suarez 2006). Native ant species were more abundant away
from edges and in areas with predominately native vegetation. Post-fragmentation edge
effects likely reduce the ability of fragments to retain native ant species; fragments had
fewer native ant species than similar-sized plots within large unfragmented areas, and
fragments with Argentine ant-free refugia had more native ant species than those with-
out refugia (Suarez et al. 1998). They displace nearly all surface-foraging native ant spe-
cies (Holway and Suarez 2006) and strongly affect all native ant communities within
about 150 to 200 meters from fragment edges (Suarez et al. 1998; Holway 2005; Fisher et
al. 2002; Bolger 2007; Mitrovich et al. 2010). Argentine Ants are widespread in frag-
Appendix A to Open Space and Conservation Element, Diamond Bar General Plan Hamilton Biological, Inc.
February 20, 2019 Page 9 of 9
mented coastal scrub habitats in southern California, and much of the remaining poten-
tial habitat for Blainville’s Horned Lizards (Phrynosoma blainvillii) is effectively unsuita-
ble due to the penetration of Argentine ants and the subsequent displacement of the na-
tive ant species that Coastal Horned Lizards need as prey (Fisher et al. 2002). Invasion
of Argentine Ants into coastal sage scrub has also shown a strong negative effect on the
abundance of the gray shrew (Notiosorex crawfordi) (Laakkonen et al. 2001).
An evaluation by the U.S. Environmental Protection Agency (2008) concluded that each
of ten of the most common active ingredients in rodenticides “poses significant risks to
non-target wildlife when applied as grain-based bait products. The risks to wildlife are
from primary exposure (direct consumption of rodenticide bait) for all compounds and
secondary exposure (consumption of prey by predators or scavengers with rodenticide
stored in body tissues) from the anticoagulants.” Thus, the common practice of setting
out bait within or near natural areas can be expected to have adverse effects upon a
range of native wildlife species.
Finally, in the Santa Monica Mountains of Los Angeles County, populations of such na-
tive amphibians as the California newt (Taricha torosa) and California treefrog
(Pseudacris cadaverina) were found to decline with urbanization of as little as 8% of a
given watershed (Riley et al. 2005). Such faunal community changes appear to be relat-
ed to changes in physical stream habitat, such as fewer pool and more run habitats and
increased water depth and flow. These changes are associated with increased erosion
and with invasion by damaging exotic species, such as the red swamp crayfish (Procam-
barus clarkii).
CONCLUSION
I appreciate the opportunity to provide this technical informtion in support of the Open
Space and Conservation Element for the Diamond Bar General Plan. If you have ques-
tions, please call me at (562) 477-2181 or send e-mail to robb@hamiltonbiological.com.
Sincerely,
Robert A. Hamilton
President, Hamilton Biological, Inc.
316 Monrovia Avenue
Long Beach, CA 90803
562-477-2181
robb@hamiltonbiological.com
Attached: Literature Cited
Literature Cited, Appendix A to Open Space and Conservation Element, DBGP Hamilton Biological, Inc.
February 19, 2019 Literature Cited
LITERATURE CITED
Allen, L. W., and Los Angeles County Sensitive Bird Species Working Group. 2009. Los Angeles County’s
Sensitive Bird Species. Western Tanager 75(3):E1–E11.
Barr, K. R., B. E. Kus, K. L. Preston, S. Howell, E. Perkins, and A. G. Vandergast. 2015. Habitat fragmentation
in coastal southern California disrupts genetic connectivity in the Cactus Wren (Campylorhynchus brun-
neicapillus). Molecular Ecology 24:2349–2363.
Bauder, E. T., and S. McMillan. 1998. Current distribution and historical extent of vernal pools in southern
California and northern Baja California, Mexico. Pp. 56–70 in Ecology, Conservation and Management
of Vernal Pool Ecosystems (C. W. Witham, E. T. Bauder, D. Belk, W. R. Ferren Jr., and R. Ornduffm, edi-
tors). California Native Plant Society, Sacramento.
Bolger, D. T. 2007. Spatial and temporal variation in the Argentine ant edge effect: implications for the
mechanism of edge limitation. Biological Conservation 136:295–305.
Bolger, D. T., A. C. Alberts, and M. E. Soulé. 1991. Occurrence patterns of bird species in habitat fragments:
sampling, extinction, and nested species subsets. The American Naturalist 137(2):155–166.
Bolger, D. T., T. A. Scott, and J. T. Rotenberry. 1997a. Breeding bird abundance in an urbanizing landscape
in coastal southern California. Conservation Biology 11(2):406–421.
Bolger, D. T., A. C. Alberts, R. M. Sauvajot, P. Potenza, C. McCalvin, D. Tran, S. Mazzoni, and M. E. Soulé.
1997b. Response of rodents to habitat fragmentation in coastal southern California. Ecological Applica-
tions 7(2):552–563.
Bolger, D. T., A. V. Suarez, K. R. Crooks, S. A. Morrison, and T. J. Case. 2000. Arthropods in urban habitat
fragments in southern California: area, age, and edge effects. Ecological Applications 10(4):1230-1248.
Burke, D. M., and E. Nol. 2000. Landscape and fragment size effects on reproductive success of forest-
breeding birds in Ontario. Ecological Applications 10(6):1749–1761.
California Natural Diversity Database. 2018a. Special Vascular Plants, Bryophytes, and Lichens List. Current
list of vegetative taxa considered to be rare, threatened, endangered, or otherwise “sensitive” by the
State of California. List dated November 2018.
California Natural Diversity Database. 2018b. Special Animals List. Current list of wildlife taxa considered to
be rare, threatened, endangered, or otherwise “sensitive” by the State of California. List dated November
2018.
California Natural Diversity Data Base. 2018c. Rarefind data accessed online on July 6, 2018, for the U.S.
Geologic Survey’s Yorba Linda, San Dimas, Ontario, and Prado Dam 7.5’ topographic quadrangles.
Camargo, J. L. C., and V. Kapos. 1995. Complex edge effects on soil moisture and microclimate in central
Amazonian forest. Journal of Tropical Ecology 11(2):205–221.
Conservation Biology Institute. 2005. Maintaining Ecological Connectivity Across the “Missing Middle” of
the Puente-Chino Hills Wildlife Corridor. Encinitas, CA.
https://d2k78bk4kdhbpr.cloudfront.net/media/reports/files/pc_missing_middle.pdf
Crooks, K. R. 2002. Relative sensitivities of mammalian carnivores to habitat fragmentation. Conservation
Biology 16(2):488–502.
Literature Cited, Appendix A to Open Space and Conservation Element, DBGP Hamilton Biological, Inc.
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Crooks, K. R., and M. E. Soulé. 1999. Mesopredator release and avian extinctions in a fragmented system.
Nature 400:563–566.
Crooks, K. R., A. V. Suarez, D. T. Bolger, and M. E. Soulé. 2001. Extinction and colonization of birds on
habitat islands. Conservation Biology 15(1):159–172.
Drolet, A., C. Dussault, and S. D. Côté. 2016. Simulated drilling noise affects the space use of a large terres-
trial mammal. Wildlife Biology 22(6):284–293.
Dyett & Bhatia. 2017. City of Diamond Bar General Plan Update, Existing Conditions Report – Volume III.
Redline draft dated February 21, 2017, prepared for City of Diamond Bar.
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October 31, 2019
Grace Lee
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
Re: Comments on Draft Environmental Impact Report and Diamond Bar General Plan
Ms. Lee,
Thank you very much for the opportunity to provide comments on Diamond Bar’s Draft
Environmental Impact Report (DEIR) and General Plan (DBGP). The process has been very
open, and I have greatly appreciated the transparency in which the plan and report
development has been conducted. The General Plan Advisory Committee provided some
reasonable solutions where the City should focus its development. I appreciate that the
General Plan and EIR have primarily focused on the redevelopment of infill or existing
commercial areas, rather than rezoning out existing open spaces for development. Also you
have given some thought and consideration on how the City of Diamond Bar is part of a large r
environment (Sphere of Influence) that needs to be thoughtfu lly considered for wildlife
movement and for the greater ecosystem of the Puente and Chino Hills in general.
The comments I provide below are similar to three of the priorities identified during the City’s
outreach and input in the GPAC Meetings: Environment, Recreation and Traffic.
Environment
Although I understand that most development will be targeted in areas of in -fill or
reconstruction of existing commercial areas, we should consider that in areas where ther e is
potential for sensitive or protected resources, that we are specific to what would be required to
ensure that the City is in compliance and ensures their protection or conservation. I am
professional environmental specialist, so these edits are requirements that I am familiar with
and are reasonable to implement, and minimize potential for inadvertent discoveries resulting
in schedule delays in subsequent permitting and mitigation or agency actions from
environmental non-compliance impacts. I would like to suggest a few minor changes to the
language—my comments are in red and strikeout.
RC-P-9 on page 3.3-45
Require, as part of the environmental review process, prior to approval of discretionary
development projects involving parcels within, adjacent to, or surrounding a significant
biological resource area, a biotic resources evaluation of the site by a qualified biologist .,
Focused plant surveys shall be conducted at the appropriate time of year, and local
reference populations checked to ensure detectability of the target species. requiring
that time-specific issues such as the seasonal cycle of plants Wildlife shall also be
evaluated by a qualified biologist through appropriate survey or trapping techniques
necessary to determine presence. and migration of wildlife are evaluated. Such
evaluation shall analyze the existing and potential natural resources of a given site
following at least one site visit as well as the potential for significant adverse impacts on
biological resources. The report and shall identify measures to avoid, minimize, or
mitigate any impacts to species that have been observed or have the potential of being
present on the site. that would degrade its healthy function . In approving any permit
based on the evaluation, the City shall require implementation of mitigation measures
supported by the evaluation, or work with the applicant to modify the project if mitigation
is determined not to be adequate to reduce the impacts to a non-significant level.
MM-BIO-1A on page 3.3-47
To the extent feasible the preconstruction surveys shall be completed when species are
in bloom, typically between May and June and reference populations checked. Two
species, the white rabbit-tobacco and San Bernardino aster, are perennial herbs that grow
up to three feet in height and can be identified by their dried stalks and leaves following
their blooming period.
The suggestion of adding language for checking reference populations will ensure accuracy of
detecting target sensitive plant species. This requirement is not overly burdensome, but more
of due diligence and ensuring that the species being surveyed for will even be detectable.
Many sensitive species have identified reference populations that can be easily checked prior to
conducting any field work—this should save time and effort on subsequent fieldwork as well.
MM-BIO-1B on page 3.3-47
At a minimum, the plan shall include a description of the existing conditions of the project
and receiver site(s), transplanting and/or seed collection/off-site seeding or installation
methods, an adaptive two-year monitoring program, any other necessary monitoring
procedures, plant spacing, and maintenance requirements. In the event, that the City of
DB determines that agreed success criteria are not met, additional remediation may be
required beyond the two-year maintenance/monitoring period to ensure mitigation
requirements are met.
If the mitigation measure conditions are not met in the established two -year timeframe, it
should be the developer’s obligation to meet those mitigation measure requirements. It has
been my experience that there needs to be assurance that the developer has met obligations.
In the two years of monitoring, there should be adaptive management of the site to ensure
success. This is common language that many land use agencies have added to their
requirements to put the onus on the developer to ensure the intent of the mitigation measure
is met. My concern for the City is if it is not clear to the developer on what the requirements
are, the City of Diamond Bar risks being the responsible party for the additional restoration
expense, or risk the establishment of exotic weed species that could exacerbate the potential
for wildfire.
MM-BIO-1D Environmental Awareness Program on page 3.3-48
The City shall implement an Environmental Awareness Training Program on its web site
intended to increase awareness to developers, residents and city workers of the sensitive
plants, wildlife and associated habitats that occur in the preserved open space areas. The
intention purpose of the program shall be to inform developers, city workers and
residents. The program shall address safety, environmental resource sensitivities and
impacts associated with the introduction of invasive plant species as a result of new
development. At a minimum, the Environmental Awareness Program shall include the
following components:
encourage Provide, on the City website, information about proactive conservation efforts
among for the residents and city to help conserve the habitats in the preserved open
space. The program shall address impacts associated with the introduction of invasive
plant species as a result of new development. At a minimum, the Environmental
Awareness Program shall include the following components:
I appreciate the approach that the City is taking to increase environmental awareness. My edits
were an attempt to include the developer in this outreach. The Environmental and Safety
Awareness Training should be developed that is tailored and specific to each project based on
resource or safety concerns. It should be the responsibility of the contractor or developer to
ensure that the workers have taken the awareness training and provide documentation if
requested by the City of Diamond Bar that the project proponent understands their role in
safety and compliance. Again, this is a reasonable requirement common on many construction
projects.
MM-BIO-1E on page 3.3-49
Preconstruction Surveys for Special-Status Wildlife: Within one (1) week prior to initiating
disturbance activities, clearance surveys for special-status animal species shall be
performed by a qualified biologist(s) within the boundaries of the future proj ect
disturbances. If any special-status animals are found on the site, a qualified biologist(s)
flag the area for avoidance and discuss possible seasonal avoidance measures with the
developer. If avoidance is not feasible, the Project Biologist, with a CDFG Scientific
Collection Permit shall relocate these species to suitable habitats within surrounding open
space areas that would remain undisturbed, unless the biologist determines that such
relocation cannot reasonably be accomplished at which point CDFG will be consulted
regarding whether relocation efforts should be terminated. Relocation methods (e.g.,
trap and release) and receiver sites shall be verified and approved by the CDFG prior to
relocating any animals.
It is important that as a first option in protection of resources, avoidance is the preferred
option. Therefore, this measure should include the steps to avoid or minimize impacts to
identified resources. If after all possible avoidance measures are used, then a qualified
biologists should consider relocation of the resource (ie. plant or animal). This suggested
language is common practice and is reasonable in consultation with a permitted or approved
biologist.
Recreation
As a father of two young girls, recreational opportunities and parks are very important to my
family. I am a member of the Board for our local AYSO Soccer Region as well as a coach and
referee, so I am familiar with the shortage of parks for practice and recreation. I also live on the
south side of Diamond Bar, so I also know that the lack of adequate park facilities on the
southern end of town. I was concerned when I read that the City determined that the impacts
to recreation were Significant and Unavoidable. You had identified a Core Community Overlay
as part of the DBGP Preferred Alternative. Understanding that the Los Angeles County Golf
Course is not currently a viable alternative, it was still identified in this EIR as an alternative
option. So, why did the City not consider the golf course in addressing the significant recreation
impacts associated with the low ratio of 2 acres per 1000 residents? I would encourage an
additional discussion regarding the necessary acreage needed to mitigate these impacts. As
part of the Core Community Overlay how much of that property could be reserved to meet the
requirement of the Quimby Act (5 acres per 1000 residents)?
Also, as a question regarding CEQA analysis. It is my understanding that the Golf Course, in
order to be used for other purposes, would need to be mitigated for that loss with another
comparable location as a golf course. If there are additional environmental impacts associated
with the Golf Course’s conversion in the Core Community Overlay option, those impacts would
need to be disclosed in this DEIR. Or alternatively another subsequent EIR would need to be
developed if in the future the Community Overlay option is viable. Is my assumption correct,
that the Golf Course property is only theoretical and any future development of that property
would be contingent on another CEQA analysis?
Traffic and other Project Alternatives
As a resident of Diamond Bar, I am well aware of the issues around the through traffic on
Diamond Bar Blvd, Grand Ave. and Golden Springs/Colima Road. I understand that the impacts
associated with traffic, although significant f or Level of Service and Vehicle Miles Traveled,
would be difficult to mitigate and therefore are determined to be unmitigatable. So, I
understood that the GPAC elected to not select, in their recommendations, to continue the
Diamond Bar Blvd and Grand Ave intersection as the Diamond Bar City Center due to the traffic
congestion. Although I agree with this approach, it does not seem reasonable that the existing
City Center is not analyzed as a feasible alternative in the EIR. The DEIR only analyzed the
existing City Center as infeasible as the No Project Alternative under the existing GP. However,
I think the existing City Center warrants an Alternatives Analysis under the proposed mitigation
measures and City land use policies. I suggest that the City analyze this alternative because the
City’s preferred alternative and Alternative 2 are contingent on the Golf Course being
developed. These alternatives, if contingent on the Golf Course, are incomplete in that the
impacts associated with an alternative county golf course were neither described nor analyzed
in this EIR—and would therefore require a subsequent EIR analysis. Therefore, it is not clear
that either of these two alternatives are feasible at this time.
Again, thank you for your consideration and the opportunity to provide comments on the DEIR
and DBGP. I look forward to additional correspondence from the City as the Final EIR becomes
available.
Sincerely,
Gary Busteed
20850 Gold Run Drive
Diamond Bar, CA 91765
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 2: Comments on the Draft EIR
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3 Responses to Comments
This chapter includes responses to comment s on environmental issues, in the same order as
presented in Chapter 2 : Comments on the Draft EIR . The responses are marked with the same
number-letter designator as the comment to which they respond.
Responses to written comments received during the public review period are summarized in the
matrix below. The reference number and text of the comments are presented alongside the response
for ease of reference. Where the same comment has been made more than once, a response may
direct the reader to another numbered comment and response.
Responses focus on comments that raise important environmental issues or pertain to the adequacy
of analysis in the Draft EIR or to other aspects pertinent to the potential effects of the Proposed
Project on the environment pursuant to CEQA. Comments that address policy issues, opinions or
other topics beyond the purview of the Draft EIR or CEQA are noted as such for the public record.
Where comments are on the merits of the Proposed Project rather than on the Draft EIR, these are
also noted in the responses. Where appropriate, the information and/or revisions suggested in the
comment letters have been incorporated into the Final EIR. Revisions are acknowledged where
necessary to clarify or amplify and are included in Chapter 4. Figure revisions required in response
to comments are noted in the matrix and the revised figures are included in Chapter 4.
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Chapter 3: Responses to Comments
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Table 3-1: Response to Comments Matrix
Comment ID Comment Response
Agencies
A1 COUNTY OF LOS ANGELES FIRE DEPARTMENT
A1-1 October 17, 2019
Grace Lee, Senior Planner
City of Diamond Bar
Planning Division
21810 Copley Drive
Diamond Bar, CA 91765
Dear Ms. Lee:
NOTICE OF AVAILABILITY OF DRAFT ENVIRONMENTAL
IMPACT REPORT, "DIAMOND BAR GENERAL PLAN," WILL
ESTABLISH THE CITY'S OVERALL APPROACH TO
DEVELOPMENT, PUBLIC SERVICES, AND OTHER ISSUES FOR
THE NEXT 20 YEARS, CITYWIDE - DIAMOND BAR, FFER (sic)
2019005639
Notice of Availability of Draft Environmental Impact Report
has been reviewed by the Planning Division, Land
Development Unit, Forestry Division, and Health Hazardous
Materials Division of the County of Los Angeles Fire
Department.
The following are their comments:
This comment is the salutation of the letter and introduces comments A1 -2
through A1-8. Responses to these comments are provided below.
A1-2 PLANNING DIVISION:
Under Section 7.0, Public Safety, Fire Service, of the Draft
EIR, the first sentence in paragraph one, needs to be
corrected to state that there are three fire stations serving
Comment acknowledged.
With regards to fire stations, Chapter 3.7 states: “The City is served by the
County of Los Angeles Fire Department, and unincorporated portions of the
Planning Area are served by the Los Angeles County Fire Department and CAL
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Table 3-1: Response to Comments Matrix
Comment ID Comment Response
the City of Diamond Bar and NOT three within the City
Limits.
For any questions regarding this response, please contact
Loretta Bagwell, Planning Analyst, at (323) 881-2404 or
Loretta.BagwelI@fire.lacounty.gov.
FIRE. The locations of the three fire stations that serve the Planning Area are
shown in Figure 3.7-4.” (page 3.7-16). Chapter 3.11 states: “The locations of
the three fire stations that serve the City are depicted on Figure 3.11-1, and
staffing and equipment at each station are shown in Table 3.11-1.” (page
3.11-2). Both chapters clearly state that there are three fire stations serving
the City of Diamond Bar and do not state that there are three fire stations
within City Limits.
A1-3 LAND DEVELOPMENT UNIT:
The Land Development Unit is reviewing the proposed
"Diamond Bar general plan 2040 and climate action plan"
Project for access and water system requirements.
The Land Development Unit comments are only
preliminary requirements. Specific fire and life safety
requirements will be addressed during the review for
building and fire plan check phases. There may be
additional requirements during this time.
The development of this project must comply with all
applicable code and ordinance requirements for
construction, access, water mains, fire flows, and fire
hydrants.
Development associated with the proposed Diamond Bar General Plan 2040
and Climate Action Plan would be subject to applicable code and ordinance
requirements for construction, access, water mains, fire flows, and fire
hydrants. The Regulatory Settings sections within Draft EIR chapters include
applicable code and ordinance requirements.
A1-4 ACCESS REQUIREMENTS:
1. The proposed development will require multiple
ingress/egress access for the circulation of traffic and
emergency response issues.
2. All on-site Fire Department vehicular access roads shall
be labeled as "Private Driveway and Fire Lane" on the
site plan along with the widths clearly depicted on the
plan. Labeling is necessary to assure the access
availability for Fire Department use. The designation
allows for appropriate signage prohibiting parking.
This comment lists access requirements that development associated with the
Proposed Project would be subject to. It does not address the adequacy of the
Draft EIR; therefore, no further response is required.
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Table 3-1: Response to Comments Matrix
Comment ID Comment Response
a. The Fire Apparatus Access Road shall be cross-
hatch on the site plan with the width clearly
noted on the plan.
3. Every building constructed shall be accessible to Fire
Department apparatus by way of access roadways with
an all-weather surface of not less than the prescribed
width. The roadway shall be extended to within 150
feet of all portions of the exterior walls when measured
by an unobstructed route around the exterior of the
building.
4. Fire Apparatus Access Roads must be installed and
maintained in a serviceable manner prior to and during
the time of construction.
5. The edge of the Fire Apparatus Access Road shall be
located a minimum of 5 feet from the building or any
projections there from.
6. The Fire Apparatus Access Roads and designated fire
lanes shall be measured from flow line to flow line.
7. The dimensions of the approved Fire Apparatus Access
Roads shall be maintained as originally approved by the
fire code official.
8. Provide a minimum unobstructed width of 28 feet,
exclusive of shoulders and an unobstructed vertical
clearance "clear to sky" Fire Department vehicular
access to within 150 feet of all portions of the exterior
walls of the first story of the building, as measured by
an approved route around the exterior of the building
when the height of the building above the lowest level
of the Fire Department vehicular access road is more
than 30 feet high or the building is more than three
stories. The access roadway shall be located a minimum
of 15 feet and a maximum of 30 feet from the building
and shall be positioned parallel to one entire side of the
building. The side of the building on which the aerial
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Table 3-1: Response to Comments Matrix
Comment ID Comment Response
Fire Apparatus Access Road is positioned shall be
approved by the fire code official.
9. If the Fire Apparatus Access Road is separated by island,
provide a minimum unobstructed width of 20 feet,
exclusive of shoulders and an unobstructed vertical
clearance "clear to sky" Fire Department vehicular
access to within 150 feet of all portions of the exterior
walls of the first story of the building as measured by an
approved route around the exterior of the building.
10. Dead-end Fire Apparatus Access Roads in excess of 150
feet in-length shall be provided with an approved Fire
Department turnaround. Include the dimensions of the
turnaround with the orientation of the turnaround shall
be properly placed in the direction of travel of the
access roadway.
11. Fire Department Access Roads shall be provided with a
32-foot centerline turning radius. Indicate the
centerline, inside, and outside turning radii for each
change in direction on the site plan.
12. Fire Apparatus Access Roads shall be designed and
maintained to support the imposed load of fire
apparatus weighing 75,000 lbs. and shall be surfaced so
as to provide all-weather driving capabilities. Fire
Apparatus Access Roads having a grade of 10 percent or
greater shall have a paved or concrete surface.
13. Provide approved signs or other approved notices or
markings that include the words "NO PARKING - FIRE
LANE." Signs shall have a minimum dimension of 12
inches wide by 18 inches high and have red letters on a
white reflective background. Signs shall be provided for
Fire Apparatus Access Roads, to clearly indicate the
entrance to such road, or prohibit the obstruction
thereof and at intervals, as required by the Fire
Inspector.
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Table 3-1: Response to Comments Matrix
Comment ID Comment Response
14. A minimum 5-foot wide approved firefighter access
walkway leading from the Fire Department Access Road
to all required openings in the building's exterior walls
shall be provided for firefighting and rescue purposes.
Clearly identify firefighter walkway access routes on the
site plan. Indicate the slope and walking surface
material. Clearly show the required width on the site
plan.
15. Fire Apparatus Access Roads shall not be obstructed in
any manner, including by the parking of vehicles, or the
use of traffic calming devices, including but not limited
to, speed bumps or speed humps. The minimum widths
and clearances established in Fire Code Section 503.2.1
shall be maintained at all times.
16. Traffic Calming Devices, including but not limited to,
speed bumps and speed humps, shall be prohibited
unless approved by the fire code official.
17. Security barriers, visual screen barriers, or other
obstructions shall not be installed on the roof of any
building in such a manner as to obstruct firefighter
access or egress in the event of fire or other
emergency. Parapets shall not exceed 48 inches from
the top of the parapet to the roof surface on more than
two sides. Clearly indicate the height of all parapets in a
section view.
18. Approved building address numbers, building numbers,
or approved building identification shall be provided
and maintained so as to be plainly visible and legible
from the street fronting the property. The numbers
shall contrast with their background, be Arabic
numerals or alphabet letters, and be a minimum of 4
inches high with a minimum stroke width of 0.5 inch.
19. Multiple residential and commercial buildings having
entrances to individual units not visible from the street
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Table 3-1: Response to Comments Matrix
Comment ID Comment Response
or road shall have unit numbers displayed in groups for
all units within each structure. Such numbers may be
grouped on the wall of the structure or mounted on a
post independent of the structure and shall be
positioned to be plainly visible from the street or road
as required by Fire Code 505.3 and in accordance with
Fire Code 505.
A1-5 WATER SYSTEM REQUIREMENTS:
1. All fire hydrants shall measure 6"x 4 'l x 2-1/2" brass or
bronze conforming to current AWWA standard 0503 or
approved equal and shall be installed in accordance
with the County of Los Angeles Fire Code.
2. The development may require fire flows up to 4,000
gallons per minute at 20 pounds per square inch
residual pressure for up to a four-hour duration. Final
fire flows will be based on the size of buildings, the
installation of an automatic fire sprinkler system, and
type(s) of construction used.
3. The fire hydrant spacing shall be every 300 feet for both
the public and the on-site hydrants. The fire hydrants
shall meet the following requirements:
a. No portion of lot frontage shall be more than
200 feet via vehicular access from a public fire
hydrant.
b. No portion of a building shall exceed 400 feet
via vehicular access from a properly spaced
public fire hydrant.
c. Additional hydrants will be required if hydrant
spacing exceeds specified distances.
4. All required public fire hydrants shall be installed and
tested prior to beginning construction.
5. All private on-site fire hydrants shall be installed,
tested, and approved prior to building occupancy.
This comment lists water system requirements that development associated
with the General Plan would be subject to. It does not address the adequacy
of the Draft EIR; therefore, no further response is required.
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a. Plans showing underground piping for private
on-site fire hydrants shall be submitted to the
Sprinkler Plan Check Unit for review and
approval prior to installation.
6. An approved automatic fire sprinkler system is required
for the proposed buildings within this development.
Submit design plans to the Fire Department Sprinkler
Plan Check Unit for review and approval prior to
installation.
A1-6 Additional Department requirements will be determined by
Fire Prevention Engineering during the Building Plan Check.
For any questions regarding the response, please contact
Inspector Claudia Soiza at (323) 890-4243 or
Claudia.soiza@fire.lacounty.aov.
Comment acknowledged. It does not address the adequacy of the Draft EIR;
therefore, no further response is required.
A1-7 FORESTRY DIVISION - OTHER ENVIRONMENTAL CONCERNS:
The statutory responsibilities of the County of Los Angeles
Fire Department's Forestry Division include erosion control,
watershed management, rare and endangered species,
vegetation, fuel modification for Very High Fire Hazard
Severity Zones, archeological and cultural resources, and the
County Oak Tree Ordinance. Potential impacts in these
areas should be addressed.
Under the Los Angeles County Oak tree Ordinance, a permit
is required to cut, destroy, remove, relocate, inflict damage
or encroach into the protected zone of any tree of the Oak
genus which is 25 inches or more in circumference (eight
inches in diameter), as measured 4 1/2 feet above mean
natural grade.
Impacts associated with soil erosion are discussed in Chapter 3.6: Geology,
Soils, and Seismicity, specifically under Impact 3.6-2. Given the
implementation of proposed General Plan policies aimed at preventing
erosion, this impact is determined to be less than significant.
Impacts associated with watershed management are discussed in Chapter 3.8:
Hydrology and Water Quality, specifically under Impacts 3.8-1, 3.8-2, and 3.8-
3. Given the implementation of proposed General Plan policies aimed at
preserving natural watersheds, these impacts are determined to be less than
significant.
Impacts associated with rare and endangered species and vegetation are
discussed in Chapter 3.3: Biological Resources. Given the implementation of
proposed General Plan policies aimed at protecting biological resources in the
Planning Area and extensive mitigation, these impacts are determined to be
less than significant with mitigation. In the event that a future project would
result in the loss of an oak woodland, development as sociated with the
proposed General Plan would be subject to Mitigation Measure MM-BIO-4,
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If Oak trees are known to exist in the proposed project area
further field studies should be conducted to determine the
presence of this species on the project site.
The County of Los Angeles Fire Department's Forestry
Division has no further comments regarding this project
For any questions regarding this response, please contact
Forestry Assistant, Joseph Brunet at (818) 890-5719.
which implements the mitigation requirements of the Los Angeles County Oak
Woodland Conservation Management Plan Guide within the Planning Area.
Impacts associated with development in Very High Fire Hazard Severity Zones
are discussed in Chapter 3.7: Hazards, Hazardous Materials, and Wildfire,
specifically under Impacts 3.7-8 through 3.7-11. Given the implementation of
Los Angeles County Fire Department Fuel Modification Plans within the
Sphere of Influence (SOI) and proposed General Plan policies aimed at
development proposed within High or Very High Fire Hazard Severity Zones,
these impacts are determined to be less than significant.
Impacts associated with archaeological and cultural resources are discussed in
Chapter 3.4: Cultural, Historic, and Tribal Cultural Resources. Given
implementation of proposed General Plan policies that address archaeological
resources and Mitigation Measure MM-CULT-2, this impact is determined to
be less than significant with mitigation. While there is a potential for
unrecorded cultural resources to occur within the Planning Area,
implementation of proposed General Plan policies aimed at establishing
development processes to avoid disturbance and conducting consultation
early in the development review process would reduce these impacts to a
level that is less than significant.
A1-8 HEALTH HAZARDOUS MATERIALS DIVISION:
The Health Hazardous Materials Division of the Los Angeles
County Fire Department has no comments or requirements
for the project at this time.
Please contact HHMD senior typist-clerk, Perla Garcia at
(323) 890-4035 or Perla.garcia@fire.lacounty.aov if you
have any questions.
Comment acknowledged.
A1-9 If you have any additional questions, please contact this
office at (323) 890-4330.
Comment acknowledged.
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Very truly yours,
MICHAEL Y. TAKESHITA, ACTING CHIEF, FORESTRY DIVISION
PREVENTION SERVICES BUREAU
A2 COUNTY OF LOS ANGELES DEPARTMENT OF PARKS AND RECREATION
A2-1 October 30, 2019
Ms. Grace S. Lee
Senior Planner
City of Diamond Bar, Planning Division
21810 Copley Drive Diamond Bar, CA 91765
Dear Ms. Lee:
NOTICE OF AVAILABILITY OF
DRAFT ENVIRONMENTAL IMPACT REPORT FOR
THE DIAMOND BAR GENERAL PLAN AND CLIMATE ACTION
PLAN 2040
I am writing with regards to the Draft Environmental
Impact Report (DEIR) for the Diamond Bar General Plan
and Climate Action Plan 2040. Located within the Planning
Area are two Los Angeles County Department of Parks and
Recreation (DPR) facilities: Diamond Bar Golf Course and
the proposed Schabarum Extension Trail. Please find below
DPR's comments and questions:
This comment is the salutation of the letter and introduces comments A2-2
through A2-12. Responses to these comments are provided below.
A2-2 Diamond Bar Golf Course
Diamond Bar Golf Course (DBGC) was established as a
public golf course in 1964 and will continue to serve as
such in the foreseeable future. The golf course is protected
public parkland under the Public Park Preservation Act of
1971. The draft General Plan includes a "Community Core"
Comment acknowledged. Compliance with the Park Preservation Act would
need to be addressed as part of any alternative use for the property. This
does not address the adequacy of the adequacy of the Draft EIR ; therefore, no
further response is required.
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focus area that overlays DBGC (page 2-8). The "Community
Core" focus area proposes a mix of uses emphasizing
destination and specialty retail, dining, and entertainment
on the southern portion of the DBGC site. This proposal
does not seem to take into consideration the Park
Preservation Act which contains specific requirements that
must be met in order to convert public parkland into non-
park use(s).
A2-3 Also, the City of Diamond Bar does not have jurisdiction
over this County-owned golf course. Any proposed new
uses on the DBGC site should be discussed and coordinated
with the County. The Los Angeles County Board of
Supervisors has the sole discretion to approve
development on County-owned properties. As such, any
proposed new use(s) on the DBGC would require review
and approval by the Board.
Comment acknowledged. The County as the land owner would obviously
need to be a project sponsor and comply with County processes to consider
the future disposition of the property. This does not address the adequacy of
the adequacy of the Draft EIR; therefore, no further response is required.
A2-4 Schabarum Extension Trail (proposed)
The proposed Schabarum Extension Trail connects the
DPR-operated Rowland Heights Loop Trail in the
unincorporated community of Rowland Heights to San
Bernardino County through preserved open space. This
ten-mile segment of proposed multi-use trail (hiking,
biking, and horseback riding) utilizes portions of unpaved
Southern California Edison right-of-way and provides
intermittent access to communities within the City of
Diamond Bar via recorded trail easements.
Comment acknowledged.
A2-5 Please find below some questions and edits regarding the
discussion of trails in the DEIR.
Page 3.11-12
• Are there any trails planned on the Tres Hermanos
Ranch property?
The General Plan does not propose any trails on the Tres Hermanos Ranch
property.
A2-6 Page 3.11-13 Although the City trails do not include features expressly designed to
accommodate equestrians, equestrians are not precluded from using the
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• Are equestrians accommodated on City trails? If the
proposed Schabarum Extension Trail were developed, it
would become a multi-use trail that would serve hikers,
mountain bikers, and equestrians.
trails. This comment does not address the adequacy of the adequacy of the
Draft EIR; therefore, no further response is required.
A2-7 Table 3.11-6: Existing and Proposed Trail Network (2019)
• Which agency has proposed the Tonner Canyon Trail?
The proposed Tonner Canyon Trail is depicted in the City of Diamond Bar 2011
Parks and Recreation Master Plan, but does not state which agency proposed
the trail. Since the proposed trail is located outside of the City limits, it is
presumed that the information regarding the proposed trail location was
obtained from the County of Los Angeles. This does not address the adequacy
of the adequacy of the Draft EIR; therefore, no further response is required.
A2-8 • Please correct the name of the County trail.
"Schabarum Trail (Skyline Extension)" should be
corrected as "Scharabrum Extension Trail". The
Schabarum Extension and Tonner Canyon Trails are
"Proposed Trails," not "Existing Trails."
Comment acknowledged. The Schabarum Extension Trail and the Tonner
Canyon Trail are identified as proposed trails in Figure 3.11-4. Table 3.11-6
has been revised in Chapter 4 of the Final EIR to reflect this distinction.
A2-9 Page 3.11-14
• Please note that the Schabarum-Skyline Trail is
operated by the County of Los Angeles Department of
Parks and Recreation and is 29.7 miles long.
Comment acknowledged. The Schabarum-Skyline Trail in its entirety is 29.7
miles long. However, the Planning Area only contains a portion of the trail and
does not count all 29.7 miles towards the trail network total mileage.
A2-10 • Please revise the sentence as follows: “The trail allows
recreational users and commuters hikers, mountain
bikers, and equestrians to connect to a variety of other
trails in the area”
The sentence has been revised as proposed in Chapter 4 of the Final EIR.
A2-11 • Please include a note on this page that the
development of staging areas and trailheads will be
considered at strategic locations to accommodate
multi-use trail users.
The proposed revision has been added as a footnote in Chapter 4 of the Final
EIR.
A2-12 Notification
Please note that DPR was not formally notified of the
General Plan update even though the "Community Core"
overlay was proposed on the DBGC site. We only received
Comment acknowledged.
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the Notice of Availability after signing up for e-mail
notification on the project's website several months ago.
A2-13 Thank you for your consideration of our comments. If you
have any questions or wish to discuss further, please
contact Clement Lau, Departmental Facilities Planner, of
my staff at (626) 588-5301 or by email at
clau@parks.lacounty.gov.
Sincerely,
Alina Bokde
Deputy Director
This comment is the closing of the letter and does not address the a dequacy
of the Draft EIR; therefore, no further response is required.
A3 CALIFORNIA DEPARTMENT OF FISH AND WILDLIFE
A3-1 October 30, 2019
Ms. Grace Lee City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
Glee@DiamondBarCA.gov
Subject: Draft Environmental Impact Report for the
Diamond Bar Comprehensive General Plan Update and
Climate Action Plan, City of Diamond Bar, Los Angeles
County
Dear Ms. Lee:
The California Department of Fish and Wildlife (CDFW) has
reviewed the above-referenced Draft Environmental
Impact Report (DEIR) for the Diamond Bar Comprehensive
General Plan Update and Climate Action Plan (Project).
Thank you for the opportunity to provide comments and
recommendations regarding those activities involved in the
Comment acknowledged. This comment is the salutation of the letter and
does not address the adequacy of the Draft EIR; therefore, no further
response is required.
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Project that may affect California fish and wildlife.
Likewise, we appreciate the opportunity to provide
comments regarding those aspects of the Project that
CDFW, by law, may be required to carry out or approve
through the exercise of its own regulatory authority under
the Fish and Game Code.
A3-2 CDFW's Role
CDFW is California's Trustee Agency for fish and wildlife
resources and holds those resources in trust by statute for
all the people of the State [Fish & Game Code, SS 711.7,
subdivision (a) & 1802; Public Resources Code, S 21070;
California Environmental Quality Act (CEQA) Guidelines, S
15386, subdivision (a)]. CDFW, in its trustee capacity, has
jurisdiction over the conservation, protection, and
management of fish, wildlife, native plants, and habitat
necessary for biologically sustainable populations of those
species (Id., S 1802). Similarly, for purposes of CEQA, CDFW
is charged by law to provide, as available, biological
expertise during public agency environmental review
efforts, focusing specifically on projects and related
activities that have the potential to adversely affect state
fish and wildlife resources.
CDFW is also submitting comments as a Responsible
Agency under CEQA (Public Resources Code, S 21069;
CEQA Guidelines, S 15381). CDFW expects that it may need
to exercise regulatory authority as provided by the Fish and
Game Code, including lake and streambed alteration
regulatory authority (Fish & Game Code, S 1600 et seq.).
Likewise, to the extent implementation of the Project as
proposed may result in "take", as defined by State law, of
any species protected under the California Endangered
Species Act (CESA) (Fish & Game Code, S 2050 et seq.), or
state-listed rare plant pursuant to the Native Plant
Comment acknowledged.
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Protection Act (NPPA; Fish & Game Code, Sl 900 et seq.),
CDFW recommends the Project proponent obtain
appropriate authorization under the Fish and Game Code.
A3-3 Project Description and Summary
Objective: The proposed Project is an update to the City of
Diamond Bar (City) General Plan. The General Plan is a
long-term policy document guiding future land use and
policy decisions. The City's current General Plan was
adopted in 1995. In 2016, the City began the process of
comprehensively updating the General Plan.
Location: City of Diamond Bar (Citywide), Los Angeles
County.
Comment acknowledged.
A3-4 Comments and Recommendations
CDFW offers the comments and recommendations below
to assist the City in adequately identifying, avoiding and/or
mitigating the Project's significant, or potentially
significant, direct and indirect impacts on fish and wildlife
(biological) resources. Additional comments or other
suggestions may also be included to improve the
document.
Comment acknowledged. See responses to comments A3-5 through A3-14
below.
A3-5 Project Description and Related Impact Shortcoming
Comment #1: Impacts to Special-Status Plant Species
Issue: Mitigation Measures MM-BIO-I A-C dictate the City's
actions taken to mitigate impacts to any special-status
plants that may be found within the City limits. These
measures refer to US Fish and Wildlife Service (USFWS)
oversight, but do not acknowledge CDFW protocol.
Specific impact: CDFW considers plant communities,
alliances, and associations with a statewide ranking of Sl,
S2, S3 and S4 as sensitive and declining at the local and
regional level (Sawyer et al. 2008). An S3 ranking indicates
there are 21-80 occurrences of this community in existence
The omission of CDFW oversight and mitigation protocols was an unintended
omission, and the inclusion of CDFW in the mitigation measures is included in
Chapter 4 of the Final EIR. The consideration of specific impacts to sensitive
plants, their causes and determination of their significance is discussed in the
Draft EIR.
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in California, S2 has 6-20 occurrences, and Sl has less than
6 occurrences. The Project may have direct or indirect
effects to these sensitive species.
Why impact would occur: Project implementation includes
grading, vegetation clearing for construction, road
maintenance, and other activities that may result in direct
mortality, population declines, or local extirpation of
sensitive plant species.
Evidence impact would be significant: Impacts to special
status plant species should be considered significant under
CEQA unless they are clearly mitigated below a level of
significance. Inadequate avoidance, minimization, and
mitigation measures for impacts to these sensitive plant
species will result in the Project continuing to have a
substantial adverse direct, indirect, and cumulative effect,
either directly or through habitat modifications, on any
species identified as a candidate, sensitive, or special-
status species in local or regional plans, policies, or
regulations, or by CDFW or USFWS.
A3-6 Recommended Potentially Feasible Mitigation Measure(s):
Mitigation Measure #1: CDFW recommends conducting
focused surveys for sensitive/rare plants on-site and
disclosing the results in the DEIR. Based on the Protocols
for Surveying and Evaluating Impacts to Special Status
Native Plant Populations and Natural Communities (CDFW,
2018)
(https://nrm.dfg.ca.qov/FileHandler.ashx?DocumentlD=18
959), a qualified biologist should "conduct surveys in the
field at the time of year when species are both evident and
identifiable. Usually this is during flowering or fruiting."
The final CEQA documentation should provide a thorough
discussion on the presence/absence of sensitive plants on-
To the best of the City’s understanding, CDFW will not accept or validate
focused surveys that are over 1-year old. Insofar as the General Plan update
and its policies are to guide the City’s growth until 2040, focused surveys for
special-status plants at this time would not be useful. Rather, surveys for
sensitive plants at the time the specifics of projects have been detailed, as
indicated in the Draft EIR, is felt to be a more practical approach . The seasonal
timing of such surveys in the future and mitigation for potentially significant
impacts on special-status surveys are discussed in the Draft EIR.
To the extent feasible and practical in the context of a General Plan the MCV
classification system was used to identify natural communities and their
sensitivity in the study area. See also response to comment B3-10.
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site and identify measures to protect sensitive plant
communities from project-related direct and indirect
impacts.
Mitigation Measure #2: In 2007, the State Legislature
required CDFW to develop and maintain a vegetation
mapping standard for the state (Fish & Game Code, §
1940). This standard complies with the National Vegetation
Classification System, which utilizes alliance and
association-based classification of unique vegetation
stands. CDFW utilizes vegetation descriptions found in the
Manual of California Vegetation (MCV), found online at
http://vegetation.cnps.org/. To determine the rarity
ranking of vegetation communities on the Project site, the
MCV alliance/association community names should be
provided as CDFW only tracks rare natural communities
using this classification system.
Mitigation Measure #3: CDFW recommends avoiding any
sensitive natural communities found on the Project. If
avoidance is not feasible, mitigating at a ratio of no less
than 5:1 for impacts to S3 ranked communities and 7:1 for
S2 communities should be implemented. This ratio is for
the acreage and the individual plants that comprise each
unique community. All revegetation/restoration areas that
will serve as mitigation should include preparation of a
restoration plan, to be approved by USFWS and CDFW
prior to any ground disturbance. The restoration plan
should include restoration and monitoring methods;
annual success criteria; contingency actions should success
criteria not be met; long-term management and
maintenance goals; and, a funding mechanism to assure
for in perpetuity management and reporting. Areas
proposed as mitigation should have a recorded
Regarding the use of mitigation ratios see response to comment B3-19.
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conservation easement and be dedicated to an entity
which has been approved to hold/manage lands (Assembly
Bill 1094; Government code, §§ 65965-65968).
A3-7 Comment #2: Inadequate Survey Protocols for Special-
Status Wildlife
Issue: Mitigation Measure MM-BIO-IE indicates that future
projects taking place within the City will require a
clearance survey within one week of initiating ground
disturbance. This measure also states that "[l]f any special-
status animals are found on the site, a qualified biologist(s)
with a CDFG Scientific Collecting Permit shall relocate these
species to suitable habitats within surrounding open space
areas that would remain undisturbed, unless the biologist
determines that such relocation cannot reasonably be
accomplished".
Specific impacts: While MM-BIO-I E does dictate that CDFW
will be consulted regarding relocation, it does not fully
convey the appropriate protocols for a variety of sensitive
species.
Why impacts would occur: Inadequate survey protocols
will likely lead to impacts to a variety of sensitive species as
this process may overlook or fail to identify listed species
and supporting habitat necessary for their survival.
Evidence impact would be significant: Ground clearing and
construction activities could lead to the direct mortality of
a listed species or species of special concern. The loss of
occupied habitat could yield a loss of foraging potential,
nesting sites, basking sites, or refugia and would constitute
a significant impact absent appropriate mitigation. CDFW
considers impacts to CESA-listed and Species of Special
Concern (SSC) a significant direct and cumulative adverse
It is assumed that the practicing professional is aware of the appropriate
survey protocols for various species and/or that such individuals can research
such protocols on the internet. For these reasons, the description of all
possible protocols in the Draft EIR was not included. At the time of a future
project’s specific analysis a species-specific survey and translocation plan will
be prepared and included in the project’s Mitigation Monitoring and
Reporting Plan.
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effect without implementing appropriate avoid and/or
mitigation measures.
Recommended Potentially Feasible Mitigation Measure(s):
Mitigation Measure #1: CDFW recommends that future
proposed projects within the City of Diamond Bar follow
the appropriate survey protocol for a given species, since
the suggested measures, MM-BIO-I seq., do not make
distinctions among the breadth of wildlife species found
throughout the Los Angeles Basin. Based on the listing
status of a given wildlife species found on a future p roject
site, the mitigative response will vary.
The following mitigation measures are suggested by CDFW
for impacts to reptiles:
Mitigation Measure #1: To mitigate impacts to SSC, CDFW
recommends focused surveys for the species. Surveys
should typically be scheduled when these animals are most
likely to be encountered, usually conducted between J une
and July. To achieve 100 percent visual coverage, CDFW
recommends surveys be conducted with parallel transects
at approximately 20 feet apart and walked on-site in
appropriate habitat suitable for each of these species.
Suitable habitat consists of areas of sandy, loose and moist
soils, typically under the sparse vegetation of scrub,
chaparral, and within the duff of oak woodlands.
Mitigation Measure #2: In consultation with qualified
biologist familiar with the life history of each of the SSC, a
relocation plan (Plan) should be developed. The Plan
should include, but not be limited to, the timing and
location of the surveys that will be conducted for this
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species, identify the locations where more intensive survey
efforts will be conducted (based on high habitat
suitability); identify the habitat and conditions in any
proposed relocation site(s); the methods that will be
utilized for trapping and relocating the individuals of this
species; and the documentation/recordation of the
number of animals relocated. CDFW recommends the Plan
be submitted to the Lead Agency for approval 60 days prior
to any ground disturbing activities within potentially
occupied habitat.
Mitigation Measure #3: The Plan should include specific
survey and relocation efforts that occur during
construction activities for the activity period of these
reptiles (generally March to November) and for periods
when the species may be pres ent in the work area but
difficult to detect due to weather conditions (generally
December through February). Thirty days prior to
construction activities in coastal scrub, chaparral, oak
woodland, riparian habitats, or other areas supporting this
species, qualified biologists should conduct surveys to
capture and relocate individual reptiles to avoid or
minimize take of these special-status species. The Plan
should require a minimum of three surveys conducted
during the time of year/day when these species most likely
to be observed. Individuals should be relocated to nearby
undisturbed areas with suitable habitat.
Mitigation Measure #4: If construction is to occur during
the low activity period (generally December through
February), surveys should be conducted prior to this period
if possible. Exclusion fencing should be placed to limit the
potential for re-colonization of the site prior to
construction. CDFW further recommends a qualified
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biologist be present during ground-disturbing activities
immediately adjacent to or within habitat, which supports
populations of this species.
A3-8 The following mitigation measures are suggested by CDFW
for impacts to nesting birds:
Mitigation Measure #1: To protect nesting birds that may
occur on-site, CDFW recommends that the final
environmental document include a measure that no
construction shall occur from February 15 through August
31. If construction is unavoidable during February 15
through August 31, a qualified biologist shall complete a
survey for nesting bird activity within a 500-foot radius of
the construction site. The nesting bird surveys shall be
conducted at appropriate nesting times and concentrate
on potential roosting or perch sites. If any nests of birds of
prey are observed, these nests shall be designated an
ecologically sensitive area and protected (while occupied)
by a minimum 500-foot radius during project construction.
The following mitigation measures are suggested by CDFW
for impacts to raptors:
Mitigation Measure #1: To protect nesting birds that may
occur on-site, CDFW recommends that the final
environmental document include a measure that no
construction shall occur from February 15 through August
31. If construction is unavoidable during February 15
through August 31, a qualified biologist shall complete
surveys for nesting bird activity the orders Falconiformes
and Strigiformes (raptors and owls) within a 500 -foot
radius of the construction site. The nesting bird surveys
shall be conducted at appropriate nesting times and
concentrate on potential roosting or perch sites. If an y
Mitigation consistent with the comment is provided for as MM-BIO-1G on
page 3.3-50 of the Draft EIR. Protected species that have been observed or
have a moderate to high potential to occur in the study area are identified in
Table 3.3-4 in the Draft EIR. The fact that taking or possessing protected
species is unlawful is discussed on page 3.3-45 of the Draft EIR.
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nests of birds of prey are observed, these nests shall be
designated an ecologically sensitive area and protected
(while occupied) by a minimum 500-foot radius during
project construction. Pursuant to FGC Sections 3503 and
3503.5, it is unlawful to take, possess, or needlessly
destroy the nest or eggs of any bird or bird-of-prey.
Mitigation Measure #2: CDFW cannot authorize the take of
any fully protected species as defined by state law. State
fully protected species may not be taken or possessed at
any time and no licenses or permits may be issued for its
take except for collecting those species for necessary
scientific research and relocation of the bird species for
protection of livestock (Fish & G. Code, §§ 3511, 4700,
5050, 5515). CDFW has advised the Permittee that take of
any species designated as fully protected under the Fish
and Game Code is prohibited. CDFW recognizes that
certain fully-protected species are documented to occur
on, or in, the vicinity of the Project area, or that such
species have some potential to occur on, or in, the vicinity
of the Project area, due to the presence of suitable habitat.
A3-9 The following mitigation measures are suggested by CDFW
for impacts to bats:
Mitigation Measure #1: The CEQA document should
provide a thorough discussion of potential impacts to bats
from construction and operation of the Project to
adequately disclose potential impacts and to identify
appropriate avoidance and mitigation measures.
Mitigation Measure #2: Measures to mitigate for impacts
to bats should include preconstruction surveys to detect
species, use of bat roost installations, and preparation of a
Mitigation measures consistent with those presented in the comment to
prevent potentially significant impact to bat species are provided in MM-BIO-
1I, MM-BIO-1J and MM-BIO-1K on pages 3.3-50 and 3.3-51 of the Draft EIR.
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Comment ID Comment Response
bat protection and relocation plan to be submitted to
CDFW for approval prior to commencement of project
activities.
Mitigation Measure #3: CDFW recommends the Project
avoid removal of trees that may be used by bats or avoid
buildings or other occupied habitat for any species of bat. If
bats cannot be avoided by Project activities and a bat
specialist determines that roosting bats may be present at
any time of year, it is preferable to push any tree down
using heavy machinery rather than felling the tree with a
chainsaw. To ensure the optimum warning for any roosting
bats that may still be present, the tree should be pushed
lightly two to three times, with a pause of approximately
30 seconds between each nudge to allow bats to become
active. The tree should then be pushed to the ground
slowly. The bat specialist should determine the optimal
time to disturb occupied bat habitat to maximize bats
escaping during low light levels. Downed trees should
remain in place until they are inspected by a bat specialist.
Trees that are known to be bat roosts should not be sawn -
up or mulched immediately. A period of at least 24 hours
(preferably 48 hours) should elapse prior to such
operations to allow bats to escape. Bats should be allowed
to escape prior to demolition of buildings. This may be
accomplished by placing one-way exclusionary devices into
areas where bats are entering a building that allow bats to
exit but not enter the building. In addition, CDFW
recommends that the Project include measures to ensure
that bat habitat remains available for evicted bats or loss of
bat habitat resulting from the Project, including
information on the availability of other potential roosts
that could be used by bats within protected open space on
or near the Project site.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
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Comment ID Comment Response
A3-10 Comment #3: Impacts to CESA-Listed Species
Issue: There are multiple listed species with the potential
to occur on the Project site.
Specific Impacts: Project related activities, such as grading,
road construction, or housing construction could lead to
the direct or indirect mortality of listed animal and/or plant
species.
Why impact would occur: Take of special status plant
species, including ESA and CESAlisted species, may occur
without adequate detection, avoidance and mitigation
measures.
Evidence impacts would be significant: CDFW considers
adverse impacts to special status species protected by
CESA and the federal Endangered Species Act (ESA, 16
U.S.C. §1531 et seq.), for the purposes of CEQA, to be
significant without mitigation. As to CESA, take of any state
endangered, threatened, candidate species, or listed rare
plant species pursuant to the NPPA that results from the
Project is prohibited, except as authorized by state law
(Fish and Game code, §§ 2080, 2085; Cal. Code Regs., tit.
14, §786.9). Take is defined in Section 86 of the Fish and
Game Code as "hunt, pursue, catch, capture, or kill, or
attempt to hunt, pursue, catch, capture, or kill". Project
impacts may result in substantial adverse effects, either
directly or through habitat modifications, on a species
protected under CESA.
Recommended Potentially Feasible Mitigation Measure(s):
Mitigation Measure #1: If the Project, Project construction,
or any Project-related activity during the life of the Project
Comment acknowledged. The Draft EIR includes discussions of such special-
status species on pages 3.3-36 through 3.3-51 of the Draft EIR.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
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Comment ID Comment Response
will result in take of a plant or animal species designated as
rare, endangered or threatened, or a candidate for listing
under CESA, CDFW recommends that the Project
proponent seek appropriate take authorization under CESA
prior to implementing the Project. Appropriate
authorization from CDFW may include an I TP or a
consistency determination in certain circumstances, among
other options (Fish and Game Code §§ 2080.1, 208, subds.
[b],[c]). Early consultation is encouraged, as significant
modification to a project and mitigation measures may be
required in order to obtain CESA authorization. Revisions
to the Fish and Game Code, effective January 1998, may
require CDFW issue a separate CEQA document for the
issuance of an ITP unless the Project CEQA document
addresses all Project impacts to CESA-listed species and
specifies a mitigation monitoring and reporting program
that will meet the fully mitigated requirements of an ITP.
For these reasons, biological mitigation monitoring and
reporting proposals should be of sufficient detail and
resolution to satisfy the requirements for an ITP.
A3-11 Comment #4: Accuracy of Tree Surveys
Issue: There are conflicting tree surveys for the City of
Diamond Bar, one presented by the City (Diamond Bar
Environmental Impact Report 2040) and one provided by a
concerned group of citizens (Biological Resources Report
for Open Space & Conservation Element Diamond Bar
General Plan Update). Between these sources, there is
uncertainty in the accuracy of vegetation surveys, their
accounting of oak and walnut woodlands, and the resulting
mitigation.
Specific Impact: The classifications of oak woodlands,
walnut woodlands, riparian woodlands, and California
walnut/Coast live oak woodland are inconsistent among
See responses to comments A3-6 and B3-9.
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Comment ID Comment Response
the publicly available surveys provided in support of the
DEIR. Based on the tree surveys provided for a given
project, the potential impacts and their subsequent
mitigation may vary greatly.
Why impact would occur: If a habitat is misidentified, then
the mitigative restored/replaced habitat may be of a
different type, resulting in a habitat-type conversion and
loss of the original habitat.
Evidence impact would be significant: CDFW is concerned
that inaccurate surveys of tree species as part of this
Project would contribute to the degradation of natural
open space or riparian habitats found within the City limits.
CDFW is concerned that by not requiring all native trees
and plants be replaced by similar native tree and plant
species, the replacement trees would not be fully
mitigating the function and value of the impacted native
tree species.
In 2007, the State Legislature required CDFW to develop
and maintain a vegetation mapping standard for the state
(Fish & Game Code, § 1940). This standard complies with
the National Vegetation Classification System, which
utilizes alliance and association based classification of
unique vegetation stands. CDFW utilizes vegetation
descriptions found in the Manual of California Vegetation
(MCV), found online at http://vegetation.cnps.org/. To
determine the rarity ranking of vegetation communities on
the Project site, the MCV alliance/association community
names should be provided as CDFW only tracks rare
natural communities using this classification system.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
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Recommended Potentially Feasible Mitigation Measure(s):
Mitigation Measure #1: Prior to completion of the Final
Environmental Impact Report, the discrepancies between
publicly available tree and vegetation surveys for the study
area should be resolved by classifying vegetation according
to the MCV.
Comment #5: Inadequate Oak and Walnut Woodlands
Mitigation
Issue: The DEIR states that oak and walnut trees will be
planted or transplanted, at a ratio of at least 1:1.
• Page 3.3-54 states that future project mitigation will
"Acquire oak woodland habitat that is comparable to
the habitat that was impacted at a ratio of 1:1."
• Page 3.3-55 states that future project mitigation will
"Acquire walnut woodland habitat that is comparable to
Specific Impact: Oak woodland and walnut woodland
alliances are considered rare communities and should be
mitigated as an ecosystem. Oak and Walnut woodlands are
a community that includes the trees, as well as any
understory plants, duff, dead logs, etc. Removal or thinning
of an understory in woodland directly impacts the function
of the entire woodland.
Why impact would occur: Based on the tree surveys
provided for a given project, the potential impacts and
their subsequent mitigation may vary greatly. If a habitat is
misidentified, then the mitigative restored/replaced
habitat may be of a different type, resulting in a habitat -
type conversion and loss of the original habitat.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
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Evidence Impact would be significant: A functioning
woodland system does not solely include trees. There is an
important understory component which needs to be
figured into the impact analysis and mitigation proposal to
fully mitigate impacts to rare and sensitive CDFW plant
communities, such as oak woodlands and walnut
woodlands. The DEIR does not describe what species these
trees are, where they occur, how many will be removed, or
how large they are. CDFW is unable to concur with any
proposed mitigation measures without knowing first what
will be impacted.
Correct mapping of recognized vegetation alliances is vital
to disclose actual acreage-based impacts to these tree-
dominated vegetation community, as well as ensure they
are adequately mitigated. CDFW was unable to verify the
validity of several vegetation communities listed in the
DEIR as recognized alliances, therefore unable to
determine if they are sensitive vegetation communities.
Including the scientific names for alliances as well as a
thorough description of the membership requirements of
each alliance would be helpful for validating the
assessment completed. Each future project within the City
should provide this information to CDFW for review in an
environmental document.
A3-12 Recommended Potentially Feasible Mitigation Measure(s):
Mitigation Measure #1: CDFW recommends avoiding
impacts to the oak or walnut woodland communities. If
avoidance is not feasible, the City should minimize impacts
to the maximum extent possible. Any impacts to the oak or
walnut woodland communities should b e mitigated at a
minimum 10 acres of preservation/restoration for every 1
acre of impact. All mitigation should be held to quantifiab le
success criteria, including species diversity, species
The City has an adopted Tree Preservation and Protection Ordinance.
However, the suggested mitigation contained in the comment are noted and
will be considered when the existing ordinance is modified.
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richness, abundance, percent cover, and non-native cover
below 5 percent. Success criteria should be based on the
composition of the vegetation communities being
impacted. Success should not be determined until the site
has been irrigation-free and the metrics for success have
remained stable for at least 5 years.
Mitigation Measure #2: CDFW recommends off-site habitat
preservation of rare and sensitive vegetation communities
(i.e., oak woodland, walnut woodland, etc.) at a ratio of at
least 10:1 for impacts to these resources. Additionally,
planting more trees in the existing on-site habitat at an
excessive density should be avoided as it could result in an
impact to that habitat.
Mitigation Measure #3: For all native trees not classified as
a rare vegetation community according to MCV, CDFW
recommends mitigating for those trees impacted by the
Project at a 5:1 ratio for both the acreage of impact as well
as the number of trees.
Mitigation Measure #4: CDFW recommends that all open
space preservation/mitigation land be protected in
perpetuity with minimal human intrusion by recording and
executing a perpetual conservation easement in favor of an
approved agent dedicated to conserving biological
resources. In addition, CDFW recommends all mitigation
lands be owned or managed by an entity with experience
in managing habitat. Mitigation lands should be owned or
managed by a conservancy or other land management
company to allow for legal remedies should trespass and
clearing/damage occur. A management and monitoring
plan, including a funding commitment, should be
developed for any conserved land, and implemented in
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perpetuity to protect existing biological functions and
values.
A3-13 Comment #6: Impacts to Streams
Issue: Mitigation Measure MM-BIO-3 Jurisdictional Waters
discusses the need for consultation with regulating
agencies regarding impacts to riparian resources and
potential mitigation but does not indicate the need for
notification for a Lake and Streambed Alteration
Agreement with CDFW.
Specific impacts: The Project may result in the loss of
streams and associated watershed function and biological
diversity. Grading and construction activities will likely alter
the topography, and thus the hydrology, of the Project site.
Why impacts would occur: Ground disturbing activities
from grading and filling, water diversions and dewatering
would physically remove or otherwise alter existing
streams or their function and associated riparian habitat
on the Project site. Downstream streams and associated
biological resources beyond the Project development
footprint may also be impacted by Project related releases
of sediment and altered watershed effects resulting from
Project activities.
Evidence impacts would be significant: The Project may
substantially adversely affect the existing stream pattern of
the Project site through the alteration or diversion of a
stream, which absent specific mitigation, could result in
substantial erosion or siltation on site or off site of the
project.
Recommended Potentially Feasible Mitigation Measure(s):
The Draft EIR recognizes the presence of CDFG regulated drainages in the
study area on page 3.3-8. Section 1602 of the California Fish and Game Code
identifies related regulatory constraints of these resources on page 3.3-35.
Impacts associated with the development of these resources, including
mitigation are discussed on pages 3.3-51 through 3.3-53.
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Mitigation Measure #1: The Project may result in the
alteration of streams. For any such activities, the Project
applicant (or "entity') must provide written notification to
CDFW pursuant to section 1600 et seq. of the Fish an d
Game Code. Based on this notification and other
information, CDFW determines whether a Lake and
Streambed Alteration Agreement (LSA) with the applicant
is required prior to conducting the proposed activities. A
notification package for a LSA may be obtained by
accessing CDFW's web site at
www.wildlife.ca.qov/habcon/1600.
CDFW's issuance of an LSA for a project that is subject to
CEQA will require CEQA compliance actions by CDFW as a
Responsible Agency. As a Responsible Agency, CDFW may
consider the CEQA document of the Lead Agency for the
Project. However, the DEIR does not meet CDFW's
standard at this time. To minimize additional requirements
by CDFW pursuant to section 1600 et seq. and/or under
CEQA, the CEQA document should fully identify the
potential impacts to the stream or riparian resources and
provide adequate avoidance, mitigation, monitoring and
reporting commitments for issuance of the LSA.
Mitigation Measure #2: Any LSA permit issued for the
Project by CDFW may include additional measures
protective of streambeds on and downstream of the
Project. The LSA may include further erosion and pollution
control measures. To compensate for any on-site and off-
site impacts to riparian resources, additional mitigation
conditioned in any LSA may include the following:
avoidance of resources, on-site or off-site creation,
enhancement or restoration, and/or protection and
management of mitigation lands in perpetuity.
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Comment ID Comment Response
A3-14 Filing Fees
The Project, as proposed, would have an impact on fish
and/or wildlife, and assessment of filing fees is necessary.
Fees are payable upon filing of the Notice of Determination
by the Lead Agency and serve to help defray the cost of
environmental review by CDFW. Payment of the fee is
required in order for the underlying Project approval to be
operative, vested, and final. (Cal. Code Regs, tit. 14, §
753.5; Fish & Game Code, § 711.4; Pub. Resources code, §
21089).
Comment acknowledged.
A3-15 Conclusion
We appreciate the opportunity to comment on the Project
to assist the City of Diamond Bar in adequately analyzing
and minimizing/mitigating impacts to biological resources.
CDFW requests an opportunity to review and comment on
any response that the City has to our comments and to
receive notification of any forthcoming hearing date(s) for
the Project [CEQA Guidelines; §15073(e)]. If you have any
questions or comments regarding this letter, please
contact Andrew Valand, Environmental Scientist, at
Andrew.Valand@wildlife.ca.qov or (562) 342-2142.
Sincerely,
Erinn Wilson
Environmental Program Manager I
The comment is the closing of the letter. Comments regarding the adequacy
of the Draft EIR are addressed above.
A3-16 References:
California Department of Fish and Wildlife [CDFW]. March
20, 2018. Protocols for Surveying and Evaluating Impacts to
Special Status Native Plant Populations and Natural
Communities (see
https://www.wildlife.ca.gov/Conservation/Plants).
The comment provides references to the comments made in the letter,
addressed in comments A3-5 through A3-13. No response is required.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
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Table 3-1: Response to Comments Matrix
Comment ID Comment Response
Dyett & Bhatia. September 2019. Diamond Bar
Environmental Impact Report 2040. Public Review Draft.
September 2019.
Hamilton, Robert. February 2019. Biological Resources
Report for Open Space & Conservation Element Diamond
Bar General Plan Update.
National Research Council. 1995. Science and the
Endangered Species Act. Washington, DC: The National
Academies Press. https://doi.org/10.17226/4978.
Sawyer, J.O., Keeler Wolf, T., and Evens J.M. 2008. A
manual of California Vegetation, 2nd ed. ISBN 978 0
943460 49 9.
A4 CALTRANS DISTRICT 7
A4-1 October 31, 2019
Ms. Grace Lee City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
RE: Diamond Bar Comprehensive General Plan Update and
Climate Action Plan — Draft Environmental Impact Report
(DEIR)
SCH # 2018051066
GTS # 07-LA-2018-02837
Vic. LA-57/PM: R 1.184 - 6.08
LA-60/PM: R 22.064 - R 27.472
Dear Ms. Grace Lee:
This comment is the opening of the letter and provides information regarding
Caltrans’ responsibility to respond to the Draft EIR. See responses to
comments A4-2 through A4-8 below.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
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Comment ID Comment Response
Thank you for including the California Department of
Transportation (Caltrans) in the environmental review
process for the above referenced project. The proposed
project involves updating the city's General Plan and
Climate Action Plan, as well as various elements of the
General Plan.
The nearest State facilities to the proposed project are
State Route 57 and State Route 60.
Based on the information received in the Draft
Environmental Impact Report for the Diamond Bar
Comprehensive General Plan Update and Climate Action
Plan, Caltrans has the following comments:
A4-2 Caltrans supports the implementation of complete streets
and active transportation safety improvements, especially
those represented in the Transportation section of the
Draft General Plan. Some of Caltrans' recommended
improvements include, but are not limited to, measures
such as road diets, bike lanes, and other traffic calming
elements to promote sustainable transportation. As
mentioned in Caltrans' previous Notice of Perpetration
(NOP) comment letter, the Federal Highway Administration
(FHWA) recognizes the road diet treatment as a proven
safety countermeasure, and the cost of a road diet can be
significantly reduced if implemented in tandem with
routine street resurfacing.
Comment acknowledged. The General Plan includes multiple policies in
Chapter 4, Circulation aimed at promoting sustainable transportation
including, but not limited to, traffic calming measures, increased bicycle and
pedestrian infrastructure, and electric vehicle infrastructure.
A4-3 When considering implementation of innovative bicycle
infrastructure, the City may consult resources such as the
National Association of Transportation Officials' (NACTO)
Urban Bikeway Design Guide, or FHWA Separated Bike
Lane Planning and Design Guide, to assist in the design
process. Caltrans formally endorsed the NACTO Guide in
Comment acknowledged.
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2014 and the FHWA released its guide in 2015. Also, the
State's Highway Design Manual now contains provisions for
protected bike lanes under "Design Information Bulletin
Number 89: Class [V Bikeway Guidance (Separated
Bikeways/ Cycle Tracks)."
A4-4 Regional and State level policy goals related to sustainable
transportation seek to reduce the number of trips made by
driving, reduce greenhouse gas emissions, and encourage
alternative modes of travel. Caltrans' Strategic
Management Plan has set a target of tripling trips made by
bicycling, and doubling trips made by walking and public
transit by 2020. The Strategic Plan also seeks to achieve a
sizable reduction in statewide, per capita, vehicle miles
traveled (VMT) by 2020. Similar goals are included in
Caltrans' 2040 Transportation Plan, and the Southern
California Association of Governments' Regional
Transportation Plan. Statewide legislation such as AB 32
and SB 375 echo the need to pursue more sustainable
development and transportation. The aforementioned
policy goals related to sustainability and climate change
can only be achieved with support from local agencies on
all levels of planning.
Comment acknowledged. The Diamond Bar General Plan includes numerous
goals and policies that support these efforts.
A4-5 Caltrans is moving towards replacing Level of Service (LOS)
with Vehicle Miles Traveled (VMT) when evaluating traffic
impact. Per SB 743 requirements, Caltrans supports the
City's efforts towards developing these metrics and any
development that may reduce VMT. As a reminder, Senate
Bill 743 (2013) mandates that VMT be used as the primary
metric in identifying transportation impacts of all future
development projects under CEQA, starting July 1, 2020.
For information on determining transportation impacts in
terms of VMT on the State Highway System, see the
Technical Advisory on Evaluating Transportation Impacts in
CEQA by the California Governor's Office of Planning and
Comment acknowledged. Per SB 743 requirements and in accordance with
2019 CEQA Appendix G criteria, the following threshold of significance is used
to determine if the proposed General Plan has an impact under the terms of
Criteria 2: “A significant impact would occur if the proposed General Plan
Update increases the Vehicle Miles Traveled (VMT) per person above the
baseline conditions.” (page 3.12-31, Impact 3.12-2).
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
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Research, dated December 2018:
http://opr.ca.gov/docs/20190122-743
Technical_Advisory.pdf.
A4-6 With regards to parking, Caltrans supports reducing the
amount of parking whenever possible. Research on parking
suggests that abundant car parking enables and
encourages driving. Research looking at the relationship
between land-use, parking, and transportation indicates
that the amount of car parking supplied can undermine a
project's ability to encourage public transit and active
modes of transportation. For any future project to better
promote public transit and reduce vehicle miles traveled,
we recommend the implementation of Transportation
Demand Management (TDM) strategies as an alternative to
building excessive parking.
Comment acknowledged. The General Plan includes multiple policies that
would reduce parking minimums, improve curbside management, and
support transportation demand programs in order to promote multi-modal
transportation and reduce VMT. Policies are cited in Chapter 3.12 and
Chapter 3.5: Air Quality, Climate Change, and Greenhouse Gases.
A4-7 Due to the sensitivity of wildfires in Los Angeles County,
Caltrans suggests the project please consider planning
future implementation/construction in a way that will not
impede the ability to perform an emergency evacuation.
Please consider taking steps to ensure that evacuation
roadways are free of any debris or project equipment and
are accessible to the public/emergency vehicles at all
times. As power outages become more common due to
wildfire prevention, please consider alternative power
sources for emergency evacuation route streetlights and
traffic signals.
Comment acknowledged. The Draft EIR concludes that implementation of the
General Plan would not result in inadequate emergency access in Impacts 3.7-
6 (page 3.7-40) and 3.12-4 (page 3.12-37).
A4-8 Storm water run-off is a sensitive issue for Los Angeles and
Ventura counties. For any future projects Caltrans supports
designs that discharge clean run-off water and/or
incorporate green design elements that can capture storm
water. Incorporating measures such as, but not limited to,
permeable pavement, landscaping, and trees reduce urban
water run-off and encourage a healthy, sustainable
environment.
Comment acknowledged. The General Plan includes multiple policies that
would limit run-off by requiring new development to incorporate Best
Management Practices and Low Impact Development Strategies and requiring
the implementation of a stormwater pollution prevention plan. Additionally,
the General Plan provides policies that encourage sustainability in site design
and protect waterways from pollution and degradation. Chapter 3.8:
Hydrology and Water Quality concludes that impacts related to stormwater
run-off would be less than significant.
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A4-9 If you have any questions or concerns regarding these
comments, please contact project coordinator, Reece Allen
at ece.allen@dot.ca.gov and refer to 07 -LA-2018-02837.
Sincerely,
MIYA EDMONSON
IGR/CEQA Branch Chief
This comment is the closing of the letter and does not address the adequacy
of the Draft EIR; therefore, no further response is required.
A5 LOS ANGELES COUNTY METROPOLITAN TRANSPORTATION AUTHORITY (METRO)
A5-1 October 31, 2019
Grace S. Lee, Senior Planner
City of Diamond Bar, Planning Division
21810 Copley Drive
Diamond Bar, CA 91765
Sent by Email: glee@diamondbarca.gov
RE: Diamond Bar General Plan Update and Climate
Action Plan (CAP) – Draft Environmental Impact Report
(DEIR)
Dear Ms. Lee:
Thank you for coordinating with the Los Angeles County
Metropolitan Transportation Authority (Metro) regarding
the proposed General Plan Update and CAP (Plan), located
in the City of Diamond Bar (City). Metro is committed to
working with local municipalities, developers, and other
stakeholders across Los Angeles County on transit-
supportive developments to grow ridership, reduce driving,
and promote walkable neighborhoods. Transit Oriented
Communities (TOCs) are places (such as corridors or
neighborhoods) that, by their design, allow people to drive
Comment acknowledged. This comment is the salutation of the letter and
provides information on Metro’s commitment to supporting Transit Oriented
Communities.
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less and access transit more. TOCs maximize equitable
access to a multi-modal transit network as a key organizing
principle of land use planning and holistic community
development.
A5-2 Within the Plan area, Metro funds Metrolink commuter rail
service operated by the Southern California Regional Rail
Authority (SCRRA). The purpose of this letter is to briefly
describe the proposed Plan (based on the DEIR’s project
description), outline recommendations from Metro
concerning issues that are germane to our agency’s
statutory responsibility in relation to Metrolink facilities
and services that may be affected by the proposed Plan,
and help identify opportunities in the Plan to support
transit ridership.
Comment acknowledged.
A5-3 Plan Description
The Plan includes the Diamond Bar Plan 2040, which is a
long-term document expressing the goals, objectives, and
policies necessary to guide the community toward
achieving its vision over a 20-year period. The Plan also
includes a CAP, which is a comprehensive plan for
addressing a community’s greenhouse gas (GHG)
emissions.
Comment acknowledged.
A5-4 Transit Service Considerations
1. Coordination Resource: To improve coordination
between the City, adjacent development and Metro,
Metro would like to provide the City with a user-
friendly resource, the Metro Adjacent Development
Handbook (attached), which provides an overview of
common concerns for development adjacent to
Metrolink ROW. This document and additional
resources are available at www.metro.net/devreview/.
Metro encourages the City to provide this document as
Comment acknowledged. The Metro Adjacent Handbook is included in the
Final EIR as a reference for all development projects adjacent to Metro ROW.
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a resource to all development projects adjacent to
Metro ROW.
A5-5 2. Rail Operations, Noise & Vibration: Metrolink operates
within the Plan area, serving Industry Station. Metrolink
operates in and out of revenue service, 24 hours a day,
seven days a week. Considering the proximity of the
Plan area to Metrolink, it is expected that rail
operations may produce noise and vibration.
Comment acknowledged. Railroad sound levels were not measured for the
Draft EIR; ambient noise measurements were conducted for the General Plan
Update to characterize the general ambient noise environment in the
Program Area; however, not for impact assessment in the Program EIR.
Accordingly, as discussed on page 3.10-25, specific details on future railway
expansions or improvements are unknown at this time, neither are the
specific noise sources that might occur in conjunction with development of
land uses near the railway under the Proposed Plan. Therefore, railway noise
and vibration impacts are discussed on a qualitative basis. Policies within the
General Plan Update (e.g., PS-P-52) take into consideration the siting of
sensitive receptors near potential noise generators and would limit the
exposure of sensitive receptors to any existing railway noise. Furthermore,
the proposed General Plan Update does not include any railway upgrades or
improvement that would increase train volumes or number of tracks.
A5-6 3. Plan Policies to address Transit: To further address the
land use and noise compatibility of future development
in the vicinity of Industry Station, Metro recommends
that the Plan include policies to require future
development projects in the Station’s vicinity to record
a notice to property owners and tenants to advise of
the presence of railway noise and vibration sources.
Any noise mitigation required for future development
projects must be borne by the project applicants and
not Metrolink.
Policy revisions and additions are not relevant for the purposes of the Final
EIR, and this comment does not address the adequacy of the Draft EIR. Goal
LU-G-21 states “Ensure that new development is sensitive to the scale,
density, and massing of adjacent residential uses and potential sources of
noise and air pollution.” Policy LU-P-34 states “Ensure that development
evaluates and mitigates to extent practical noise and air quality issues related
to the proximity of the SR-60 and Metrolink.”
A5-7 4. Climate Action Planning: Metro encourages the City to
review the Plan’s consistency with Metro’s 2019
Climate Action and Adaptation Plan (CAAP) and the
Southern California Association of Governments’ 2020-
2045 Regional Transportation Plan/Sustainable
Communities Strategy to ensure the Plan will not
conflict with those plans. Metro’s 2019 CAP is available
at
Chapter 3.5: Energy, Climate Change, and Greenhouse Gases concludes that
the General Plan policies and land use designations, as well as the Climate
Action Plan, would be consistent with the 2016-2040 SCAG RPT/SCS under
Impacts 3.5-2 and 3.5-4. The 2020-2045 Draft RPT/SCS was published after
the Public Review period for the Draft EIR closed. The General Plan and
Climate Action Plan would not conflict with the Metro 2019 CAAP or the SCAG
2020-2045 RTP/SCS.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-41
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
http://media.metro.net/projects_studies/sustainability
/images/Climate_Action_Plan.pdf.
A5-8 Transit Orientation Considerations
Considering the Plan area’s proximity to the Industry
Station, Metro would like to identify the potential
synergies associated with transit-oriented development:
1. Transit-Supportive Planning: To achieve Metro’s
program objectives, Metro strongly recommends that
the City review the Transit-Supportive Planning Toolkit
which identifies 10 elements of transit-supportive
places and applied collectively, has been shown to
reduce vehicle miles traveled by establishing
community-scaled density, diverse land use mix,
combination of affordable housing, and infrastructure
projects for pedestrians, bicyclists, and people of all
ages and abilities. This resource is available at
https://www.metro.net/projects/tod-toolkit.
Comment acknowledged.
A5-9 2. Land Use: Metro supports development of commercial
and residential properties near transit stations and
understands that increasing development near stations
represents a mutually beneficial opportunity to increase
ridership and enhance transportation options for the
users of developments. Metro encourages the City to
be mindful of the Plan’s proximity to the Industry
Station, including orienting pedestrian pathways
towards the station.
Comment acknowledged. Policy LU-P-30 would “Ensure that building
frontages and streetscaping define the public realm and encourage pedestrian
activity and comfort with a mix of building patterns, ground floor
transparency for commercial uses, and pedestrian-oriented elements such as
building entrances and public outdoor spaces.” Policy LU-P-31 would
“Promote convenient, attractive, and safe pedestrian, bicycle, and transit
connections between the Transit-Oriented Mixed Use neighborhood and
surrounding neighborhoods and other destinations within Diamond Bar such
as schools, the Town Center, and parks.”
A5-10 3. Transit Connections:
a. Transfer Activity: Given the Plan’s proximity to
the Industry Station, proposed project design
should consider and accommodate transfer
activity between bus and rail lines that will
occur along the sidewalks and public spaces.
Metro has completed the Metro Transfers
Comment acknowledged. Policy revisions and additions are not relevant for
the purpose of the Final EIR. Policy LU-P-31 would “Promote convenient,
attractive, and safe pedestrian, bicycle, and transit connections between the
Transit-Oriented Mixed Use neighborhood and surrounding neighborhoods
and other destinations within Diamond Bar such as schools, the Town Center,
and parks.” Policy LU-P-41 would “Maximize accessibility for transit,
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-42
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
Design Guide, a best practices document on
transit improvements. This can be accessed
online at
https://www.metro.net/projects/systemwided
esign.
automobiles, cyclists, and pedestrians to the Town Center from surrounding
neighborhoods, the Metrolink station, and other Diamond Bar destinations.”
A5-11 b. Access: The Plan should address first-last mile
connections to transit, encouraging
development that is transit-accessible with
bicycle and pedestrian-oriented street design
that connects transportation with housing and
employment centers. The City is also
encouraged to support these connections with
wayfinding signage inclusive of all modes of
transportation. For reference, please review
the First Last Mile Strategic Plan, authored by
Metro and the Southern California Association
of Governments (SCAG), available on-line at:
http://media.metro.net/docs/sustainability_pa
th_design_guidelines.pdf
Comment acknowledged. Multiple policies within the General Plan encourage
transit-accessible development, pedestrian-oriented street design, and first-
and last-mile connectivity. Policy CR-P-49 would “Create additional
pedestrian, bus, and bikeway connections to the Metrolink station to address
first- and last-mile (FMLM) connectivity and make it easier to travel to
between the station and surrounding neighborhoods.”
A5-12 4. Active Transportation: Metro strongly encourages the
City to install project features that help facilitate safe
and convenient connections for pedestrians, people
riding bicycles, and transit users to/from the Industry
Station and nearby destinations. The City should
consider requiring the installation of such features as
part of the conditions of approval for proposed
projects. These features can include the following:
a. Walkability: The installation of wide sidewalks,
pedestrian lighting, a continuous canopy of
shade trees, enhanced crosswalks with ADA-
compliant curb ramps, and other amenities
along all public street frontages of the
development site to improve pedestrian safety
and comfort to access the nearby rail station.
Comment acknowledged. The General Plan includes multiple policies that
would ensure safe and convenient connections for pedestrians, bicyclists, and
transit users in the Land Use and Circulation chapters. See responses to
comments A5-9 through A5-11.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-43
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
b. Bicycle Use: The provision of adequate short-
term bicycle parking, such as ground level
bicycle racks, and secure, access-controlled,
enclosed long-term bicycle parking for
residents, employees and guests. Bicycle
parking facilities should be designed with best
practices in mind, including highly visible siting,
effective surveillance, easy to locate, and
equipment installed with preferred spacing
dimensions, so they can be safely and
conveniently accessed.
A5-13 5. Parking: Metro encourages the incorporation of transit-
oriented, pedestrian-oriented parking provision
strategies such as the reduction or removal of minimum
parking requirements for specific areas and the
exploration of shared parking opportunities. These
strategies could be pursued to reduce automobile-
orientation in design and travel demand.
Comment acknowledged. Policy LU-P-32 states “In conjunction with new
development, implement an overall parking strategy for the Transit-Oriented
Mixed Use neighborhood, including consolidation of smaller parking lots and
district-wide management of parking resources.” Policy LU-P-33 states
“Consider amendments to the Development Code parking regulations as
needed to allow lower parking minimums for developments with a mix of
uses with different peak parking needs, as well as developments that
implement enforceable residential parking demand reduction measures, such
as parking permit and car share programs.”
A5-14 Metro looks forward to continuing to collaborate with the
City to effectuate policies and implementation activities
that promote transit oriented communities. If you have any
questions regarding this response, please contact me by
phone at 213-922-2671, by email at
devreview@metro.net, or by mail at the following address:
Metro Development Review
One Gateway Plaza MS 99-22-1
Los Angeles, CA 90012-2952
Sincerely,
Shine Ling, AICP
Manager, Transit Oriented Communities
This comment is the closing of the letter and does not address the ad equacy
of the Draft EIR; therefore, no further response is required.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-44
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
Attachments and links:
• Adjacent Development Handbook:
https://www.metro.net/projects/devreview/
A5-15 Attachment: Metro Adjacent Development Handbook, May
2018
The attachment is provided in support of comment A5-4, addressed above.
A6 SANITATION DISTRICTS OF LOS ANGELES COUNTY
A6-1 October 31, 2019
Ref. DOC 5311089
Ms. Grace S. Lee, Senior Planner
Planning Division
City of Diamond Bar
21810 Copley Drive Diamond Bar, CA 91765
Dear Ms. Lee:
DEIR Response to the Diamond Bar
Comprehensive General Plan Update and Climate Action
Plan
The Sanitation Districts of Los Angeles County (Districts)
received a Draft Environmental Impact Report (DEIR) for
the subject project on September 20, 2019. The City of
Diamond Bar (City) is located within the jurisdictional
boundaries of District No. 21. We offer the following
comments:
This comment is the salutation of the letter and does not address the
adequacy of the Draft EIR; therefore, no further response is required.
A6-2 1. Future Development, page 2-26, paragraph one — The
Districts should review individual developments within
the City in order to determine whether or not sufficient
trunk sewer capacity exists to serve each project and if
Districts' facilities will be affected by the project.
Comment acknowledged. Such review would occur on a project-level basis
separate from the programmatic analysis conducted in the Draft EIR for the
General Plan.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-45
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
A6-3 2. Table 2.3-2, page 2-26, Projected Residential Buildout
and Population (2040) — The table lists 3,264 housing
units as future development within the City and breaks
it down to 142 single-family residential units and 3,122
multi-family residential units. The expected average
wastewater flow from 142 single family homes is
36,920 gallons per day (gpd). Depending on the type of
multifamily unit, the expected average wastewater flow
from 3,122 multi-family residential units could range
from 487,032 gpd to 608,790 gpd. For a copy of the
Districts' average wastewater generation factors, go to
www.lacsd.org, Wastewater & Sewer Systems, click on
Will Serve Program, and click on the Table 1, Loadings
for Each Class of Land Use link.
Under Impact 3.13-1, the Draft EIR projects an overall increase in wastewater
flows between 0.25 and 0.88 million gallons per day, or a range of 300,237
gallons per day to 1,056,836 gallons per day. The Sanitation Districts of Los
Angeles County project average wastewater flow from multi-family residential
units and non-residential future development (addressed in comment A6-4)
to range between 887,314 gpd to 1,009,072 gpd. This is within the range
provided in the Draft EIR, which assumes that the General Plan could result in
a wastewater flow increase of up to 16 percent. Impact 3.13 -1 is determined
to be less than significant.
A6-4 3. Table 2.3-3, page 2-26, Projected Residential Buildout
and Population (2040) — The table breaks down non-
residential by square feet listing future development as
607,283 square feet of retail development, 519,892
square feet of office space, removal of 203,001 square
feet of industrial use structure, and 693,409 square feet
within the "other" category. The expected average
wastewater flow for the non-residential future
development is 400,282 gpd, after all scheduled
industrial structures on the project site are demolished.
See response to comment A6-3.
A6-5 4. Impact 3.6-5, page 3.6-32, paragraph four— It should
also be noted that the Districts are empowered by the
California Health and Safety Code to charge a fee for
the privilege of connecting (directly or indirectly) to the
Districts' Sewerage System for increasing the strength
or quantity of wastewater discharged from connected
facilities. This connection fee is a capital facilities fee
that is imposed in an amount sufficient to construct an
incremental expansion of the Sewerage System to
accommodate the proposed project. Payment of a
Comment acknowledged. This information has been added to the Impact 3.6 -
5 analysis in Chapter 4 of the Final EIR.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-46
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
connection fee will be required before this project is
permitted to discharge to the Districts' Sewerage
System.
A6-6 All other information concerning Districts' facilities and
sewerage service contained in the document is current. If
you have any questions, please contact the undersigned at
(562) 908-4288, extension 2717.
Very truly yours,
Adriana Raza
Customer Service Specialist
Facilities Planning Department
Comment acknowledged.
A7 CALIFORNIA GOVERNOR’S OFFICE OF PLANNING AND RESEARCH, STATE CLEARINGHOUSE AND PLANNING UNIT
A7-1 October 31, 2019
Grace Lee
Diamond Bar, City of 21810 Copley Drive
Diamond Bar, CA 91765
Subject: Diamond Bar Comprehensive General Plan Update
and Climate Action Plan SCH#: 2018051066
Dear Grace Lee:
This comment is the salutation of the letter. It does not address the adequacy
of the Draft EIR; therefore, no further response is required.
A7-2 The State Clearinghouse submitted the above named EIR to
selected state agencies for review. The review period
closed on 10/30/2019, and the comments from the
responding agency (ies) is (are) available on the CEQA
database for your retrieval and use. If this comment
package is not in order, please notify the State
Clearinghouse immediately. Please refer to the project's
ten-digit State Clearinghouse number in future
correspondence so that we may respond promptly.
Comment acknowledged.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-47
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
Please note that Section 21104(c) of the California Public
Resources Code states that:
"A responsible or other public agency shall only make
substantive comments regarding those activities involved
in a project which are within an area of expertise of the
agency or which are required to be carried out or approved
by the agency. Those comments shall be supported by
specific documentation."
Check the CEQA database for submitted comments for use
in preparing your final environmental document:
https://ceqanet.opr.ca.gov/2018051066/2. Should you
need more information or clarification of the comments,
we recommend that you contact the commenting agency
directly.
A7-3 This letter acknowledges that you have complied with the
State Clearinghouse review requirements for draft
environmental documents, pursuant to the California
Environmental Quality Act. Please contact the State
Clearinghouse at (916) 445-0613 if you have any questions
regarding the environmental review process.
Comment acknowledged.
A7-4 Sincerely,
Scott Morgan
Director, State Clearinghouse
cc: Resources Agency
This comment is the closing of the letter. It does not address the adequacy of
the Draft EIR; therefore, no further response is required.
Organizations and Individuals
B1-A DR. DOUGLAS BARCON
B1-A-1 Diamond Bar General Plan EIR comment
October 8, 2019
Railroad sound levels were not measured for the program EIR; ambient noise
measurements were conducted for the General Plan Update to characterize
the general ambient noise environment in the Program Area; however, not
for impact assessment in the Program EIR. Accordingly, as discussed on page
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-48
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
Section 3 Transit Noise, Section 3.1 Noise of the 2018
Metrics Transit Noise and Vibration Impact Assessment
Manual by the Federal Transit Administration:
Railroad sound levels were measured using A-weighting
that approximates typical human hearing and reported as
dBA from the Google Earth reported distance from the
railroad tracks with passing locomotives and rail cars to the
receiving location near the intersection of N. Rock River Dr.
and Red Cloud Dr. in Diamond Bar. The actual Sound Level
Exposure (SEL) 50 feet from the source would require
additional information and calculations or measurement at
the source, which is easier than calculations. Note that
Table 3-1 describes a human-perceived 10 dB increase
above the actual measurements between 10 p.m. and 7
a.m. Therefore, a sound level of 60 dBA would be
perceived as 70 dBA, and a 10 dB increase is perceived as a
doubling of sound levels by the human ear.
3.10-25, “specific details on future railway expansions or improvements are
unknown at this time, neither are the specific noise sources that might occur
in conjunction with development of land uses near the railway under the
Proposed Plan. Therefore, railway noise and vibration impacts are discussed
on a qualitative basis (emphasis added). Policies within the General Plan
Update (e.g., PS-P-52) take into consideration the siting of sensitive receptors
near potential noise generators and would limit the exposure of sensitive
receptors to any existing railway noise. Furthermore, the proposed General
Plan Update does not include any railway upgrades or improvement that
would increase train volumes or number of tracks.”
B1-A-2 Section 3.3 Paths of Transit Noise from Source to Receiver
This section states: “Sound paths from source to receiver
are predominantly through the air. Along these paths,
sound reduces with distance due to divergence,
absorption/diffusion, and shielding.” Per Figure 3-3 below,
the approximate attenuation of the generator SEL at 50
feet would decrease by 20 dBA at 800 feet from the source
and this is a logarithmic decrease. Instead of calculating
the attenuation, it is somewhat easier to extrapolate from
Figure 3-3. It is estimated that there is a 30 dBA
attenuation at 2,000 feet from the source. However, when
one considers Figure 3-4 attenuation over soft ground, it is
clear that height above terrain determines attenuation,
and the neighborhoods south of Dry Creek are more than
40 feet above the source and would have negligible sound
level attenuation by the ground. This corresponds
See response to comment B1-A-1 above.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-49
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
reasonably well with trains passing west, northwest, and
north of the receiving location, but not trains passing
further west by the warehouses along Ferrero Parkway in
the City of Industry. Direction of travel is critical in
determining cumulative sound levels.
Figure 3-3 Attenuation Due to Distance (Divergence)
In the section on shielding, it is noted that noise barriers
are one of the most effective means of mitigating noise,
such as a wall. Walls also reflect sound. When the City of
Industry permitted warehouses with flat vertical walls to
be built along Ferrero Parkway near the Union Pacific
Railroad tracks, railroad sound was amplified and reflected
south and southeast into the Diamond Bar neighborhoods
along Sunset Crossing Road and Prospectors Road. The
noise intrudes into homes.
Figure 3-4 Attenuation Due to Soft Ground
Note that the time period when locomotives pass by those
warehouses, sound is further amplified and reflected.
There is no mitigation of that reflected sound. Possible
mitigation could include sound deadening treatment of the
warehouse walls. Further, when buildings are built on the
flat-topped hill south of the railroad tracks, railroad noise
would be reflected to the northwest and north and then
reflected again off the walls of warehouses (in ellipse)
along Ferrero Parkway. Whether phasing of that sound will
amplify or attenuate the railroad noise is unknown.
Sound/noise mitigation is warranted.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-50
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
B1-A-3 When it comes to community annoyance to the noise,
Figure 3-7 describes it well, and no further discussion on
annoyance is warranted.
Figure 3-7 Community Annoyance Due to Noise
See response to comment B1-A-1 above.
B1-A-4 Lastly, none of this means anything without actual data to
assess the situation and how the Diamond Bar 2040
General Plan Environmental Impact Report will address the
situation. Since there is no supporting data, I collected
some from near the intersection of N. Rock River Dr. and
Red Cloud Dr. in Diamond Bar, as specified in the table
below. Note the time of collection, the distance from the
railroad tracks, and the decibel measurements. It should be
possible to estimate the noise levels at distances closer to
the passing trains.
Train Noise @ N. Rock River Dr. and Red Cloud Dr.,
Diamond Bar
Baseline Level < 50 dB A-Weighting 500 Hz – 10 kHz Fast
[Train Noise table]
Measurement Equipment: Realistic Sound Level Meter No:
33-2050
* Note: The very long train on 10/8/2019 also had a
locomotive in the middle and two at the end.
Freight trains have no posted schedule and pass at random
times. During the measurement period, there were no EB
heavy load trains and no braking. Only one very loud horn
was measured (9/16/2019 at 0110), and it was west of the
receiving location and directed west. Levels hover around
See response to comment B1-A-1 above.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-51
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
reported values within 1-2 dB. Where levels are a range,
the upper level is a peak.
Data captured and logged by Douglas Barcon
Submitted by:
Dr. Douglas Barcon
B1-B DR. DOUGLAS BARCON
B1-B-1 Diamond Bar General Plan 2040 and EIR Comment—
Updated
October 9, 2019
The following is based on Section 3 Transit Noise; Section
3.1 Noise Metrics of the 2018 Transit Noise and Vibration
Impact Assessment Manual by the Federal Transit
Administration, which was provided as a reference in
Chapter 3.10 Noise in the EIR and Chapter 7.8 in the 2040
General Plan.
Railroad sound levels were measured using A-weighting
that approximates typical human hearing and reported as
dBA from the Google Earth reported distance from the
railroad tracks with passing locomotives and rail cars to the
receiving location near the intersection of N. Rock River Dr.
and Red Cloud Dr. in Diamond Bar. The actual Sound Lev el
Exposure (SEL) 50 feet from the source would require
additional information and calculations or measurement at
the source, which is easier than calculations. Note that
Table 3-1 describes a human-perceived 10 dB increase
above the actual measurements between 10 p.m. and 7
a.m. Therefore, a sound level of 60 dBA would be
See response to comment B1-A-1 above.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-52
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
perceived as 70 dBA, and a 10 dB increase is perceived as a
doubling of sound levels by the human ear.
B1-B-2 Section 3.3 Paths of Transit Noise from Source to Receiver
This section states: “Sound paths from source to receiver
are predominantly through the air. Along these paths,
sound reduces with distance due to divergence,
absorption/diffusion, and shielding.” Per Figure 3-3 below,
the approximate attenuation of the generator SEL at 50
feet would decrease by 20 dBA at 800 feet from the source
and this is a logarithmic decrease. Instead of calculating
the attenuation, it is somewhat easier to extrapolate from
Figure 3-3. It is estimated that there is a 30 dBA
attenuation at 2,000 feet from the source. However, when
one considers Figure 3-4 attenuation over soft ground, it is
clear that height above terrain determines attenuation,
and the neighborhoods south of Dry Creek are more than
40 feet above the source and would have negligible sound
level attenuation by the ground. This corresponds
reasonably well with trains passing west, northwest, and
north of the receiving location, but not trains passing
further west by the warehouses along Ferrero Parkway in
the City of Industry. Direction of travel is critical in
determining cumulative sound levels.
Figure 3-3 Attenuation Due to Distance (Divergence)
In the section on shielding, it is noted that noise barriers
are one of the most effective means of mitigating noise,
such as a wall. Walls also reflect sound. When the City of
Industry permitted warehouses with flat vertical walls to
be built along Ferrero Parkway near the Union Pacific
railroad tracks, railroad sound was amplified and reflected
south and southeast into the Diamond Bar neighborhoods
See response to comment B1-A-1 above.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-53
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
along Sunset Crossing Road and Prospectors Road. The
noise intrudes into homes.
Figure 3-4 Attenuation Due to Soft Ground
Note that the time period when locomotives pass by those
warehouses, sound is further amplified and reflected.
There is no mitigation of that reflected sound. Possible
mitigation could include sound deadening treatment of the
warehouse walls. Further, when buildings are built on the
flat-topped hill south of the railroad tracks, railroad noise
would be reflected to the northwest and north and then
reflected again off the walls of warehouses (in ellipse)
along Ferrero Parkway. Whether phasing of that sound will
amplify or attenuate the railroad noise is unknown.
Sound/noise mitigation is warranted as addressed in
General Plan 2040 Chapter 7.8; policy PS-P-51 and Chapter
8.0; policy CHS-P-29.
B1-B-3 When it comes to community annoyance to the noise,
Figure 3-7 describes it well, and no further discussion on
annoyance is warranted.
[Figure 3-7 Community Annoyance Due to Noise]
See response to comment B1-A-1 above.
B1-B-4 Lastly, none of this means anything without actual data to
assess the situation and how the Diamond Bar 2040
General Plan Environmental Impact Report will address the
situation. Since there is no supporting data, I collected
some from near the intersection of N. Rock River Dr. and
Red Cloud Dr. in Diamond Bar, as specified in the table
below. Note the time of collection, the distance from the
railroad tracks, and the decibel measurements. It should be
possible to estimate the noise levels at distances closer to
See response to comment B1-A-1 above.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-54
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
the passing trains, such as along Big Falls Drive and
Strongbow Drive.
Train Noise @ N. Rock River Dr. and Red Cloud Dr.,
Diamond Bar
Baseline Level < 50 dB A-Weighting 500 Hz – 10 kHz Fast
[Train Noise table]
Measurement Equipment: Realistic Sound Level Meter No:
33-2050
* Note: The very long train on 10/8/2019 also had a
locomotive in the middle and two at the end. There was a
parallel train parked on the closer track that attenuated
the noise level somewhat.
Freight trains have no posted schedule and pass at random
times. During the measurement period, there were no EB
heavy load trains and no braking. Only one very loud horn
was measured (9/16/2019 at 0110), and it was west of the
receiving location and directed west. Levels hover around
reported values within 1-2 dB. Where levels are a range,
the upper level is a peak.
B1-B-5 As a final point, in Chapter 7.8 of the 2040 General Plan,
Figure 7-11 on page 7-41, the map shows existing noise
contours in 2016 but does not show any railroad noise
contour in the neighborhood bordered by SR 57 on the
east, City of Industry on the west, and the SR 57/SR 60
confluence on the south. The same map is present in
Chapter 3.10 of the EIR as Figure 3.10-2. The sound levels I
measured and noted in the table above show that this
residential area should have a noise contour included on
the map and on the projected 2040 noise contour shown in
Figure 3.10-2 illustrates vehicle traffic noise contours on area roadways based
on vehicle traffic noise levels estimated from vehicle traffic volumes. See
response to comment B1-A-1 above.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
3-55
Table 3-1: Response to Comments Matrix
Comment ID Comment Response
Figure 7-12 on page 7-42 of the General Plan and in Figure
3.10-2 (or a revision) in the EIR. I will postulate that the
railroad noise levels will decrease to the south of the
highest points on Red Cloud Drive and Prospectors Road as
both roads descend.
Data captured and logged by Douglas Barcon
Submitted by:
Dr. Douglas Barcon
B1-C DR. DOUGLAS BARCON
B1-C-1 Dr. Douglas Barcon
XXXX N. Rock River Dr.
Diamond Bar, CA 91765
Grace Lee
Senior Planner
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
October 29, 2019
Dear Grace,
This comment is the salutation of the letter. It does not address the adequacy
of the Draft EIR; therefore, no further response is required.
B1-C-2 Please add this additional information to my previous
comment on railroad noise for the draft EIR.
Since I submitted my comment on the subject of railroad
noise in Chapter 3.10 Noise in the EIR and Chapter 7.8 in
the 2040 General Plan, I was able to measure the sound
levels of an additional Union Pacific freight train early
Comment acknowledged. See response to comment B1-A-1 above.
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Chapter 3: Responses to Comments
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Comment ID Comment Response
morning on October 24, 2019. This was one of the trains
where the locomotive horn was excessively loud and
measured 82 dBA 2200 - 2500 feet from the source
locomotive, which was facing west away from the homes in
Diamond Bar in the area around N. Rock River Dr. and Red
Cloud Dr. It was the loudest train horn I was able to
measure. Occasional other trains have a horn sound level
that the human ear can sense is even louder. In
comparison to the 82 dBA sound level, I will estimate the
loudest horn sound level to be in the range of 86 - 88 dBA.
Some of these horns also sound at night when the ambient
sound level is in the 40 dBA range. There are no roads
where the locomotives sound their horns, so a quiet zone
designation could mitigate the horn sounding without
spending millions of dollars modifying intersections. A
quiet zone will not impact the other railroad noises.
[Train Noise table]
Measurement Equipment: Realistic Sound Level Meter No:
33-2050
B1-C-3 Respectfully,
Dr. Douglas Barcon
Data captured and logged by Douglas Barcon
This comment is the closing of the letter. It does not address the adequacy of
the Draft EIR; therefore, no further response is required.
B1-D DR. DOUGLAS BARCON
B1-D-1 Dr. Douglas Barcon
XXXX N. Rock River Dr.
Diamond Bar, CA 91765
Grace Lee
Senior Planner
This comment is the salutation of the letter. It does not address the adequacy
of the Draft EIR; therefore, no further response is required.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
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Comment ID Comment Response
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
October 31, 2019
Re: Draft Environmental Impact Report
Dear Ms. Lee,
B1-D-2 I have been reviewing the draft Environmental Impact
Report and have additional comments on other topics
beyond those I have previously submitted regarding
railroad noise.
In the Executive Summary of the Draft Environmental
Impact Report for the Diamond Bar General Plan 2040 a nd
Climate Action Plan Table ES-4: Summary of Impacts and
Mitigation Measurers in section 3.6 Geology, Soils,
Seismicity, and Paleontology starting on page ES-46 shows
no mitigation measures are necessary for section 3.6-3
Implementation of the Proposed Project and would not
result in significant development located on a geologic unit
or soil that is unstable, or that would become unstable as a
result of the project, and potentially result in on- or off-site
landslide, lateral spreading, subsidence, liquefaction or
collapse. I must question the statement that mitigation is
not necessary. Specifically, I am addressing the mixed -use
area on North Diamond Bar Boulevard between SR-60 and
Sunset Crossing Road. This is the area next to the Diamond
Bar Boulevard exit from the westbound SR-60.
Comment acknowledged. The Draft EIR assumes that development under the
General Plan, including the mixed use area discussed in this comment, could
include development occurring on unstable soil or geologic units such as the
surrounding steep slopes. These potential hazards would be addressed
through the integration of geotechnical information in the planning and
design process for projects in accordance with standard industry practices and
state-provided requirements. Development must be compliant with the
California Building Standards Code Chapters 16 and 18 and Appendix J, as well
as Diamond Bar Municipal Code Chapter 22.22 (Hillside Management),
Chapter 22.48 (Development Review), and Section 15.00.320. Notably,
Section 1803.8.1 states that work requiring a building or grading permit is not
allowed in an area that the City Engineer determines to be subject to hazard
from landslide, settlement, or slippage. Therefore, approval of any
development project in this area would be contingent on its ability to comply
with these regulations. As stated, multiple General Plan policies, including
policy LU-P-56, address potential impacts associated with development in this
area.
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Chapter 3: Responses to Comments
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The area in question is shown in the excerpt Figure 3.6-1:
Steep Slopes below.
[Figure 3.6-1: Steep Slopes]
Note the green areas (steep slopes) beside the Diamond
Bar Boulevard off-ramp (red-brown) from the WB SR-60
and along the right side of Diamond Bar Boulevard (gray
line parallel to SR-57) toward Sunset Crossing Road. There
are homes at the top of those slopes. The beige area at the
off-ramp and extending to Sunset Crossing Road is flat land
sandwiched between Diamond Bar Boulevard and the
steep slopes in green. This flat land has been incorporated
into the North Diamond Bar Boulevard mixed-use area.
Civil engineers have previously stated that the slopes can
be damaged, and their stability compromised by cutting
into them to develop the narrow ribbon of flat land to the
right of Diamond Bar Boulevard north of the off-ramp.
Further, building a driveway adjacent to a busy freeway
off-ramp is a safety issue that can lead to collisions and
injuries. The flat land should remain as open space that
could be landscaped, providing weeds on the hillsides can
be removed to mitigate fire danger to the houses above.
Developers should not be permitted to develop a property
that jeopardizes the environment and creates a risk to
others. Such development of this property is also
addressed in section 3.6-4, which also states no mitigation
measures are required. The direct risk is a possible collapse
of the hillside by carving into it a non-specified distance to
enlarge the flat pad. This area should be removed from the
mixed-use designation in the General Plan Update and left
as open space, perhaps with landscaping. Policies LU-P-55,
LU-P-56, PS-G-1, and PS-P-2 address some of this.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
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Comment ID Comment Response
B1-D-3 The colors shown in Figure 3.8-1: FEMA Flood Insurance
Rate Map on page 3.8-5 are incorrect. Diamond Bar is
shown in white on the map, but the map key shows it is
cream-colored. The key currently indicates that white is a
county boundary.
Comment acknowledged. The map key for Figure 3.8-1 indicates that the
black dashed line shows the City of Diamond Bar boundary, while the light
gray dashed line shows the County Boundary. Figure 3. The colors shown on
the map in Figure 3.8-1 are correct. The map key in Figure 3.8-1 has been
revised in Chapter 4 of the Final EIR to remove the cream-colored fill of the
City of Diamond Bar key.
B1-D-4 In Chapter 3.9: Land Use, Population, and Housing, the
2040 projections on page 3.9-7 state that Diamond Bar’s
population will increase to 66,685 residents from the
current 57,853 residents or an increase of 8,832 residents
according to SCAG. At a population of 3.16 persons per
occupied unit, that equates to 2,795 new residential units.
Where are these units going to be built, and what is their
impact on circulation, land use, and public safety? Transit-
oriented-development and mixed-use will accommodate
some of these units. If the city intends to preserve open
space, it may not be possible with the SCAG projected
growth.
The General Plan would concentrate residential growth in the proposed
mixed-use districts (Town Center Mixed Use, Neighborhood Mixed Use,
Transit Oriented Mixed Use, and Community Core). The Draft EIR includes
analysis of circulation, land use, and public safety impacts based on this land
use pattern. Buildout of the General Plan assumes standard growth rates in
the rest of the City of Diamond Bar and does not propose new development
in existing residential neighborhoods. The General Plan does not propose
development of open space and includes multiple policies and land use
designations aimed at preserving open space.
B1-D-5 Table 3.12-11: Commuter Mode Split in Diamond Bar and
Surrounding Areas on page 3.12-4 indicates that Diamond
Bar currently had 0.7% of the population commuting by
bicycle and walking compared to 3.6% in Los Angeles
County. Figure 3.12-2: Proposed Bicycle Network on page
3.12-11 is a map that shows the proposed bicycle network
in Diamond Bar. The location of Diamond Bar to jobs and
the hilly area probably explains the variation. The
likelihood of bicycling and walking increasing by even 2
percent over the next 20 years is questionable regardless
of any state mandates. The state cannot dictate how a
person commutes or travels.
Comment acknowledged. The City acknowledges existing barriers to bicycling
and walking that result in this variation. The General Plan proposes multip le
policies aimed at prioritizing bicycle and pedestrian infrastructure and
reducing risk and injury to bicyclists and pedestrians. Development of new
mixed-use areas and construction of protected bike lanes would further
encourage residents to commute via bicycle and walking.
B1-D-6 The draft general plan has proposed bike lanes where bike
travel is difficult, such as up Sunset Crossing Road to
Golden Springs Drive and up Gold Rush Drive from
Diamond Bar Boulevard to the top of the hill at Leyland.
Comment acknowledged. See response to comment B1-D-5 above. This
comment discusses bicycle and circulation policies proposed in the General
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
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Comment ID Comment Response
Traffic mitigation is also planned for Gold Rush Drive.
Bicycle riders are at risk of injury on either of these routes,
and the likelihood of a bicycle rider using such bike lanes is
minimal. Type IV bikeways are impractical on Sunset
Crossing Road or Gold Rush Drive, so any bicyclists are not
protected from motor vehicle traffic. It is the same issue
along Prospectors Road because cars are parked along the
sides of the road where a bike lane also exists. It is not
practical to eliminate street parking to accommodate
bicycles. Various policies in Circulation address bicycles.
Providing expanded bike lanes is reasonable, but
expanding bike lanes into areas where they are impractical
and can result in increased risk and injury to the bicycle
rider should be reconsidered. The concept of bicycle riders
switching to motorized bicycles has DMV licensing issues
and additional safety issues and is not an answer to riding a
bicycle up a steep roadway. There are lofty goals in the
Circulation policies that are not practical regardless of
whether the wording uses encourage instead of another
word. Circulation policy CR-P-4 cited on page 3.12-33 will
have minimal impact on the few pedestrians who walk
from Temple Avenue to Sunset Crossing Road, but it will
have a significant impact on vehicular traffic. The
southbound side of Diamond Bar Boulevard to SR -60 is
bordered by SR-57 to the right; there is nothing built on
that side of the street. Traffic calming serves no purpose on
that side of the street, but it will impact a bike lane on that
side of the street if there are bump-outs placed that
require a bicycle rider to navigate around and move them
closer to vehicular traffic.
Plan but does not address the adequacy of the Draft EIR; therefore, no further
response is required.
B1-D-7 Respectfully,
Dr. Douglas Barcon
This comment is the closing of the letter. It does not address the adequacy of
the Draft EIR; therefore, no further response is required.
B2 HILLS FOR EVERYONE
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
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Comment ID Comment Response
B2-1 October 29, 2019
Submitted via email to: GLee@DiamondBarCA.Gov
Grace Lee, Senior Planner
City of Diamond Bar
21810 Copley Drive
Diamond Bar California 91765
RE: Comments on the Diamond Bar General Plan Update
and EIR
Dear Ms. Lee:
This comment is the salutation of the letter. It does not address the adequacy
of the Draft EIR; therefore, no further response is required.
B2-2 I’m writing on behalf of Hills For Everyone (HFE), to provide
comments on the City of Diamond Bar’s (City) General Plan
Update (GPU). HFE is a non-profit organization that strives
to protect, preserve, and restore the environmental
resources and natural environs of the Puente-Chino Hills
and surrounding areas for the enjoyment of current and
succeeding generations. We are closely following the City’s
GPU as there are natural lands within the city proper and
its sphere of influence.
Comment acknowledged.
B2-3 Public Process Comments
This letter serves as a follow up to our comment letter
from July 6, 2018 and focuses on the policies in the new
General Plan. It is our understanding from the Diamond Bar
General Plan Update website
(http://www.diamondbargp.com/) that the documents
(Environmental Impact Report, GPU, and Climate Action
Plan) were released for a 45 day review period beginning
September 16, 2019 and set to end October 31, 2019.
Comment acknowledged. This comment discusses the public review process
and does not address the adequacy of the Draft EIR; therefore, no further
response is required.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 3: Responses to Comments
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Comment ID Comment Response
In our 2018 letter, we specifically requested notification
per Public Resources Code §21092.2 to receive updates
about the project. However, it appears that two meetings
(listed as Study Sessions on the website) from September
25 and October 8, 2019 literally changed the documents
we were reviewing during the public comment period.
These Study Sessions and document changes should have
occurred prior to the document’s release for public review.
We have accessed the changes published on the website,
but must relay our dismay at the public process. As a
governmental entity, as public officials, and as planners
you should know better.
We do not understand why after release for public review,
these documents were then significantly modified. This is
exactly the type of poor public process that confuses the
public, limits engagement, clouds transparency, and leads
to distrust toward government. We request that you
officially re-notice and recirculate the entire suite of
documents (with the updates from September and October
2019 included) for a new 45-day review period.
B2-4 Further, it appears that most of the modifications made
essentially eliminate any enforceability of the General Plan
policies. The General Plan needs to be the document t hat
sets the ground rules for the future of the city. When you
change “require” to “encourage,” there is too much
flexibility in the policy. Using the flexible policy language
implies interest in the policy, but no real commitment to it
or its enforcement. Flexible policy language does not carry
the force of law.
Comment acknowledged. Revisions to General Plan policy language were
carefully made in order to reflect the City’s capabilities and provide consistent
language throughout the document without diminishing the City’s
commitment to upholding the proposed policies throughout implementation
of the General Plan. Revisions to the policy language do not change the intent
of these policies or significantly reduce their applicability in the Draft EIR
impact analysis and resulting conclusions. These modifications do not result in
any new significant impacts and the Draft EIR therefore remains adequate.
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Chapter 3: Responses to Comments
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According to the General Plan Guidelines developed by the
comprehensive state planning agency, the Office of
Planning and Research (OPR), “It is better to adopt no
policy than to adopt a policy with no backbone.” (Office of
Planning and Research. “General Plan Guidelines.” 15.) In
addition, for a policy to be counted towards “mitigating of
a plan’s impacts,” it must be expressed as mandatory. We
urge you to reconsider the edits made in September and
October 2019 and require enforceability through stronger
policy language.
B2-5 General Plan Policy Comments
Hills For Everyone provided a suite of topics to consider
during the Notice of Preparation of an Environmental
Impact Report for the GPU. These bulleted items relay
what we noticed from the draft GPU.
• We support the focus of infill and preservation of open
space (LU-G-2 and -4) and we support the plan’s
attempt to limit impacts to existing residential areas by
ensuring there are compatible adjacent land uses (LU-P-
8 and -9).1 LU-P-10 is a good goal (incentivize affordable
housing) and should help (if implemented) meet the
new Regional Housing Needs Assessment numbers for
Diamond Bar.
1The policies have since been modified to a less
enforceable policy; we instead support the original
language.
Comment acknowledged. Policies LU-P-8 and LU-P-9 as revised ensure that
new development is compatible with existing adjacent land uses. See
response to comment B2-4 above.
B2-6 • The inclusion of density and massing in several policies
and setting a maximum dwelling unit/acre for the
Transit-Oriented Mixed Use designation is appreciated.
This should help stable residential neighborhoods
understand what may or may not be possible to build
next to them.
Comment acknowledged.
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B2-7 • Ensuring existing vistas of significant hillside features
are preserved will help maintain Diamond Bar’s
character. This sets a good tone for the community too.
Comment acknowledged.
B2-8 • In LU-P-2, we appreciate your inclusion of sensitive
species and wildlife corridors. Further, RC-P-112 helps
maintain more natural characteristics of wildland areas
especially with the inclusion of wildlife movement
linkages, reduced night lighting, and vegetative
buffering. These policies should help the Puente-Chino
Hills Wildlife Corridor lands function and maintain their
integrity across multiple counties and multiple cities.
2Ibid.
Comment acknowledged. The City looks forward to working with Hills for
Everyone in securing and maintaining the Puente-Chino Hills Wildlife
Movement Corridor.
B2-9 • We appreciate the inclusion of language to not only
acknowledge Significant Ecological Areas, but also to
maintain, protect and preserve those biologically
significant lands (RC-G-4 and RC-P-8).3
Comment acknowledged. As stated in policy RC-P-8, the City looks forward to
supporting the efforts of neighboring jurisdictions and conservation
organizations, including Hills For Everyone, to protect biologically significant
lands such as areas identified as Significant Ecological Areas.
B2-10 Missed Opportunities
We noticed that there were no opportunities for
streamlined permitting for land uses like mixed use. This
could help Diamond Bar residents reduce their single
occupancy vehicle use and reduce greenhouse gas
emissions. We encourage Diamond Bar to consider adding
streamlined/incentivized permitting for mixed use and
transit-oriented projects.
Comment acknowledged. The General Plan proposes four new areas of
mixed-use development and includes multiple policies regarding development
in mixed-use areas. This comment does not address the adequacy of the Draft
EIR; therefore, no further response is required.
B2-11 With new legislation regarding Accessory Dwelling Units
(ADUs), Diamond Bar missed a chance to memorialize
policies related to ADUs. This should be considered and
incorporated so that it is vertically consistent with the
zoning code (§22.42.120).
Comment acknowledged. This comment does not address the adequacy of
the Draft EIR; therefore, no further response is required.
B2-12 We again recommend defining what a “major project” is in
this document (either by the number of units, project siz e,
acreage, or amount of grading). For example, this applies
Comment acknowledged. Policy LU-P-4 actually states: “Monitor and evaluate
potential impacts of proposed adjacent, local, and regional developments to
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Chapter 3: Responses to Comments
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Comment ID Comment Response
to LU-P-4: “Monitor and evaluate potential impacts of
major proposed adjacent, local, and regional
developments...” What exactly triggers this “monitoring
and evaluating?”
We recommend, again, setting consistent guidelines that
link density, massing, and design. It would make the
document more consistent throughout and set the tone for
the City.
anticipate and require mitigation to the greatest extent feasible to reduce
land use, circulation, and economic impacts on Diamond Bar.”
This comment does not address the adequacy of the adequacy of the Draft
EIR; therefore, no further response is required.
B2-13 Errors in the Document
We again remind you that the area labeled Firestone Scout
Reservation on several figures in the document are not
accurate. Firestone Scout Reservation was the former
name, but that land has been owned by the City of Industry
since 2001. This naming error should be corrected on
Figures 1-1, 5-1, 6-1, 6-2, 6-3, and 7-9, and Table 5.2 (in
two places). Additionally, this land is not designated
parks/open space. We recommend labeling this land as
Significant Ecological Area instead.
Comment acknowledged. This comment proposes changes to the General
Plan figures and tables and does not address the adequacy of analysis in the
Draft EIR; therefore, no further response is required.
B2-14 Thank you for the opportunity to provide substantive
feedback on the GPU. To reiterate, we urge the City to re-
notice and recirculate the documents. Should you have any
questions, I can be reached at 714-996-0502.
Comment acknowledged.
B2-15 Sincerely,
Claire Schlotterbeck
Executive Director
This comment is the closing of the letter. It does not address the adequacy of
the Draft EIR; therefore, no further response is required.
B3 HAMILTON BIOLOGICAL
B3-1 October 31, 2019
Mr. Greg Gubman
Director of Community Development
This comment is the salutation of the letter. It does not address the adequacy
of the Draft EIR; therefore, no further response is required.
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Chapter 3: Responses to Comments
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Comment ID Comment Response
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
SUBJECT: COMMENTS ON DRAFT EIR
DIAMOND BAR GENERAL PLAN UPDATE
Dear Mr. Gubman,
B3-2 Working on behalf of a consortium of Diamond Bar
residents, including Diamond Bar Preservation Foundation,
Responsible Land Use, and the Diamond Bar/Pomona
Valley Sierra Club Task Force, Hamilton Biological, Inc.,
(hereafter “Hamilton Biological”) provides these comments
on a proposed update to the City of Diamond Bar
(hereafter the “City”) General Plan. My comments focus on
Chapter 3.3 (Biological Resources) and Chapter 5.0
(Conservation Element).
As described in the attached Curriculum Vitae, Hamilton
Biological specializes in third-party review of technical
biological reports and CEQA documentation. Relevant to
this project, Hamilton Biological prepared the following
documents that were submitted to the City in February
2019:
• Biological Resources Report, City of Diamond Bar.
Report dated February 25, 2019, prepared for a
consortium of Diamond Bar residents and submitted to
Mr. Greg Gubman, Director of Community
Development, City of Diamond Bar. 35 pp. plus
Appendix A (Methods and Technical Information).
• Cover letter dated February 21, 2019, accompanying
the above-referenced Biological Resources Report,
submitted to Mr. Greg Gubman, Director of Community
Comment acknowledged.
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Development, City of Diamond Bar. 10 pp. plus
Curriculum Vitae. [copy attached]
This letter addresses Chapter 3.3 (Biological Resources) and
Chapter 5.0 (Conservation Element).
B3-3 EIR’S CONTENT AND ANALYSES STRAY FROM THE STATED
METHODS
The DEIR does not identify the biologist(s) responsible for
preparing its analyses, but Steve Nelson of ESA has served
as the City’s biological consultant during public meetings
and Chapter 7.1 lists him as a preparer of the DEIR, so it
appears that Mr. Nelson and ESA was responsible for the
analyses contained in Chapter 3.3 (Biological Resources)
and Chapter 5.0 (Conservation Element).
Page 3-3.1 of the DEIR states:
The assessment of sensitive habitats and watersheds in this
EIR is based on literature review and the Hamilton
Biological Resources Report, as discussed below, rather
than on the Existing Conditions Report.
If the EIR’s assessment of these core issues were truly
based upon the Hamilton Biological Resources Report, with
certain modifications based upon the EIR preparer’s review
of the relevant literature, my comments on the DEIR would
be few and mostly complimentary. Such is not the case.
As a start, the DEIR fails to incorporate numerous records
of special-status species documented in the City limits
during recent years. For example, Dan Cooper’s records of
California Gnatcatchers at Pantera Park was available on
the California Natural Diversity Database (CNDDB) as of
February 27, 2019, and on eBird (http://ebird.org) in 2017.
Steve Nelson was ESA’s lead biologist for the EIR assessment. To the extent it
was appropriate to incorporate the information provided in the Hamilton
Biological Resources Report as part of a General Plan Update EIR, it was. In
some cases, however, the intent of incorporating such information was
addressed in a manner that better served the purpose of a General Plan
program. For example, the comment criticizes the omission of specific
records of special-status species. Rather, the EIR includes Tables 3.3-3 and
Table 3.3-4 which summarizes such special-status species of plants and
wildlife, their special-status character, their preferred habitat, and their
presence or the potential for occurrence in the study area. In addition, Table
3.3-6 indicates the habitats in which federal and state-listed species have
been observed or could occur in the study area. In the context of a General
Plan that is intended to guide the city’s future development, this approach
was felt to be much more effective in identifying areas/habitats of special
concern. Moreover, specific sites where special-status species have been
observed are likely to change over time. As such, the presentation of data as
suggested in the comment could lead to the interpretation that the existing
sightings and records are the only place where special-status species may
occur.
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Records of several Red-diamond Rattlesnakes at
Summitridge Park from 2014 to 2017 were available on the
CNDDB on March 22, 2019. The EIR preparer claims to have
reviewed both the CNDDB and eBird in “May 2019,” yet
these records are missing from Figure 5.4 in the DEIR
(Special Status Animals). The CNDDB has not yet entered
my observations of special-status birds from January 2019,
but they have been available on eBird since that month.
My cover letter to the City dated February 21, 2019,
provided specific following links to eBird checklists that
report/document the relevant following records, including
UTM coordinates:
• California Gnatcatchers and Cactus Wrens — Steep
Canyon near Diamond Bar Boulevard, 1/4/19:
https://ebird.org/view/checklist/S51322203
• Cactus Wrens — Pantera Park, 1/4/19:
https://ebird.org/view/checklist/S51324514
• California Gnatcatcher and Cactus Wrens — vic.
northwestern part of Tres Hermanos Ranch, 1/4/19:
https://ebird.org/view/checklist/S51324625
• California Gnatcatchers — vic. Diamond Ranch High
School, 1/4/19:
https://ebird.org/view/checklist/S51324760
• Northern Harrier — Tres Hermanos Ranch north of
Grand Avenue, 1/4/19:
https://ebird.org/view/checklist/S51324857
• California Gnatcatchers and Cactus Wrens, plus Golden
Eagle seen soaring over Tres Hermanos Ranch —
Summitridge Trail, 1/8/19:
https://ebird.org/checklist/S51487531
B3-4 [Occurrence Report, California Department of Fish and
Wildlife, California Natural Diversity Database: coastal
See response to B3-3 above.
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California gnatcatcher. Report dated September 29, 2019.
Report printed Thursday, October 17, 2019.]
B3-5 [Occurrence Report, California Department of Fish and
Wildlife, California Natural Diversity Database: red-
diamond rattlesnake. Report dated September 29, 2019.
Report printed Thursday, October 17, 2019.]
See response to B3-3 above.
B3-6 Photos from my eBird reports, showing special-status
species recorded in the City:
Photo 1. California Gnatcatcher, Diamond Ranch High
School, January 4, 2019.
UTM 428495 3764853
Photo: Robert A. Hamilton
Photo 2. California Gnatcatcher, Summitridge Park, January
8, 2019.
UTM 425808 3762536
Photo: Robert A. Hamilton
Photo 3. Cactus Wren pair, Summitridge Park, January 8,
2019.
UTM 425811 3762529
Photo: Robert A. Hamilton
See response to B3-3 above.
B3-7 Chapter 6 of the DEIR shows that the EIR preparer’s
“literature review” for biological resources includes only
seven entries:
Beier, P. and R.H. Barrett. 1993. The cougar in the Santa
Ana Mountain Range, California. Final report. Orange
County Cooperative Mountain Lion Study, Department of
Chapter 6 of the DEIR only included the literature cited in the assessment. It
did not include materials used as general references, including but not
necessarily limited to:
• American Ornithologists’ Union (AOU). 2018. Checklist of North
American and Middle American Birds. AOU website
http://checklist.aou.org/taxa/.
• Baldwin, et al. 2012. Jepson Manual: Vascular Plants of California;
Second Edition. University of California Press.
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Forestry and Resource Management, University of
California, Berkeley, USA.
Beier, P.1993. Determining minimum habitat areas and
habitat corridors for cougars. Conservation Biology 7:94
108. California Native Plant Society. 2019. Electronic
Inventory of Rare and Endangered Vascular Plants of
California. http://www.rareplants.cnps.org/. Accessed May
2019.
California Department of Fish and Wildlife. 2019. California
Natural Diversity Database: Rarefind.
https://www.wildlife.ca.gov/Data/CNDDB. Accessed May
2019.
eBird. 2019. Explore Species. https://ebird.org/explore.
Accessed May 2019.
Hamilton Biological, Inc. 2019. Biological Resources Report
for the City of Diamond Bar.
Los Angeles Audubon. 2009. Los Angeles County’s Sensitive
Bird Species. http://planning.lacounty.gov/site/sea/wp-
content/uploads/2018/08/LA-Countys-Sensitive-Bird-
Species.pdf. Accessed May 2019.
As demonstrated previously, the EIR preparer’s reviews of
the CNDDB and eBird, which reportedly took place in “May
2019,” failed to turn up documented records of several
special-status species from within the City limits.
Furthermore, this short list of basic references is grossly
inadequate for a biological assessment and analysis
covering the City of Diamond Bar and its extensive Sp here
of Influence in Tonner Canyon. Page 3.3-2 of the DEIR
states:
However, it should be noted that site specific assessments
and focused surveys have been conducted in areas of
future development anticipated by the Proposed Project
• Calflora. 2018. Information on California plants for education,
research and conservation [web application]. Berkeley, California:
The Calflora Database [a non-profit organization]. Available:
http://www.calflora.org/ (Accessed: April 26, 2018).
• California Herps (CalHerps). 2018. A Guide to the Amphibians and
Reptiles of California. Accessed online at
http://www.californiaherps.com/.
• California Department of Fish and Wildlife (CDFW). 2018a. California
Natural Diversity Database (CNDDB) Rarefind 5. Electronic database,
Sacramento, California. Accessed at:
https://www.wildlife.ca.gov/Data/CNDDB/Maps-and-Data. Accessed
on April 6 and December 12, 2018.
• CDFW. 2018b. Protocols for Surveying and Evaluating Impacts to
Special Status Native Plant Populations and Natural Communities.
State of California Natural Resources Agency. March 20, 2018.
• CDFW. 2018c. California Natural Community List. Vegetation
Classification and Mapping Program. October 15, 2018.
https://www.wildlife.ca.gov/Data/VegCAMP/Natural-
Communities#natural%20communities%20lists.
• California Native Plant Society (CNPS). 2018. Inventory of Rare and
Endangered Plants (online edition, v8-01a). Sacramento, CA.
http://www.rareplants.cnps.org/. Accessed on April 6 and December
12, 2018.
• Cowardin, L.M., V. Carter, F.C. Golet, E.T. LaRoe. 1979. Classification
of Wetlands and Deepwater Habitats of the United States. U. S.
Department of the Interior, Fish and Wildlife Service, Washington,
D.C.
• Crother, B. 2018. Checklist of the Standard English and Scientific
Names of Amphibians and Reptiles. Society for the Study of
Amphibians and Reptiles. Accessed at
https://ssarherps.org/publications/north-american-checklist/.
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where the occurrence of special status species do exist.
The Diamond Bar Village Specific Plan, South Pointe West
Specific Plan, and Site D Specific Plan previously completed
assessments of biological resources located within their
planning areas. The City of Industry has completed multiple
site specific assessments of Tonner Canyon.
None of these reports is cited in the DEIR, and no relevant
biological information appears to have been obtained from
them, or from any other biological assessments and
analyses prepared for projects in and around the City of
Diamond Bar. Numerous relevant citations from the
scientific literature on habitat loss, habitat degradation,
and habitat fragmentation and their effects on plant and
wildlife populations, are also missing.
• Environmental Laboratory. 1987. U.S. Army Corps of Engineers
Wetland Delineation Manual. Prepared for the U.S. Army Corps of
Engineers.
• Kaufman, Kenn, Nora Bowers, Rick Bowers. 2004. Field Guide to
Mammals of North America. New York, New York: Houghton Mifflin
Company.
• Lichvar, R.W., D.L. Banks, W.N. Kirchner, and N.C. Melvin. 2016. Arid
West 2016 Regional Wetland Plant List. Phytoneuron 2016-30: 1-17.
Published 28 April 2016.
• Sawyer, J. O., T. Keeler-Wolf, and J. M. Evens. 2009. A Manual of
California Vegetation, Second Edition. California Native Plant Society,
Sacramento, CA.
• South Coast Wildlands. 2008. South Coast Missing Linkages: A
Wildland Network for the South Coast Ecoregion.
http://www.scwildlands.org/reports/SCMLRegionalReport.pdf.
March 2008.
• Stebbins, R. C. 2003. A Field Guide to Western Reptiles and
Amphibians Third Edition. Boston: Houghton-Mifflin.
• USACE. 2008. A Field Guide to the Identification of the Ordinary High
Water Mark (OHWM) in the Arid West Region of the Western United
States. A Delineation Manual. August 2008.
http://www.dtic.mil/dtic/tr/fulltext/u2/ a486603.pdf.
• USFWS. 2018b. Critical Habitat Portal. Accessible online at:
http://ecos.fws.gov/crithab/.
• USFWS. 2018c. National Wetland Inventory.
https://www.fws.gov/wetlands/data/Mapper.html.
• United States Geological Survey (USGS). Yorba Linda and San Dimas,
California. 7.5-minute topographic quadrangle maps.
B3-7 GENERAL PLAN SHOULD FOCUS ON GUIDING CEQA
REVIEW PROCESS
Whereas the comment indicates the Hamilton Biological Resource Report was
geared toward assisting the city in its on-going role as a CEQA lead agency,
the cover letter subject is stated as “Biological Resources Report for Open
Space & Conservation Element Diamond Bar General Plan Update” and is
organized accordingly. While the information that was incorporated in the
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The Hamilton Biological Resources Report is intentionally
geared toward making connections between resources and
conservation policies, with the ultimate goal of assisting
the City in its ongoing role as a CEQA lead agency. Note
that the Hamilton Biological Resources Report did not map
the plant communities within the area covered in the
General Plan. Instead, my report:
1. Mapped the areas of natural open space in the
City and its Sphere of Influence.
2. Described the general types of plant communities
found in each area.
3. Identified the methods that should be used to
implement project-level investigations (e.g.,
characterizing plant communities, conducting
focused surveys for special-status species).
4. Developed reasonable policies designed to
effectively protect any biologically sensitive
resources that might be found in the project-level
investigations.
The report’s final section, Natural Resource Conservation
Policies, specifically builds upon existing policies from the
current draft version of the General Plan update, adapting
them to facilitate efforts to identify and protect areas of
particular ecological concern in the City and its Sphere of
Influence.
Given the DEIR’s explicit statement that the “assessment of
sensitive habitats and watersheds in this EIR is based on
literature review and the Hamilton Biological Resources
Report,” the City should adopt Hamilton Biological’s
rational, factual, defensible approach to these issues.
EIR assessment was helpful and appreciated the focus of the report was not
targeted on the EIR assessment. In fact, the city’s General Plan does not
include an Open Space & Conservation Element by its choice, but instead
includes this information in the extensive Resource Conservation chapter. It is
the City’s option and responsibility to base its adoption of policies on the
bases of more than a single perspective.
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B3-9 MIS-MAPPING OF PLANT COMMUNITIES
Figure 3.3-1 on page 3-3-10 of the DEIR maps some very
small areas in the northeastern part of the City as “Coast
Live Oak Woodland,” and some extensive areas in Tonner
Canyon (areas very unlikely to be developed in the future)
as “California Walnut Woodland/Coast Live Oak
Woodland.” But, as in the Existing Conditions Report (that
as explicitly not used to for the EIR’s assessment of
sensitive habitats and watersheds), nearly all woodlands
within City limits are mapped as “California Walnut
Woodland.” As stated on page 3.3-2 of the DEIR:
ESA (Environmental Science Associates) biologists
conducted a reconnaissance survey on August 25, 2016, to
develop a broad-scale classification of the vegetation
communities within the Planning Area. Prior to field
surveys, a desktop analysis was conducted to obtain
contextual information relevant to the area. Mapping and
habitat types were compiled based on a desktop analysis of
2015 aerial imagery, as well as the reconnaissance survey
to confirm natural communities as interpreted from aerial
imagery (Google Maps 2015) and the reconnaissance-
level inspection.
A single survey day is clearly inadequate to accurately map
all of the plant communities in the City of Diamond Bar and
its Sphere of Influence, even at a broad scale.
I addressed the issue of erroneous mapping of oak
resources on page 5 of my letter to the City dated February
21, 2019:
Natural Communities Mis-Mapped
It is acknowledged that the distinction and mapping of oak versus oak/walnut
versus walnut woodlands is an on-going issue in the General Plan Update
process. On the one hand, the EIR assessment states:
“Although considered distinct vegetation alliances by Sawyer et. al., there is a
high degree of intermixing between the oak woodland alliance and walnut
woodland alliance. For the purpose of this assessment it was not practical to
distinguish between the two over the mosaic these alliances form in the City
and SOI. However, as needed for the City’s environmental review process,
this may be needed at the site-specific level.”
and,
“there can be misinterpretations of the alliance type when viewed from a
distance or in aerial photography, particularly in the winter when the winter -
deciduous California walnut has no leaves. For this reason, the mapping of
these alliances in Figure 3.3-1 should be viewed as being subject to site-
specific investigations.” It should also be noted that both the oak and walnut
natural communities are considered sensitive to the same degree in the
assessment. However, there remains controversy.
In support of the commenter’s position, maps provided in the Los Angeles
County Oak Woodlands Conservation Management Plan Guide are cited as
showing extensive areas of oak woodlands throughout the study area. The
reader should note, however, that the document states the following caveat
for its use:
“This figure includes a 200 foot (sic) buffer around the woodland interface
zone and potential oak woodland zone, as mapped by CALVEG. Due to the
scale of the CALVEG layers used to generate this map, it is possible that not all
parcels located within the illustrated oak woodlands areas actually support
existing oak trees. Individual parcels will be examined further whenever a
permit request or application for voluntary oak woodland conserved is
reviewed.” Thus, the CALVEG are an over exaggeration of the actual extent of
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Part of my study involved identifying the main natural
communities occurring in natural open space areas
scattered throughout the Study Area. As shown in Figure 7,
below, oak woodlands occur extensively throughout the
undeveloped parts of the Study Area:
Figure 7. Excerpt from Figure 3 in the Los Angeles County
Oak Woodlands Conservation Management Plan Guide
(http://planning.lacounty.gov/assets/upl/project/oakwood
lands_conservation-management-plan-guide.pdf) showing
the southeastern part of the County and accurately
depicting extensive oak woodlands in the Study Area. Beige
polygons represent oak woodlands.
During my own field work I have observed that throughout
the Study Area, oak woodlands cover much larger areas
than do walnut woodlands. The Dyett & Bhatia Report
provides no explanation for the contrary findings depicted
in their Figure 2-1 [which has been recycled as Figure 3-3.1
in the DEIR]. Dyett & Bhatia’s claim of 1,189.9 acres of
California Walnut Woodland in the Study Area, compared
with only 206.9 acres of Coast Live Oak Woodland and
585.4 acres of walnut/oak woodlands, represents an error
that grossly under-represents the extent of oak woodlands
in the Study Area. If the City determines that large-scale
mapping of natural communities is needed for the General
Plan update, the mapping provided in the Dyett & Bhatia
report must be completely revised and carefully field-
checked for accuracy.
Especially in light of the recent unpermitted removal of
numerous large oaks in Diamond Bar
(https://www.diamondbarca.gov/724/Millennium-
Development-TR-53430), the City should be cognizant of
oak woodlands in the Puente Hills; and walnut woodland (which has its largest
distribution in the Puente Hills, and cannot be overlooked. Further, CALVEG’s
guidance to examine individual parcels is the precise approach the EIR
assessment includes. As such there does not appear to be a controversy on
how this issue should be approached. Notwithstanding, the EIR assessment
added an additional layer of analysis to focus this analysis.
According to the body of knowledge on the subject north and east-facing
slopes typically hold greater moisture than south and west-facing slopes, at
least in the southern California region. As a result, coast live oak trees
dominate woodlands found on north and east-facing slopes and walnut trees
typically dominate woodlands found on south and west-facing slopes. By
using a slope aspect direction between 315 to 135 degrees to identify north
and east-facing slopes and a slope aspect between 135 to 315 degrees to
identify south and west-facing slopes on a GIS platform a refined means of
identifying woodland types in the study area may be employed. The results of
adding a slope aspect layer to the analysis are:
• The 1,982.98 acres of Native Oak/Walnut Woodland is omitted as a
classification.
• Native Oak Woodland comprises 1,270.44 acres of the woodlands in
the study area (715.50 acres within the city limits and 554.94 acres
within the SOI.
• Native Walnut Woodland comprises 711.84 acres of the woodlands
in the study area (447.48 acres within the city boundaries and 264.36
acres within the SOI.
A revised map of natural communities reflecting these changes is provided in
Chapter 4 of the Final EIR. Whereas these acres are likely to reflect a relatively
accurate percent relative woodland cover of 64 percent oak woodland to 36%
walnut woodland, the caveat that woodland habitats should be evaluated on
a project by project site-specific basis remains in place.
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the serious problems that could be precipitated by
misrepresenting the distribution of oaks.
The City should have adequately considered my comments,
and those of others, and required the EIR preparer to
carefully evaluate the plant community mapping.
As an example, consider Steep Canyon:
Excerpt from Figure 3.3-1, Vegetation Communities.
The DEIR maps all of the woodland in the bottom of Steep
Canyon east of Diamond Bar Boulevard as California
Walnut Woodland (yellow screen). Blue arrow added to
show where the photo below was taken from.
Photo: Robert A. Hamilton
Photograph taken on January 4, 2019, showing classic
oak/sycamore woodland in the bottom of Steep Canyon
(i.e., in the area mapped above as “California Walnut
Woodland”).
Photo: Robert A. Hamilton
I could provide numerous other similar examples.
Instead of correcting the problem, the City and EIR
preparer have “doubled down” by reproducing the same
vegetation map in the DEIR that was provided as Figure 2-1
in the Existing Conditions Report, adding an odd canard on
page 3.3-5:
As can be seen in the above description of these alliances,
there can be misinterpretations of the alliance type when
viewed from a distance or in aerial photography,
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particularly in the winter when the winter-deciduous
California walnut has no leaves. For this reason, the
mapping of these alliances in Figure 3.3-1 should be viewed
as being subject to site-specific investigations.
Biologists do not have nearly as much trouble seeing
walnut trees in winter as this statement suggests. The
standard caveat that broad-scale mapping contained in a
General Plan should not be used for CEQA review of
individual projects does not alleviate the need to avoid
misrepresenting the distributions of sensitive resources in
the General Plan. The City’s unwillingness to comply with
multiple requests for accurate representation of oak
woodlands within the City limits — contrasted with
widespread mapping of oaks in the unincorporated Sphere
of Influence — raises questions about whether oaks and
oak woodlands will be adequately protected under the
revised General Plan.
B3-10 RECOMMENDED METHOD FOR CLASSIFYING NATURAL
COMMUNITIES
Since the mid-1990s, the California Department of Fish and
Wildlife (CDFW) and its partners, including the California
Native Plant Society (CNPS), have been working on
classifying vegetation types using standards embodied in
the Survey of California Vegetation, which comply with the
National Vegetation Classification Standard (NVCS;
http://usnvc.org/explore-classification/). The NVCS is a
hierarchical classification, with the most granular level
being the Association. Associations are grouped into
Alliances, Alliances into Groups, and upward, as follows:
Formation Class > Formation Subclass > Formation >
Division > Macrogroup > Group > Alliance > Association.
For CEQA review of specific projects, Appendix A to the
Hamilton Biological Resources Report recommends
The comment appears to be a description of the current industry standards to
be followed when classifying natural communities for CEQA purposes. The
comment states that the described standards apply to the review of specific
projects and recommends classification and mapping of natural communities
at the Alliance of Association level. A general plan update that designates
general land uses and is void of specific plans for future projects within those
land uses is not a specific project.
As a start, it is recommended that all natural communities within the project
footprint be identified using the best means possible. For the purpose of this
assessment and the scale at which the assessment was completed, it was not
practical or necessary to describe and map natural communities at the
granular scale suggested in the comment. Rather, the classification of natural
communities in the study area is initially identified by its general composition
and structure (woodland, shrubland, or grassland/herbland). Within the
description of the general vegetation type, the alliance used by Sawyer et. al.
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classification and mapping of Natural Communities at the
more detailed Alliance or Association level.
The method recommended by CDFW for classifying Natural
Communities and conducting CEQA review reads as
follows:
• Identify all Natural Communities within the project
footprint using the best means possible, for example,
keying them out in the Manual of California Vegetation,
Second Edition (Sawyer et al. 2009) or in classification
or mapping reports from the region, available on
VegCAMP’s Reports and Maps page.
• Refer to the current standard list of Natural
Communities to determine if any of these types are
ranked Sensitive (S1-S3 rank); if so, see CEQA Guidelines
checklist at IVb.
• Other considerations when assessing potential impacts
to Sensitive Natural Communities from a project
include:
1. Compliance with state and federal wetland and
riparian policies and codes, as certain Natural
Communities are restricted to wetlands or
riparian settings.
2. Compliance with the Native Plant Protection Act
and the state and federal Endangered Species
Acts, as some Natural Communities either support
rare species or are defined by the dominance or
presence of such species.
3. Compliance with CEQA Guidelines Section
15065(a), which mandates completion of an EIR if
a project would threaten to eliminate a plant
community.
is provided, followed by the more distinctive plant associations, or alliances
within the study area. Further, the classification system and the vegetation
mapping should be used as a guide for future site-specific assessments.
A listing of sensitive alliances that occur in the study area and their global and
state sensitivity levels is provided in the assessment with the qualifier that all
vegetation associations associated with the listed alliances are considered to
be at the same sensitivity level as the alliance.
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4. Compliance with local regional plans, regulations,
or ordinances that call for consideration of
impacts to Natural Communities.
5. Vegetation types that are not on the state’s
sensitive list but that may be considered rare or
unique to the region under CEQA Guidelines
Section 15125(c).
• If a Natural Community in the project area has not
previously been described, it may be a rare type. In this
case, please contact VegCAMP (Todd Keeler -Wolf or
Diana Hickson) about documenting the Natural
Community.
• If there are Sensitive Natural Communities on your
project site and you need guidance, contact the
appropriate regional staff person through the local
CDFW Regional Office to discuss potential project
impacts; these staff have local knowledge and context.
B3-11 IDENTIFYING SENSITIVE NATURAL COMMUNITIES
The California Department of Fish and Wildlife (CDFW), at
its VegCAMP page, provides guidance on appropriate
methods for “Addressing Sensitive Natural Communities
in Environmental Review”:
https://www.wildlife.ca.gov/Data/VegCAMP/Natural-
Communities#sensitive%20natural%20communities
The State’s guidance consists of the following steps:
• Identify all Natural Communities within the project
footprint using the best means possible, for example,
keying them out in the Manual of California, Second
Edition (Sawyer et al. 2009) or in classification or
mapping reports from the region, available on
VegCAMP’s Reports and Maps page.
The comment describes the State’s guidance in how to address sensitive
natural communities. These guidelines are acknowledged by the City and are
incorporated into Chapter 4 of the Final EIR as a practice in considering the
impacts of future projects.
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• Refer to the current standard list of Natural
Communities to determine if any of these types are
ranked Sensitive (S1-S3 rank); if so, see CEQA Guidelines
checklist at IVb.
• Other considerations when assessing potential impacts
to Sensitive Natural Communities from a project
include:
o Compliance with state and federal wetland and
riparian policies and codes, as certain Natural
Communities are restricted to wetlands or
riparian settings.
o Compliance with the Native Plant Protection
Act and the state and federal Endangered
Species Acts, as some Natural Communities
either support rare species or are defined by
the dominance or presence of such species.
o Compliance with CEQA Guidelines Section
15065(a), which mandates completion of an
EIR if a project would threaten to eliminate a
plant community.
o Compliance with local regional plans,
regulations, or ordinances that call for
consideration of impacts to Natural
Communities.
• Vegetation types that are not on the State’s sensitive
list but that may be considered rare or unique to the
region under CEQA Guidelines Section 15125(c).
• If a Natural Community in the project area has not
previously been described, it may be a rare type. In this
case, please contact VegCAMP (Todd Keeler -Wolf or
Diana Hickson) about documenting the Natural
Community.
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• If there are Sensitive Natural Communities on your
project site and you need guidance, contact the
appropriate regional staff person through the local
CDFW Regional Office to discuss potential project
impacts; these staff have local knowledge and context.
• The Department’s document, Protocols for Surveying
and Evaluating Impacts to Special Status Native Plant
Populations and Natural Communities (PDF) provides
information on reporting.
As recommended in the Hamilton Biological Resources
Report, the City should adopt the above-specified
methods, consistent with State guidance. Doing so would
help to ensure the thoroughness and adequacy of CEQA
documentation completed within the City and its Sphere of
Influence.
B3-12 FAILURE TO IDENTIFY POTENTIAL FOR NATIVE GRASSLANDS
The DEIR characterizes all grasslands in the City and the
Sphere of Influence as “seminatural herbaceous stands,”
and fails to identify any potential for the occurrence of
perennial native grasslands, which are identified as
sensitive by CDFW. Nevertheless, as stated on page 10 of
the Hamilton Biological Resources Report, pockets of
native grassland almost certainly occur within the non-
native annual grasslands:
Areas of perennial grassland, distinguished by possessing
non-trace cover of native grasses, are identified as
Sensitive by CDFW. As examples, the Nassella spp. – Melica
spp. Herbaceous alliance is characterized by having at least
2–5 percent cover of native needlegrass (Nassella spp.) or
other native grasses
(http://vegetation.cnps.org/alliance/536); and the Bromus
The comment indicates the almost certain occurrence of native grasslands
within the study area. Despite the many years of livestock grazing in areas of
non-native grassland, however, it is acknowledged that native grassland
species (e.g., Nassella (Stipa) sp. and Melica californica) could exist in the
study area. In addition, native grassland species may occur in areas of
shrublands, scrub and oak woodland. Chapter 4 of the Final EIR includes
native grasslands as a sensitive natural community potentially occurring in the
study area.
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carinatus – Elymus glaucus herbaceous alliance has
California brome (Bromus carinatus) characteristically
present, with native plants providing more than 10 percent
relative cover (http://vegetation.cnps.org/alliance/499). It
is likely that vernal pools/seasonal ponds occur in the site’s
grasslands, and/or along dirt roads that pass through other
Natural Communities.
The DEIR should identify the potential for areas of native
grassland to occur within the Study Area, and should
recognize any such areas as biologically “sensitive” in their
own right (independent of the occurrence of special-status
plants or wildlife). The General Plan’s resource-protection
policies should address avoidance and/or mitigation of
impacts to native grasslands.
B3-13 ADVERSE EFFECTS OF DEVELOPMENT ON PRESERVED
HABITAT AREAS
An important goal of a General Plan, far from realized in
the DEIR, is to guide future development so as to minimize
adverse effects upon natural communities and declining
native plant and wildlife populations, to the extent
feasible. Beyond the outright removal of natural areas,
which obviously impacts natural resources, nearby
development inevitably degrades and fragments preserved
habitat along the urban/wildland interface. These
secondary, or indirect, impacts have been subject to
intensive study in recent years, to (a) understand and
characterize them, and (b) develop strategies for
minimizing and mitigating them. The DEIR, citing only two
published articles from the peer-reviewed literature, fails
to adequately acknowledge the range of issues that must
be considered when planning future development in and
around Diamond Bar’s remaining natural areas. The
following discussions, including citations from the scientific
The comment identifies a number of the adverse effects that may result from
development within and adjacent to natural communities and the plant and
wildlife populations that occur within them which are generally referred to as
“edge effects. These potentially adverse effects can result in habitat
degradation and/or fragmentation for a variety of reasons, including:
• The introduction of invasive non-native plants.
• Increased frequency of wildfires.
• The introduction of cats and dogs which can act as non-native predators
to native wildlife.
• Increased human presence that can disturb soils, damage vegetation and
increase ambient noise levels.
• The potential introduction of chemicals harmful to plants and wildlife
contained in herbicides and rodenticides.
• General adverse effects on biological systems such as water pollution.
The comment discusses these potential issues in great detail.
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literature, were provided in Appendix A to the Hamilton
Biological Resources Report. Although the DEIR identifies
this report as providing the basis for “assessment of
sensitive habitats and watersheds in this EIR,” most of this
important underlying information has been omitted from
the DEIR and its analyses. To the contrary, the following
information should be taken into account when developing
the General Plan’s land-use policies concerning edge and
fragmentation effects.
Urbanization typically includes residential, commercial,
industrial, and road-related development. At the perimeter
of the built environment is an area known as the urban/
wildland interface, or “development edge.” Edges are
places where natural communities interface, vegetation or
ecological conditions within natural communities interact
(Noss 1983), or patches with differing qualities abut one
another (Ries and Sisk 2004). “Edge effects” are spillover
effects from the adjacent human-modified matrix that
cause physical gradients in light, moisture, noise, etc.
(Camargo and Kapos 1995; Murcia 1995, Sisk et al. 1997)
and/or changes in biotic factors such as predator
communities, density of human-adapted species, and food
availability (Soulé et al. 1988; Matlack 1994; Murcia 1995;
Ries and Sisk 2004). Loss, degradation, and fragmentation
of habitat due to urbanization are the most pervasive
threats to biodiversity in southern California (Soulé 1991).
Edge-related impacts may include:
• Introduction/expansion of invasive exotic vegetation
carried in from vehicles, people, animals or spread from
backyards or fuel modification zones adjacent to
wildlands.
• Increased frequency and/or severity of fire as compared
to natural fire cycles or intensities.
Contrary to the comments implication that the DEIR fails to acknowledge,
adequately describe, and adequately mitigate these adverse effects, ea ch was
disclosed and addressed in the General Plan Update Policies, as summarized
below.
Adverse Effect DEIR Disclosure
Page(s)
GP Policy / Mitigation
Introduction of invasive
non-native plants.
3.3-45 RC-P-13
Increased frequency of
wildfires.
3.7-12 PS-P-15 and PS-P-32 through
PS-P-36
Introduction of cats and
dogs which can act as non-
native predators to native
wildlife.
3.3-45 RC-P-14, MM-BIO-1D and
MM-BIO-6
Increased human presence
that can disturb soils,
damage vegetation and
increase ambient noise
levels.
3.3-45 RC-G-4, RC-P-9, RC-P-11 and
MM-BIO-1D
Potential introduction of
chemicals harmful to plants
and wildlife contained in
herbicides and
rodenticides.
3.7-32 RC-G-7; RC-G-9; RC-P-25; RC-
P-26
Adverse effects on
biological systems such as
water pollution.
3.3-45 RC-P-9; RC-P-11; RC-P-24; LU-
P-56 / MM-BIO-3
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• Companion animals (pets) that often act as predators
of, and/or competitors with, native wildlife.
• Creation and use of trails that often significantly
degrade intact ecosystems through such changes as
increases in soil disturbance, vegetation damage, and
noise.
• Introduction of exotic animals which compete with or
prey on native animals.
• Pesticide exposure can be linked to cancer, endocrine
disruption, reproductive effects, neurotoxicity, kidney
and liver damage, birth defects, and developmental
changes in a wide range of species, from insects to top
predators.
• Influence on earth systems and ecosystem processes,
such as solar radiation, soil richness and erosion, wind
damage, hydrologic cycle, and water pollution that can
affect the natural environment.
Any of these impacts, individually or in combination, can
result in the effective loss or degradation of habitats used
for foraging, breeding or resting, with concomitant effects
on population demographic rates of sensitive s pecies.
The coastal slope of southern California is among the most
highly fragmented and urbanized regions in North America
(Atwood 1993). Urbanization has already claimed more
than 90 percent of the region’s coastal sage scrub habitat,
99 percent of the coastal prairie, and 95 percent of the
vernal pools (McCaull 1994; Mattoni & Longcore 1997;
Bauder & McMillan 1998). A review of studies completed
by Harrison and Bruna (1999) identified a general pattern
of reduction of biological diversity in fragmented habitats
compared with more intact ones, particularly with regard
to habitat specialists. While physical effects associated
Considering the context of Section 15146 of the CEQA Guidelines, the
disclosure of these effects in the Draft EIR is appropriate. As stated in this
section of the guidelines “The degree of specificity required in an EIR will
correspond to the degree of specificity in the underlying activity which is
described in the EIR. An EIR on a construction project will necessarily be more
detailed in the specific effects of the project than will be an EIR on the
adoption of a local general plan or comprehensive zoning ordinance because
the effects of the construction can be predicted with greater accuracy. An EIR
on a project such as the adoption or amendment of comprehensive zoning
ordinance or a local general plan should focus on the secondary effects that
can be expected to follow from the adoption or amendment, but the EIR need
not be as detailed as an EIR on the specific construction projects that might
follow.”
The comment letter, however, is appreciated by the City and is made
available in the Final EIR.
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with edges were predominant among species impacts, they
found evidence for indirect effects including altered
ecological interactions. Fletcher et al. (2007) found that
distance from edge had a stronger effect on species than
did habitat patch size, but they acknowledged the difficulty
in separating those effects empirically. Many southern
California plant and animal species are known to be
sensitive to fragmentation and edge effects; that is, their
abundance declines with fragment size and proximity to an
edge (Wilcove 1985; Soulé et al. 1992; Bolger et al.
1997a,b; Suarez et al. 1998; Burke and Nol 2000).
Wildlife populations are typically changed in proximity to
edges, either by changes in their demographic rates
(survival and fecundity), or through behavioral avoidance
of or attraction to the edge (Sisk et al. 1997; Ries and Sisk
2004). For example, coastal sage scrub areas within 250
meters of urban edges consistently contain significantly
less bare ground and more coarse vegetative litter than do
more “intermediate” or “interior” areas, presumably due
increased human activity/disturbance of the vegetation
structure near edges (Kristan et al. 2003). Increases in
vegetative litter often facilitate growth of non-native plants
(particularly grasses), resulting in a positive feedback loop
likely to enhance plant invasion success (Wolkovich et al.
2009). In another coastal southern California example, the
abundance of native bird species sensitive to disturbance is
typically depressed within 200 to 500 meters (650 to 1640
feet) of an urban edge, and the abundance of disturbance-
tolerant species is elevated up to 1000 meters (3280 feet)
from an urban edge, depending on the species (Bolger et
al. 1997a).
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Habitat fragmentation is usually defined as a landscape
scale process involving habitat loss and breaking apart of
habitats (Fahrig 2003). Habitat fragmentation is among the
most important of all threats to global biodiversity; edge
effects (particularly the diverse physical and biotic
alterations associated with the artificial boundaries of
fragments) are dominant drivers of change in many
fragmented landscapes (Laurance and Bierregaard 1997;
Laurance et al. 2007).
Fragmentation decreases the connectivity of the landscape
while increasing both edge and remnant habitats. Urban
and agricultural development often fragments wildland
ecosystems and creates sharp edges between the natural
and human-altered habitats. Edge effects for many species
indirectly reduce available habitat use or utility in
surrounding remaining areas; these species experience
fine-scale functional habitat losses (e.g., see Bolger et al.
2000; Kristan et al. 2003; Drolet et al. 2016). Losses of
coastal sage scrub in southern California have increased
isolation of the remaining habitat fragments (O’Leary 1990)
and led to calls to preserve and restore landscape
connectivity to permit long-term persistence of native
species with low vagility (e.g., Vandergast et al. 2006).
Fragmentation has a greater relative negative impact on
specialist species (e.g., coastal populations of the Cactus
Wren) that have strict vegetation structure and area
habitat requirements (Soulé et al. 1992). Specialist species
have an increased risk of extirpation in isolated habitat
remnants because the specialized vegetative structures
and/or interspecific relationships on which they depend
are more vulnerable to disruption in these areas (Vaughan
2010). In studies of the coastal sage scrub and chaparral
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systems of coastal southern California, fragment area and
age (time since isolation) were the most important
landscape predictors of the distribution and abundance of
native plants (Soulé et al. 1993), scrub-breeding birds
(Soulé et al. 1988; Crooks et al. 2001), native rodents
(Bolger et al. 1997b), and invertebrates (Suarez et al. 1998;
Bolger et al. 2000).
Edge effects that emanate from the human-dominated
matrix can increase the extinction probability of isolated
populations (Murcia 1995; Woodroffe and Ginsberg 1998).
In studies of coastal sage scrub urban fragments, exotic
cover and distance to the urban edge were the strongest
local predictors of native and exotic carnivore distribution
and abundance (Crooks 2002). These two variables were
correlated, with more exotic cover and less native shrub
cover closer to the urban edge (Crooks 2002).
The increased presence of human-tolerant
“mesopredators” in southern California represents an edge
effect of development; they occur within the developed
matrix and are thus more abundant along the edges of
habitat fragments, and they are effective predators on
birds, bird nests, and other vertebrates in coastal sage
scrub and chaparral systems and elsewhere (Crooks and
Soulé 1999). The mammalian carnivores more typically
detected in coastal southern California habitat fragments
are resource generalists that likely benefit from the
supplemental food resources (e.g., garden fruits and
vegetables, garbage, direct feeding by humans) associated
with residential developments. As a result, the overall
mesopredator abundance, of such species as raccoons,
opossums, and domestic cats, increases at sites with more
exotic plant cover and closer to the urban edge (Crooks
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2002). Although some carnivores within coastal sage scrub
fragments seem tolerant of disturbance, many fragments
have (either actually or effectively) already lost an entire
suite of predator species, including mountain lion, bobcats,
spotted skunks, long-tailed weasels, and badgers (Crooks
2002). Most “interior” sites within such fragments are still
relatively near (within 250 meters of) urban edges (Crooks
2002).
Fragmentation generally increases the amount of edge per
unit land area, and species that are adversely affected by
edges can experience reduced effective area of suitable
habitat (Temple and Cary 1988), which can lead to
increased probability of extirpation/extinction in
fragmented landscapes (Woodroffe and Ginsberg 1998).
For example, diversity of native bees (Hung et al. 2015) and
native rodents (Bolger et al. 1997b) is lower, and
decomposition and nutrient cycling are significantly
reduced (Treseder and McGuire 2009), within fragmented
coastal sage scrub ecosystems as compared to larger core
reserves. Similarly, habitat fragmentation and alterations
of sage scrub habitats likely have reduced both the genetic
connectivity and diversity of coastal-slope populations of
the Cactus Wren in southern California (Barr et al. 2015).
Both Bell’s Sparrows and California Thrashers show strong
evidence of direct, negative behavioral responses to edges
in coastal sage scrub; that is, they are edge-averse (Kristan
et al. 2003), and California Thrashers and California Quail
were found to be more vulnerable to extirpation with
smaller fragment size of the habitat patch (Bolger et al.
1991), demonstrating that both behavioral and
demographic parameters can be involved. Other species in
coastal sage scrub ecosystems, particularly the Cactus
Wren and likely the California Gnatcatcher and San Diego
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Pocket Mouse, are likely vulnerable to fragmentation, but
for these species the mechanism is likely to be associated
only with extirpation vulnerability from habitat
degradation and isolation rather than aversion to the
habitat edge (Kristan et al. 2003). Bolger (et al. 1997b)
found that San Diego coastal sage scrub and chaparral
canyon fragments under 60 acres that had been isolated
for at least 30 years support very few populations of native
rodents, and they suggested that fragments larger than
200 acres in size are needed to sustain native rodent
species populations.
The penetration of exotic species into natural areas can
reduce the effective size of a reserve in proportion to the
distance they penetrate within the reserve: Argentine Ants
serve as an in-depth example of edge effects and
fragmentation. Spatial patterns of Argentine Ant
abundance in scrub communities of southern California
indicate that they are likely invading native habitats from
adjacent developed areas, as most areas sampled greater
than 200 to 250 meters from an urban edge contained
relatively few or no Argentine Ants (Bolger 2007, Mitrovich
et al. 2010). The extent of Argentine Ant invasions in
natural environments is determined in part by inputs of
urban and agricultural water run off (Holway and Suarez
2006). Native ant species were more abundant away from
edges and in areas with predominately native vegetation.
Post-fragmentation edge effects likely reduce the ability of
fragments to retain native ant species; fragments had
fewer native ant species than similar-sized plots within
large unfragmented areas, and fragments with Argentine
ant-free refugia had more native ant species than those
without refugia (Suarez et al. 1998). They displace nearly
all surface-foraging native ant species (Holway and Suarez
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2006) and strongly affect all native ant communities within
about 150 to 200 meters from fragment edges (Suarez et
al. 1998; Holway 2005; Fisher et al. 2002; Bolger 2007;
Mitrovich et al. 2010). Argentine Ants are widespread in
fragmented
coastal scrub habitats in southern California, and much of
the remaining potential habitat for Blainville’s horned
lizards is effectively unsuitable due to the penetration of
Argentine ants and the subsequent displacement of the
native ant species that Coastal Horned Lizards need as prey
(Fisher et al. 2002). Invasion of Argentine ants into coastal
sage scrub has also shown a strong negative effect on the
abundance of the gray shrew (Laakkonen et al. 2001).
An evaluation by the U.S. Environmental Protection Agency
(2008) concluded that each of ten of the most common
active ingredients in rodenticides “poses significant risks to
non-target wildlife when applied as grain-based bait
products. The risks to wildlife are from primary exposure
(direct consumption of rodenticide bait) for all compounds
and secondary exposure (consumption of prey by
predators or scavengers with rodenticide stored in body
tissues) from the anticoagulants.” Thus, the common
practice of setting out bait within or near natural areas can
be expected to have adverse effects upon a range of native
wildlife species.
Finally, in the Santa Monica Mountains of Los Angeles
County, populations of such native amphibians as the
California newt and California treefrog were found to
decline with urbanization of as little as 8% of a given
watershed (Riley et al. 2005). Such faunal community
changes appear to be related to changes in physical stream
habitat, such as fewer pool and more run habitats and
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increased water depth and flow. These changes are
associated with increased erosion and with invasion by
damaging exotic species, such as the red swamp crayfish.
Given the spectrum of indirect effects known to adversely
affect sensitive populations of native plants and wildlife, it
is incumbent upon planning documents, such as the
updated Diamond Bar General Plan, to (1) acknowledge, (2)
adequately describe, and (3) adequately mitigate these
adverse effects. The DEIR fails to achieve these goals.
B3-14 INADEQUATE ANALYSIS OF LOCAL WILDLIFE MOVEMENT
ISSUES
Page 6 of Hamilton Biological’s letter to the City dated
February 21, 2019, criticized the Existing Conditions Report
for its “ineffective and incomplete discussion of wildlife
movement.” Apparently in response, the DEIR provides
additional descriptions of different issues related to wildlife
movement and habitat connectivity. Page 3.3-14 identifies
three “types of corridors and habitats” that exist within the
City and its Sphere of Influence and that “provide habitat
connectivity” to varying degrees:
These include current open space areas and the natural
areas of City parks and the SOI and, to a lesser degree
mature ornamental woodlands. Connectivity can be broken
the physical relationship between landscape elements
whereas functional connectivity describes the degree to
which landscapes actually facilitate or impede the
movement of organisms and processes. Functional
connectivity is a product of both landscape structure and
the response of organisms and processes to this structure.
Thus, functional connectivity or corridor permeability is
both species and landscape-specific. Distinguishing
between these two types of connectivity is important
In view of Section 15146 of the CEQA Guideline the comment and its
associated maps are at a level of detail that exceeds the scope of an EIR for a
General Plan update for several reasons. First, is the assumption that the
choke points are used by wildlife that avoid areas of human inhabitation
when, in fact, species such as coyote, Virginia opossum, striped skunk, Valley
pocket gophers, most birds, gopher snakes, and western fence lizard move
and/or disperse relatively freely through suburban environments. To assert
otherwise would be a speculation in a General Plan update EIR and would be
better addressed on a site-specific basis in concert with policies included in
the General Plan document. A figure identifying choke points, modeled after
those provided in Figures 3a-3d by the commenter, is provided in Chapter 4 of
the Final EIR.
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because structural connectivity does not imply functional
connectivity. That is, in contrast to landscape connectivity
which characterizes the capacity of individual species to
move between areas of habitat via corridors and habitat
linkage zones permeability refers to the degree to which
regional landscapes, encompassing a variety of natural,
semi-natural and developed land cover types, are
conducive to wildlife movement and sustain ecological
processes. Major roadway arterials, suburban
development and areas of intense human activity are
examples of non-natural features that can result in a
corridor being highly impermeable to many wildlife
species.
This generalized discussion, culminating in a negative
statement about how roads and other human activities can
negatively affect the movement of wildlife between
patches of natural habitat, does not represent a useful or
coherent analysis of local wildlife movement and habitat
connectivity issues in and around the City of Diamond Bar.
The Hamilton Biological Resources Report provided
relevant information designed to help the City address this
important large-scale CEQA planning and resource-
management issue. Figures 3a–3d in the report depict 13
areas of extensive (>25 acres) native/naturalized habitat in
Diamond Bar. The figures show potential habitat
connections/choke points for wildlife movement between
blocks of natural open space. Figures 3a–3d, reproduced
on the following pages, provide a practical and useful basis
for characterizing the existing ecological conditions within
Diamond Bar and its Sphere of Influence, without
accounting for such distinctions as the boundaries of
parklands or private lots. If the EIR sincerely intends to
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base its assessment on the Hamilton Biological Resources
Report, the following maps must be acknowledged and
fully incorporated into the CEQA analysis.
[Figure 3a. Natural Open Space Areas]
[Figure 3b. Natural Open Space Areas]
[Figure 3c. Natural Open Space Areas]
[Figure 3d. Natural Open Space Areas]
The DEIR provides no similar exhibits that help to
contextualize the concepts of localized wildlife movement
and habitat connectivity in relation to actual areas of
natural habitat within the City limits. Given the DEIR’s
explicit statement that “The assessment of sensitive
habitats and watersheds in this EIR is based on literature
review and the Hamilton Biological Resources Report,” the
EIR preparer is not justified in omitting this critically
important information in favor of a generalized statement
about negative effects of roads and other development on
wildlife movement and connectivity.
The EIR’s policy approach for mitigating adverse effects of
development upon local wildlife movement and habitat
connectivity is provided in RC-P-11:
Require that all development, including roads and trails,
proposed adjacent to riparian and other biologically
sensitive habitats avoid, to the greatest extent feasible,
significant impacts that would undermine the healthy
natural functioning of those areas. Require that new
development proposed in such locations be designed to:
a. Minimize to the greatest extent possible or eliminate
impacts on environmentally sensitive areas;
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b. Protect the visual seclusion of forage areas from road
intrusion by providing vegetative buffering;
c. Protect wildlife movement linkages to water, food,
shelter, and nesting sites;
d. Allow wildlife and migration access by use of tunnels
or other practical means;
e. Provide vegetation that can be used by wildlife for
cover along roadsides;
The above-listed policy prescriptions may appear
reasonable, but they are not specific to any given area and
have no teeth. In fact, while the DEIR was out for review,
the City has already added “to the greatest extent feasible”
to the first sentence of the proposed policy, further
weakening the proposed policy. They are the type of
guidelines often satisfied in some superficial way, such as
planting vegetation along roadsides, and in many cases
these types of guidelines are completely ignored without
any repercussions. They are unlikely to meaningfully
improve the ecological condition of natural areas scattered
throughout the City that are becoming increasingly
degraded and fragmented by ongoing development.
If the City sincerely intends to, for example, “protect
wildlife movement linkages” and to facilitate “wildlife and
migration access by use of tunnels or other practical
means,” then the updated General Plan should incorporate
my Figures 3a–3d, which highlight numerous “Potential
Habitat Linkages/Choke Points” throughout the City —
specific areas identified as warranting additional scrutiny
and consideration when devising future plans and
subjecting them to CEQA review. See also the following
discussion of Table A, from the Hamilton Biological
Resources Report, which identifies appropriate Resource
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Conservation policy approaches for each substantial area
of natural open space mapped in Figures 3a–3d.
B3-15 RESOURCE PROTECTION RECOMMENDATIONS OMITTED
Referring again to Figures 3a–3d, the Hamilton Biological
Resources Report describes and characterizes the
ecological characteristics of each mapped natural open
space area at a general level of detail appropriate for a
General Plan. The report also makes recommendations
for the establishment of biological protection overlays for
sensitive habitat areas with high ecological values (e.g.,
native woodlands and coastal sage scrub), with recognition
that more detailed, project-specific surveys would be
required to accurately and adequately describe the
ecological resources found in any open space area. The
DEIR ignores this approach in favor of generalized policy
prescriptions that are, in my experience, less likely to
produce good planning results. I provide below Table A
from my report, which lays the foundation for my
recommended planning approach.
[Table A: Resource Protection Recommendations]
The practical benefit of this approach is that it focuses
planning attention on the issues of greatest relevance
within different geographic areas of Diamond Bar and its
Sphere of Influence. Planners can refer to Table A, in
conjunction with Figures 3a–3d, and better evaluate
whether a proposed project is compatible with the General
Plan’s resource protection recommendations for that
particular area. Certainly, nothing is lost by including this
level of detail in the General Plan, so why is this
information from the Hamilton Biological Resources Report
omitted from the DEIR?
As presented in the comment, the establishment of biological protection
overlays goes well beyond the typical scope of a General Plan. While it is
acknowledged that such overlays are useful in the design of
projects, they are more appropriate to include at the specific planning stage
after more detailed information about a project’s biological baseline is
discovered and known.
With regard to the potential habitat linkages/choke points identified in the
comment it should be noted that most are located at sites that are: a) within
City-owned parks or open space; b) privately-owned parks or open space; c)
designated privately-owned open space; d) seemingly cut-off by substantial
barriers (such as freeways); or d) constrained by existing development.
Therefore, they are a component of baseline conditions which the General
Plan update cannot change. However, when considering plans for any public
projects within City-owned parks and open space the City will adhere to
General Plan policies as they relate to movement corridors. A figure
identifying choke points, modeled after those provided in Figures 3a-3d by
the commenter, is provided in Chapter 4 of the Final EIR.
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B3-16 CURRENT INTERPRETATION OF MIGRATORY BIRD TREATY
ACT (MBTA)
Page 3.3-34 of the DEIR provides an outdated
interpretation of this federal legislation, and the impact
analysis on page 3.3-44 states, “Disturbing or destroying
active nests is a violation of the MBTA and nests and eggs
are protected by Fish and Game Code, Section
3503.”
The MBTA of 1918 implemented the 1916 Convention
between the U.S. and Great Britain (for Canada) for the
protection of migratory birds. Later amendments
implemented treaties between the U.S. and Mexico, the
U.S. and Japan, and the U.S. and the Soviet Union (now
Russia). At the heart of the MBTA is this language:
Establishment of a Federal prohibition, unless permitted by
regulations, to “pursue, hunt, take, capture, kill, attempt to
take, capture or kill, possess, offer for sale, sell, offer to
purchase, purchase, deliver for shipment, ship, cause to be
shipped, deliver for transportation, transport, cause to be
transported, carry, or cause to be carried by any means
whatever, receive for shipment, transportation or carriage,
or export, at any time, or in any manner, any migratory
bird, included in the terms of this Convention . . . for the
protection of migratory birds . . . or any part, nest, or egg
of any such bird.” (16 U.S.C. 703)
For many years, the MBTA was subject to broad
interpretation, which in some cases led to prosecution for
violations that were incidental to otherwise lawful
activities. On December 22, 2017, the “Principal Deputy
Solicitor Exercising the Authority of the Solicitor Pursuant
Comment acknowledged. The following paragraph is included in Chapter 4 of
the Final EIR to reflect the current interpretation of the MBTA.
“As a point of clarification and in accordance with revised interpretive
guidelines provided in the Principal Deputy Solicitor Exercising the Authority
of the Solicitor Pursuant to Secretary’s Order 3345 on December 22, 2017, the
MBTA’s prohibition on pursuing, hunting, taking, capturing, killing, or
attempting to do the same applies only to direct and affirmative purposeful
actions that reduce migratory birds, their eggs, or their nests, by killing or
capturing, to human control.”
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to Secretary’s Order 3345” issued revised guidance on the
MBTA5 that reached the following conclusion:
The text, history, and purpose of the MBTA demonstrate
that it is a law limited in relevant part to affirmative and
purposeful actions, such as hunting and poaching, that
reduce migratory birds and their nests and eggs, by killing
or capturing, to human control. Even assuming that the
text could be subject to multiple interpretations, courts
and agencies are to avoid interpreting ambiguous laws in
ways that raise grave Constitutional doubts if alternative
interpretations are available. Interpreting the MBTA to
criminalize incidental takings raises serious due process
concerns and is contrary to the fundamental principle that
ambiguity in criminal statutes must be resolved in favor of
defendants. Based upon the text, history, and purpose of
the MBTA, and consistent with decisions in the Courts of
Appeals for the Fifth, Eighth, and Ninth circuits, there is an
alternative interpretation that avoids these concerns. Thus,
based on the foregoing, we conclude that the MBTA’s
prohibition on pursuing, hunting, taking, capturing, killing,
or attempting to do the same applies only to direct and
affirmative purposeful actions that reduce migratory birds,
their eggs, or their nests, by killing or capturing, to human
control.
Although federal guidance could change again in the
future, the DEIR should acknowledge and describe the
current interpretation of the MBTA.
5 https://www.doi.gov/sites/doi.gov/files/uploads/m-
37050.pdf
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B3-17 TREE PRESERVATION AND PROTECTION ORDINANCE
Pages 3.3-37 and 3.3-38 of the DEIR reviews the City’s Tree
Preservation and Protection Ordinance. Proposed General
Plan Policy RC-P-10, on page 3.3-46, identifies a need to
periodically review and update the Ordinance “as
necessary to reflect current best practices.” In the attached
letter, dated October 31, 2019, Hamilton Biological
proposes changes to the City’s existing ordinance, with
reference to several areas of concern:
• Corrections of outdated references (e.g., the National
Arborists Association no longer exists, having been
replaced by the Tree Care Industry Association) and
typographical errors.
• Changes to bring the City’s ordinance into alignment
with current industry standards. For example, the
County of Los Angeles’ current Oak Woodlands
Conservation Management Plan Guide
(http://planning.lacounty.gov/assets/upl/project/oakw
oodlands_conservation-management-plan-guide.pdf)
requires seven years of maintenance and monitoring of
all oak mitigation plantings, which reflects the
experience of the County that oak plantings may
survive for a few years after planting, only to fail shortly
thereafter.
• Ensuring that funds paid to the City for tree planting are
used to promptly replace impacted trees, and to
prevent against tree mitigation funds being diverted to
other uses.
• Establishing a City-administered program to ensure that
replacement trees are planted in areas suited to their
long-term survival, and not in sensitive habitat areas,
such as coastal sage scrub, where they could cause
adverse ecological effects.
The suggestions provided in the comment are acknowledged and will be
considered when the City revises its Tree Preservation and Protection
Ordinance.
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Consistent with proposed General Plan Policy RC-P-10,
Hamilton Biological requests that the City consider the
proposed changes, to reflect current best practices.
B3-18 COMMENT ON MITIGATION MEASURE BIO-I
This measure would require a habitat evaluation in cases
where a listed species could potentially be impacted. “If no
suitable habitat for listed species is identified within 300
feet of construction or maintenance activities, no further
measures would be required in association with the
project.”
This is not an appropriate mitigation measure to
incorporate into a General Plan, because under CEQA,
evaluation of potential biological impacts of a proposed
action is not limited to species listed as threatened or
endangered by State and/or federal governments. To
comply with CEQA, any project with potential to adversely
affect special-status species should be evaluated, on its
own merits, to determine whether project implementation
could result in significant impacts to any biological
resources. Such impacts could include impacts to California
Species of Special Concern, such as the “coastal” Cactus
Wren; loss or degradation of plant communities that the
State identifies as Sensitive, such as native grasslands;
impairment of a wildlife movement corridor or habitat
linkage; or various other categories of impact that do not
necessarily involve potential “take” of a listed species.
CEQA is much more than a “scorecard” for evaluating
whether a given action might impact a listed species.
As the City understands the comment, the suggestions made recommend that
all sensitive biological resources (special-status species, sensitive natural
communities, habitat linkages, etc.) be evaluated in a manner that is
consistent with the evaluation of federal and State-listed species. Inherent to
the application of the significance criteria provided on page 3.3-40 of the
DEIR, this is intended. Criterion 1 includes consideration of sensitive and
special-status species; Criterion 2 considers sensitive natural communities;
and Criterion 4 considers wildlife movement. Nonetheless, in order to clarify
this intention of MM-BIO-1, the following sentence will be added to the
introductory paragraph for Mitigation Measures on page 3.3-47 of the DEIR:
“It should be noted that assessing potential impacts to which one or more of
the MM-BIO-1 may apply, both direct (on-site) and indirect (off-site) should
be considered.” This is included in Chapter 4 of the Final EIR.
B3-19 MITIGATION RATIOS INADEQUATE
Mitigation Measures BIO-2, BIO-4, and BIO-5 all identify
inadequate mitigation ratios for impacts to sensitive native
Comment acknowledged. Arguably, the use of surrogate mitigation ratios
using quantitative approaches rather than qualitative approaches has its
shortfalls. That is, the application of ratio-derived mitigation does not address
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plant communities, including coastal sage scrub, oak
woodland, and walnut woodland. For each of these
ecologically sensitive communities, some of which are
recognized as sensitive resources in their own right, the
General Plan should strongly encourage avoidance of direct
and indirect impacts.
If impacts cannot be avoided, and existing off-site habitat is
to be purchased as mitigation for the loss of a given area of
sensitive habitat, the minimum ratio should be on the scale
of 5:1, and certainly not 1:1. The ratio of 1:1 for purchase
of existing habitat equates to a net 50% reduction of
community, as no new habitat is being restored on
disturbed/degraded land to replace the valuable sensitive
habitat being lost.
For impacts to sensitive natural communities that cannot
be feasibly avoided, and if 5:1 off-site habitat cannot be
purchased and set aside in perpetuity, the off-site
mitigation requirement should be to restore degraded
habitat in the Chino/Puente Hills, under the auspices of the
Puente Hills Habitat Preservation Authority (PHHPA)7, at a
minimum ratio of 3:1. Restoring habitat at a ratio above
1:1 mitigates for:
• The temporal loss of habitat associated with impacting
one area before another is restored.
• The effects of fragmentation and edge-associated
degradation of preserved habitat areas near the
proposed development.
• The possibility that the restoration effort will fail, partly
or entirely.
the functions and values of the habitat lost compared to the habitat created,
enhanced and/or conserved. Undoubtedly, this matter will be the subject of
future negotiations between project applicants and regulatory agencies. At
this time, however, the City will maintain its past practices.
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A higher mitigation ratio also helps to incentive avoidance
of the impact. The DEIR’s approach to this topic would
leave the City vulnerable to legal challenge due to
providing inadequate mitigation to offset significant
adverse impacts to sensitive natural resources.
7 The PHHPA is dedicated to the acquisition, restoration,
and management of open space in the Puente Hills
for preservation of the land in perpetuity, with the primary
purpose to protect biological diversity.
B3-20 COMMENTS ON MM-BIO-6
Planning of any future development in Diamond Bar and its
Sphere of Influence should take exceptional care to
preserve and enhance the viability of the Puente-Chino
Hills Wildlife Corridor. The authoritative “Missing Middle”
analysis (Conservation Biology Institute 2005) identified
the following wildlife movement issues specifically relevant
to the Puente-Chino Hills Wildlife Corridor in Diamond Bar
and its Sphere of Influence:
• Tonner Canyon Bridge represents the only viable
location for deer, mountain lions, bobcats, and other
species to pass under the 57 Freeway.
• Any development in middle and especially lower
Tonner Canyon could have severe impacts on corridor
function, especially if wildlife access to Tonner Canyon
Bridge is reduced. Any development that blocks access
through the bridge area would make the 57 Freeway a
complete barrier to many species and would likely lead
to wildlife extirpations in segments farther west.
• An earlier plan to build a road running the length of
Tonner Canyon would have split the Chino-Tonner
“subcore” in two, potentially rendering dysfunctional
the critical Tonner Bridge wildlife undercrossing for
The listed issues included in the comment are consistent with MM-BIO-6.
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wide-ranging species such as the mountain lion,
bobcat, and mule deer.
• At least the middle and lower portions of Tonner
Canyon should be conserved, including a prohibition
on any new road or other development that would
fragment this critical habitat block.
• No project should be approved that would increase
traffic under the Tonner Bridge or add any new
impediments (structures, lights, noise, etc.) to the
vicinity of the bridge.
• Restore riparian vegetation along Tonner Creek, where
degraded by oil development activities.
• Fencing may be warranted along the 57 Freeway if
monitoring suggests road mortality is high.
Mitigation Measure MM-BIO-6 should be amended to
incorporate each of these specific conservation
requirements, which are necessary to maintain the viability
of this critically important habitat linkage/wildlife corridor
that passes through Diamond Bar’s Sphere of Influence.
B3-21 COMMENTS ON THE RESOURCE CONSERVATION ELEMENT
Figure 5-1 shows the City open space network, defined as
including “designated open spaces, parks, and the
Diamond Bar Golf Course, which, while developed, serves a
number of open space functions.” Figure 5-1 fails to
account for other open space areas that currently function
as de facto components of the City’s open space network.
Wildlife species do not distinguish between public and
private open spaces, and many native species are
incapable of surviving in a highly diminished, fragmented,
and degraded landscape. Planning for the future
necessarily involves considering the entire extant network
of natural open spaces, public and private.
See response to comment B3-15 above.
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Figures 3a–3d from the Hamilton Biological Resources
Report, reproduced on pages 19–22 of this report, provide
a practical and useful basis for characterizing the existing
ecological conditions within Diamond Bar and its Sphere of
Influence, without accounting for such distinctions as the
boundaries of parklands or private lots. The EIR should
incorporate these figures, and the accompanying Table A,
which identifies appropriate Resource Conservation policy
approaches for each substantial area of natural open space
mapped in Figures 3a–3d.
B3-22 MIS-MAPPING OF NATURAL COMMUNITIES
Figure 5-2 on page 5-11 of the DEIR is identical to Figure
3.3-1 on page 3-3-10 of the DEIR. As discussed at length
previously in this letter, these maps grossly misrepresent
the distribution of oak and walnut woodlands in Diamond
Bar. Both maps must be corrected in the General Plan.
See response to comment B3-9 above.
B3-23 SUMMARY AND CONCLUSION
I appreciate the opportunity to provide these comments to
the City of Diamond Bar regarding this important update to
the General Plan. If you have questions, or wish to discuss
any matters, please do not hesitate to call me at (562) 477-
2181 or send e-mail to robb@hamiltonbiological.com.
Sincerely,
Robert A. Hamilton
President, Hamilton Biological, Inc.
316 Monrovia Avenue
Long Beach, CA 90803
562-477-2181
robb@hamiltonbiological.com
This comment is the closing of the letter. It does not address the adequacy of
the Draft EIR; therefore, no further response is required.
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Attached: Curriculum Vitae
Proposed Amendments to Tree Protection Ordinance
(10/31/19)
Letter to Greg Gubman, City of Diamond Bar (2/21/29)
Cc: Victoria Tang and Andrew Valand, CDFW
Christine Medak, USFWS
Robin Smith, Chair, Diamond Bar-Pomona Valley Sierra
Club Task Force
B3-24 [Literature Cited] This attachment is provided in support of comments B3-2 through B3-22,
addressed above.
B3-25 [Curriculum Vitae] This attachment is provided in support of comments B3-2 through B3-22,
addressed above.
B3-26 [Proposed Amendments to Tree Protection Ordinance
(10/31/19)]
This attachment is provided in support of comment B3-17, addressed above.
B3-27 [Letter to Greg Gubman, City of Diamond Bar (2/21/29)] This attachment is provided in support of comments B3-2 through B3-22,
addressed above.
B4-A RESPONSIBLE LAND USE
B4-A-1 October 31, 2019
Submitted via email to: GLee@DiamondBarCA.Gov
Grace Lee, Senior Planner
City of Diamond Bar
21810 Copley Drive
Diamond Bar California 91765
RE: Comments on Draft Environmental Impact Report,
Diamond Bar General Plan and Climate Action Plan 2040
This comment is the salutation of the letter. It does not address the adequacy
of the Draft EIR; therefore, no further response is required.
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Dear Ms. Lee:
B4-A-2 Diamond Bar is a place we all call home, and we very much
appreciate the opportunity to participate in this public
process. Responsible Land Use (RLU) has reviewed the
proposed Draft Environmental Impact Report (DEIR),
Diamond Bar General Plan (DBGP), and Climate Action Plan
2040 (CAP). Attached to this letter is a table of our
suggested edits, comments, and questions on the DEIR as
well as our general comments, suggestions and concerns
described here.
In general, our members of RLU noted common issues and
concerns:
• Proposed or Preferred Project was not described in the
draft EIR
• Reasonable alternatives were not discussed and
described, or were erroneously written off as infeasible
and not given further consideration, or
• We noted errors and incomplete analysis in coverage of
the CEQA criteria.
• Alternatives described are infeasible due to
assumptions that cannot be fully analyzed for impacts.
• Subsequent release of language changes not reflected
in existing DEIR or DBGP.
• Significant impacts were not mitigated, and were
considered un-mitigatable when reasonable and
feasible alternatives could be proposed.
Comment acknowledged. See responses to comments B4-A-3 through B4-A-
15 below.
B4-A-3 Proposed or Preferred Project was not described in the
draft EIR
The Executive Summary should have a general or high-level
description of the Proposed Project and Community Core
The detailed Project Description in accordance with CEQA Guidelines Section
15124 is provided in DEIR Chapter 2. However, it is acknowledged that that the
omission of the four new Focus Areas in the Executive Summary makes it
difficult to follow the summary comparison of alternatives on Pages ES-5
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Overlay. The Alternatives are described, however, it is
difficult to make a comparison to the Proposed Project to
the other Alternatives on page ES-10. The document is
making a determination that the Proposed Alternative is
the Environmentally Superior Alternative, but because of
the lack of a description it is unclear why. The EIR should
be a stand alone document that does not rely on a
description to be provided separately in the DBGP. In the
final EIR, we request that a Project Description be provided
in both the Executive Summary and Section 2.
through ES-7. To address this, the errata includes a brief description of the four
new Focus Areas, which are cornerstones of the Proposed Project:
• Town Center Mixed Use
• Community Core Overlay
• Neighborhood Mixed Use
• Transit-Oriented Mixed Use
B4-A-4 Reasonable alternatives were not discussed and
described
Include a description of the existing Town Center
Commercial Area at Diamond Bar Blvd and Grand with
existing EIR mitigation measures and planning as a viable
alternative--which is not the same as the No Project
Alternative. Description of the existing town center
utilizing the new EIR mitigation measure requirements and
General Plan policies should also be a reasonable and
feasible alternative for this CEQA analysis. In the context of
comparing impacts, keeping the city center at Diamond Bar
and Grand also has the potential to have less
environmental impact as compared to your preferred
alternative. For example, Vehicles Miles Traveled would be
less, because it is more centrally located for DB residents in
terms of travel to local areas business and therefore should
be described. Also, compared to the Proposed Alternative
the existing city center would not have a Community Core
Overlay and would not be an impact to the golf course,
which would make the existing City Center area a
potentially environmentally superior to the Proposed
Alternative. This alternative should be described and
discussed as to why it does not meet the City’s purpose
and need as described in the EIR.
Under the CEQA Guidelines, an EIR need only evaluate a reasonable range of
alternatives. (CEQA Guidelines section 15126.6(a), (c).) An EIR will not be
found deficient simply because it excludes other potential alternatives from
its analysis. (Cherry Valley Pass Acres & Neighbors v. City of Beaumont (2010)
190 Cal.App.4th 316, 354-355.)
The Draft General Plan’s Community Vision and seven Guiding Principles
envision the “Town Center” concept to be a walkable, mixed-use downtown
with urban amenities, as opposed to the suburban shopping centers that
characterize the intersection of Grand Avenue and Diamond Bar Boulevard
(i.e., the “town center” referenced in Comment B4-A-3).
Section 2.2 of the Project Description identifies the implementation of the
Guiding Principles among the Proposed Project’s objectives. Guiding Principle
No. 3 reads as follows:
Create an inviting Town Center. Foster the development of a vibrant,
pedestrian-oriented Town Center in Diamond Bar that serves as a place for
Diamond Bar’s residents to shop, dine, and gather.
At its June 15, 2017 meeting, the General Plan Advisory Committee (GPAC)
discussed the intersection of Grand Avenue and Diamond Bar Boulevard as a
potential Town Center location. Although there was general agreement that
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the concept of a Town Center at this intersection was attractive in the
abstract, it was rejected as a feasible option, largely due to heavy volumes of
regional traffic that would create barriers to walkability, and thus be unlikely
to fulfill Guiding Principle No. 3. Because the concept of locating the Town
Center at the intersection of Grand Avenue and Diamond Bar Boulevard had
already been deliberated and ultimately rejected in a public forum, it makes
little sense to reconsider the topic in the EIR.
Additionally, it is conclusory to assert that a future Town Center at the
intersection of Grand Avenue and Diamond Bar Boulevard would generate
fewer vehicle miles traveled (VMT) than the Proposed Project’s Town Center
location simply because the latter is less “centrally located.” Please note that
the DEIR Alternatives Analysis found that Alternatives 1, 2 and the No Project
Alternative also generated lower VMT than the Proposed Project (DEIR page
4-25), and were still determined to be environmentally inferior due to other
factors analyzed in Chapter 4. Moreover, potentially lower VMT at the
intersection of Grand Avenue and Diamond Bar Boulevard does not address
the site’s failure to satisfy the Project objectives for a Town Center.
B4-A-5 Significant impacts were not mitigated, and were
considered un-mitigatable when reasonable and feasible
alternatives could be proposed
We understand that impacts to Air Quality may be
significant and un-mitigatable, however why does the City
not suggest building standards and other reasonable
mitigation that would at least contribute to reductions in
air quality impacts? We disagree that there are no feasible
mitigation measures. The City of Diamond Bar should
propose mitigation measures that would reduce emissions
even if it would not reduce those impacts to below
significant thresholds. Planning requirements like LEED
Building Certification or planning requirements that would
include vehicle charging infrastructure would address these
air quality impacts, as well as GHG emissions, and energy
efficiency, and are feasible and cost effective mitigation.
Comment acknowledged. Promoting the increased use of vehicles that do not
emit CO is a feasible mitigation measure that can be incorporated as a
General Plan Policy. Proposed General Plan Policy CR-P-56 will thus read as
follows and is incorporate in the FEIR Errata:
Establish requirements to provide dedicated parking and charging stations for
Electric Vehicles.
As stated on Draft EIR page 3.2-5, CO is primarily emitted from combustion
processes, with the majority of CO emissions generated from mobile sources
(i.e., transportation). While a requirement for the construction of LEED-
Certified buildings may have some level of CO reduction benefits, such
benefits are not likely to be measurable. Green Building Codes and State laws
removing regulatory and economic barriers to rooftop and parking lot solar
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The City of Long Beach has building codes regarding LEED
building policies to reduce energy consumption and GHG
emissions as well as EV Charging Infrastructure. Although,
impacts may be less than significant or un-mitigatable, the
city should provide policies or mitigation measures that
reasonably reduce its carbon footprint.
power systems are likely to continue diminishing the marginal returns of LEED
Certification.
B4-A-6 “A significant amount of land in Diamond Bar would need
to be converted to public parkland to reduce the impact to
a level that is less than significant. Therefore, the impact
remains significant and unavoidable.”
We also disagree with this statement that the impact is
unavoidable or unmitagatable. How does the Core
Community Overlay address recreation opportunities
sufficiently such that the City can be in alignment with the
Quimby Act and meet its ratio of 5 acres per 1000
residents? According to LU-P-54, the City of Diamond Bar
should consider other public uses for public agency lands,
such as the county owned Golf Course. In the event that
the County of Los Angeles wanted to make this land more
broadly available to the general public for recreation, there
should be a Community Park Overlay which identifies a use
of the golf course to address the shortage of recreation
lands to less than significant. Other options, should also be
considered such as greater mitigation ratios (6 acres: 1000
residents) for new developments, or policies that create
mitigation banks that specifically address and identify city
opportunities for future recreation land development.
It is factual that Diamond Bar does not meet the current and proposed
General Plan’s goal of 5 acres of park and recreation facilities for every 1,000
residents, and there is consensus that the City should continue to aspire
toward this goal. This is not an area of controversy.
Should Los Angeles County ever dispose of the golf course, Draft General Plan
Policy LU-P-45 requires that approximately 100 acres be set aside for
parkland. A repurposed golf course could thus serve 20,000 residents, and—
based on the 2016 City population estimate of 57,081--raise the Citywide
parkland ratio from 2.6 acres per 1,000 residents to 4.4 acres per 1,000
residents.
B4-A-7 Errors and Incomplete Analysis of the CEQA Criteria
We noted that on page 1-4, Diamond Bar only listed a
portion of the CEQA Criteria for the environmental
analysis. This is not appropriate, the CEQA analysis does
not just include what was received during the scoping
period or an initial analysis. The CEQA analysis includes the
The Notice of Preparation (NOP) for the DEIR was released on May 31, 2018
and was followed by a 30-day public review period that ran from June 7, 2018
through July 6, 2018, and a public scoping meeting at Diamond Bar City Hall
on June 21, 2018. The NOP identified the 13 environmental factors having
the potential to be affected by the Proposed Project, and which would be
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criteria listed in 2019 CEQA Appendix G Checklist of the
California Environmental Quality Act Statutes and
Guidelines such as Mineral Resources, Agriculture,
Population and Housing, Public Services, Wildfire and
Energy. There should be a discussion on these topics, are
they considered significant or not and why and what
mitigation measures are being proposed to mitigate
significant impacts. Additionally, noise impacts under 3.10
of the Executive Summary Table is incomplete and topics
under 3.11 Noise is an error and should be described as
Public Services and Recreational impacts. Agriculture and
Mineral Resources are also randomly discussed at the end
of the table. Please revise this table organized based on the
CEQA Checklist and address all the Appendix G items.
analyzed in the DEIR. A copy of the NOP is included as Appendix A to the
DEIR.
CEQA Guidelines Section 15128 states: “An EIR shall contain a statement
briefly indicating the reasons that various possible significant effects of a
project were determined not to be significant and were therefore not
discussed in detail in the EIR.” The NOP sets forth the basis for not including a
detailed analysis of agricultural, forestry and mineral resources in the DEIR in
the following statement:
Based on characteristics of the planning area, the following two topic
areas will be included in the Effects Found Not to Be Significant section
of the EIR: agriculture and forestry, and mineral resources. No
agricultural activities or activities related to mineral resources occur
within the Planning Area boundaries, and none of the properties are
designated for agricultural use or as relevant for farmland or mineral
resources by the State of California. Full documentation of the factual
basis for this determination will be included in the EIR. Unless specific
comments are received during the NOP public comment period that
indicate a potential for the project to result in significant impacts, these
less than significant effects will be addressed briefly in the EIR and
“scoped out.” These topic areas are included at the end of Table ES-4 to
reflect that they are indeed analyzed in the Draft EIR and concluded to
have no impact.
Impacts associated with Population are discussed in Chapter 5 due to their
growth-inducing impacts. Impacts associated with housing are discussed in
Chapter 3.9: Land Use and Housing. Impacts associated with Public Services
are discussed in Chapter 3.11: Public Facilities and Recreation. Impacts
associated with Wildfire are discussed in Chapter 3.7: Hazards, Hazardous
Materials, and Wildfire. Impacts associated with Energy are discussed in
Chapter 3.5: Energy, Climate Change, and Greenhouse Gases. These topic
areas are organized into such chapters to consolidate relevant environmental
settings, regulatory settings, and data. Each sub-chapter of Chapter 3 includes
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the criteria listed in the 2019 CEQA Appendix G Checklist of the CEQA Statutes
and Guidelines.
Impacts listed under 3.10: Noise within Table ES-4 are indeed complete. The
2019 CEQA Appendix G Checklist as revised includes only three criteria (three
criteria were revised and three were removed entirely in the most recent
revisions to CEQA Appendix G, resulting in a total of three criteria for Noise).
The heading for 3.11 within Table ES-4 is revised to 3.11: Public Facilities and
Recreation in Chapter 4 of the Final EIR; however, the impacts for Chapter
3.11: Public Facilities and Recreation are accurate as written in the Draft EIR.
B4-A-8 DEIR Choice of alternatives are infeasible due to
assumptions that cannot be fully analyzed for impacts
The Golf Course Overlay is a contingency plan which,
because of all the unknowns associated with its
implementation cannot be fully analyzed at this time.
Therefore, any attempt to incorporate specific areas of the
Golf Course into the current general plan analysis meets
the definition of infeasible in CEQA Guideline § 15364.
Should the Golf Course land ever become available to the
city, a specific plan to implement the overlay will be
required, along with a separate EIR. Therefore, we
question why General Plan Alternative 2 was incorporated
as an Alternative in the DEIR. Alternative 2, as shown on
Figure 4.2-3, and described on DEIR page 4-5, discusses a
possible town center located in the southern portion of
Diamond Bar’s Golf Course. It is interesting that DEIR
author(s) chose this location as one of three alternatives
because this land is currently owned by Los Angeles
County.
The ability for this particular location to become a truly
viable DEIR alternative is dependent upon two undisclosed
Comment acknowledged. See response to B4-A-4.
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assumptions. The two assumptions are: 1) The county will
eventually close or reduce the size of the Golf Course. 2)
The county will not require mitigation or compensation for
the loss of a county property that provides a recreational
service to the local community.
There are a number of reasons those assumptions may
never come to pass, several of which are outlined below:
1. It is impossible to predict at this time when and if
the County will ever, or might ever, decide to
discontinue Golf Course operations.
2. Two, the County has a general plan with its own
parkland requirements to maintain. Specifically,
on page 178, Los Angeles County’s general plan,
Chapter 10, states:
“As specified in P/R Policy 3.1, the County
standard for the provision of parkland is 4 acres of
local parkland per 1,000 residents of the
population in the unincorporated areas, and 6
acres of regional parkland per 1,000 residents of
the total population of Los Angeles County.”
http://planning.lacounty.gov/assets/upl/project/g
p_final-general-plan-ch10.pdf
In order to maintain its own parkland
requirements, the County might therefore
reasonably decide to keep the land for itself and
develop its own park in place of the Golf Course.
One hundred and seventy some odd acres would
make a nice regional County park.
3. Were the County to ever close the golf course, has
there been any precedence set where the County
of Los Angeles deeded lands without adequate
compensation or mitigation for the loss in
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services? Indeed, for quite a number of years, any
hope the city of Diamond Bar might have had of
taking over the golf course property has been
contingent upon the City providing another, fully
developed, functioning golf course facility to the
County in exchange. Should the county ever
terminate golf course operation, it is therefore
reasonable to fully expect the county to demand
compensation in some as yet undetermined form
in exchange for deeding the golf course property
over to the city.
4. It is also possible the County, might decide to use
the property for County purposes other than
recreation. As long as the County, being a
governmental entity, uses the property for
appropriate governmental purposes, those uses
would not fall under the jurisdiction of Diamond
Bar’s general plan. Diamond Bar would have no
say in the County’s land use decision.
Question: given that the conversion of the Golf Course
property was a condition of Alternative 2, why were the
specific conditions, costs, environmental impacts, and
required mitigations of obtaining the golf course property
omitted from the DEIR?
Question: Please explain, in light of the above evidence,
how the City justifies the inclusion of Alternative 2 as a
viable Alternative.
All of the uncertainties, as offered by the evidence above,
make fully analyzing the odds, details, costs and
environmental impacts of Diamond Bar acquiring the Golf
Course property “infeasible.” The uncertainty surrounding
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the acquisition of the property upon which Alternative 2 is
based, therefore makes Alternative 2 “infeasible” to even
consider as a viable alternative at this time.
CEQA Guideline §15364,
“Feasible" means capable of being accomplished in a
successful manner within a reasonable period of time,
taking into account economic, environmental, legal, social,
and technological factors.
B4-A-9 It is important to note that, that the DEIR, on page 3.11-44,
also came to a similar conclusion when it analyzed the
potential for increasing parkland acreage the using the
Golf Course property:
“The proposed General Plan includes several policies and
land use changes aimed at increasing available and
accessible parkland and open space. However, total
parkland at buildout falls severely short of achieving the
parkland ratio of 5.0 acres per 1,000 residents, and no
mitigation is feasible that can make up this gap. Calculation
of the parkland ratio does not include the 134.9 acres of
parkland from the Country Park, which is a private amenity,
or the proposed 100 acres of parkland associated with the
Community Core Overlay, given that Los Angeles County
has not ceased operation of the golf course. Conversion of
these two areas would increase the parkland ratio but is
not feasible at the time of analysis. A significant amount of
land in Diamond Bar would need to be converted to public
parkland to reduce the impact to a level that is less than
significant. Therefore, the impact remains significant and
unavoidable.”
Comment acknowledged. See responses to comments B4-A-4 and B4-A-6.
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Question: please explain the internal DEIR’s internal
discrepancy between the conversion of the Golf Course
property as a condition to Alternative 2 and the statement
on page 3.11-44, quoted above, that because the Golf
Course has not ceased operation, conversion of the Golf
Course property for additional parkland is not feasible at
this time?
B4-A-10 Lack of viable alternatives presented makes the DIER
“fundamentally and basically inadequate”
This DEIR presents only three alternatives. One, a no action
alternative. Two, an appropriate alternative placing
Diamond Bar’s future “downtown” at the existing Sprouts
location. And three, “Alternative 2,” whose land acquisition
issues were discussed above make it infeasible. Striking
Alternative 2, from the DEIR document would leave only
two alternatives.
This is a problem. CEQA Guideline §15126.6 requires that:
An EIR shall describe a range of reasonable alternatives to
the project, or to the location of the project, which would
feasibly attain most of the basic objectives of the project
but would avoid or substantially lessen any of the
significant effects of the project, and evaluate the
comparative merits of the alternatives.
Clearly, one alternative, besides a no action alternative, is
not a “reasonable” set of alternatives. Attempting to
analyze the project with only two alternatives, one of
which being infeasible or status quo, makes it impossible
for this DEIR to select an alternative which is
environmentally superior.
Comment acknowledged. See response to comment B4-A-4.
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Question: Given that CEQA Guideline § 15126.6 specifies
that an EIR shall describe a range of reasonable
alternatives to the project. How many alternatives does
the city believe an EIR needs in order to be in compliance
with this Guideline?
The fact that the city has failed under CEQA guidelines to
present a “reasonable” number of alternatives therefore
makes this DEIR subject to CEQA §15088.5 (a)(4).
Recirculation of the DEIR is required when:
The draft EIR was so fundamentally and basically
inadequate and conclusory in nature that meaningful
public review and comment were precluded. (Mountain
Lion
Coalition v. Fish and Game.)
It is therefore incumbent upon the City to withdraw the
current DEIR, replace it with a new version which includes
a “reasonable” number of “feasible” alternatives, and then
recirculate it according to CEQA §15088.5.
Each of the alternatives should avoid or lessen one or more
of the significant effects identified as resulting from the
proposed general plan. A reasonable range of alternatives
would typically include different levels of density and
compactness, different locations and types of uses for
future development, and different general plan policies.
The alternatives should not all have the same level of
impacts. This discussion of alternatives will enable
environmental considerations to influence the ultimate
design of the general plan.
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B4-A-11 General Plan Language Revisions during the public review
period
The General Plan Action Committee spent the last three
years finding consensus on general plan policy and goal
language with citizens, the city, and themselves. They gave
their final, approved policy language to the city at their
final meeting last March. The city then wrote the draft
general plan using that language with minimal changes,
and presented it, along with the DEIR, to the public for a
45-day comment period on Sept 16.
Then, on September 25, in the middle of the comment
period, Diamond Bar's City Council and Planning
Commission held a joint "study" session. During that
session, city council members complained the draft general
plan language was not "flexible enough." They ordered the
city manager to give them a revised language proposal
which removed the word "require" from general plan
policies, and "soften" any policy language which was “non-
flexible.” At the next "study" session on October 8, the city
manager offered 40 or so pages of revised policy changes
to the city council.
The actual language revisions were not made public until
72 hours before the subsequent “study” session on
October 8. The revisions, which were part of the second
“study” session’s agenda and staff report, were spread
throughout all elements of the general plan document. All
in all, over 170 policies were revised or deleted.
One or two policy changes might be considered
“insignificant.” However, large numbers of “insignificant”
changes, in this case, over 170, spread throughout the
Comment acknowledged. General Plan policies are not “optional.” The
proposed “softened” language is intended to allow a certain level of flexibility
in the making of General Plan consistency determinations in light of all
factors, as opposed to being compelled to conclude that a proposed project
or action is inconsistent with the General Plan simply because one applicable
policy is so inflexible that no other finding could be made, regardless of the
overall merits of such project or action. Revisions to the policy language carry
the same intent and applicability and do not have a material effect on the
conclusions made in the Draft EIR.
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entire general plan document, easily add up to and meet
CEQA guideline §15088.5's definition of “significant”
change.
It is unquestionably the right of the city council to amend
general plan language. If the city planned on having
“study” sessions which might include language revisions by
the City Council, those study sessions should have occurred
before placing the draft General Plane and EIR our for
public review.
Revising that much policy language in the middle of the 45-
day comment period places the public, Responsible
Agencies, Trustee agencies, and state, federal, and local
agencies which may have jurisdiction over the project, in
an impossible position for several reasons:
1, besides being part of the draft general plan language,
many of the policies revised are also found in the DEIR as
important mitigation policies. DEIR comments, submitted
before the adopted language revisions, were therefore
made on the basis of mitigation policy language which no
longer exists. Those commenters deserve the right and a
reasonable amount of time, specifically another 45-day
comment period, at the very minimum, in which to
consider the import of the language revisions with respect
to their comments, and change their comments as
necessary.
2, even for those few who might actually be aware of the
general plan language revisions, and are considering
making comments, evaluating mitigation measures
potentially based upon 170 plus revised policies, which are
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spread across the 691page DEIR document, is no trivial
task. Especially when one must check every single general
plan policy listed in the DEIR as a mitigation against the
“study” session’s staff report to see which ones have, in
fact, been revised. All of the extra effort required to sort
out those language revisions places those individuals and
agencies under an unreasonable burden during the few
remaining days of the comment period. Those individuals
and agencies deserve more time to wade through all of the
confusion, specifically, another 45-day comment period to
reconsider their comments.
3, the city has made no effort to inform the public, and
agencies who were not physically present at the second
“study” session, that such a large number of general plan
policy revisions were, in fact, made. No where, on the
general plan’s website can one find the news that general
plan policy and goal revisions have, in fact, been adopted.
To the interested, but uninformed, web site visitor, the fact
of those adopted language revisions would remain a
mystery.
Any reasonable individual would have expected the city to
at least notify, according to California Public Resources
Code § 21092.2, the affected agencies and the general
public of the general plan language revisions. Those
individuals deserve the right to make their own
determination about whether or not the policy revisions
are indeed, “insignificant.” This is especially so, considering
the importance of the document in question: a brand new
general plan, the first in over twenty years, with a
projected life span to the year 2040.
4, Adopting those language revisions during what was
purported to be a “study” session in the middle of the
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comment period was disingenuous. It is true that the city
widely publicized the date and time of the “study”
sessions. That said, many residents, especially those who
had spent so much time involved in the general plan
language creation process, took the title of the meetings,
“study sessions,” to mean just that: study. They believed
the sessions were intended to “study” the general plan and
DEIR documents, and have the city staff explain the
contents of those documents. No one who saw any of the
“study” session announcement information ever dreamed
that the city council would make such drastic language
revisions during those “study sessions.”
The fact that such sweeping general plan policy revisions
were adopted, in such an unexpected manner, with respect
to the public’s and affected agencies’ expectations, in the
middle of the public comment period, at a misidentified
meeting, those facts, all this evidence, adds up to and
meets the conditions of CEQA Guideline §15088.5
(Recirculation of an EIR Prior to Certification). That article
should be, must be invoked according to CEQA Guideline
§15086. The newly adopted language changes must be
incorporated into the draft general plan and DEIR
language, with all of the revisions clearly shown. The
general plan, along with the entire DEIR must be then
recirculated for another 45-day comment period.
Finally, it should be noted, in this regard, that §15088.5 (e)
specifically states: “a decision not to recirculate an EIR
must be supported by substantial evidence in the
administrative record.” The fact that such evidence simply
does not exist, should be enough, all by itself, to require
the DEIR, with mitigation policy language revisions clearly
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marked, to be recirculated according to the above statues
for another 45-day comment period.
B4-A-12 General Plan language revisions impact DEIR and CAP
mitigations
Impact 3.5-1 Implementation of the Proposed Project
would not generate greenhouse gas emissions, either
directly or indirectly, that may have a significant impact on
the environment. (less than significant)
We question the DEIR’s conclusion that the proposed
project’s impact on climate change and greenhouse gases
will have a less than a significant impact and does not
require mitigation. The finding is based on the projected
reductions that were calculated using the General Plan
policies and CAP policies that were abruptly revised 3
weeks after publication of the DEIR. The DEIR maintains:
The CAP, once adopted, will serve as a Qualified GHG
Reduction Strategy,” enabling streamlined environmental
review of future development projects, in accordance with
CEQA. The future emissions inventory for the City of
Diamond Bar incorporates reductions from State actions,
General Plan land use and circulation systems, and
additional General Plan Policies. This analysis shows the
projected GHG emissions in 2030 and in 2040 will be well
below the standards established in the 2017 CARB Scoping
Plan. Thus, additional GHG reduction actions are not
required for the City to have and maintain a Qualified GHG
Reduction Strategy. (3.5-47)
The tables presented in the CAP (3-12 to 3-19) provide
quantified reductions in MTCO2e to justify that the Project
Revisions to the General Plan policy language do not change the intent of
these policies or significantly reduce their applicability in the Climate Action
Plan modified emissions forecast. The Climate Action Plan uses the
methodology outlined in the California Air Pollution Control Officers
Association’s (CAPCOA) Quantifying Greenhouse Gas Mitigation Measures
report to quantify emissions reductions from the General Plan policies. For
each category of policies, calculation of emissions reductions assumed the
minimum percentage reduction in the range provided by CAPCOA. In multiple
cases, the General Plan policies were not assumed to be mandatory or
universally implemented. Therefore, the calculated reductions in MTCO2e are
still valid and revisions to the policies do not have any material effect on
conclusions made in the CAP and Chapter 3.5.
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will meet regulatory targets. The CAP Table 3-8 which
forecast GHG reductions attributes “the largest reduction
from parking policies, followed by pedestrian improvement
and increased connectivity, transportation improvements,
electric vehicle infrastructure, traffic calming, and bikeway
system improvements” (CAP 3-18).
However, it is not possible to fully analyze and fully verify
the validity of these calculations in the narrow window of
time since the policies were revised by the City Council at
the October 8, 2019 Study Session. Properly evaluating the
validity of the revised CAP is critical since “once adopted,
[it] will serve as the Qualified GHG Reduction Strategy,
enabling streamlined environmental review of future
development projects in accordance with CEQA” (3.5-39).
How is this still true after the changes in the relevant
language? Will additional mitigation policies be provided
to support streamlining the CEQA process?
A significant number of the recently revised general plan
policies were cited (to improve walkability, reduce VMT,
promote electric vehicle infrastructure, improve bikeways
and calm traffic) to support this calculation. Here are some
examples:
• LU-P-17: Promote Require that site designs that
create active street frontages and introduce
pedestrian-scaled street networks and street
designs.
• LU-P-42: Avoid expanses of surface parking and
require encourage the consolidation and location
of parking to the rear or side of buildings where
appropriate.
• LU-P-48: Promote Require convenient, attractive,
and safe pedestrian, bicycle, and transit
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connections both within the Community Core area
and between the Community Core and
surrounding neighborhoods and other
destinations within Diamond Bar.
• CC-P-57: Improve Promote the pedestrian
comfort and safety of crosswalks along South Brea
Canyon Road and South Lemon Avenue.
• CR-P-55: Consider the establishment of
Incorporate common bicycle parking
requirements for appropriate uses—including
multifamily residential and office—in the
Municipal Code.
• CR-P-56: Establish requirements to provide
Encourage dedicated parking and charging
stations for electric vehicles.
• RC-P-20: Require Encourage the implementation
of the latest water conservation technologies into
new developments.
• RC-P-21: Require Ensure builders developers to
provide information to prospective buyers or
tenants within the City of Diamond Bar regarding
droughttolerant planting concepts.
• CHS-P-5: As opportunities and resource become
available, implement street design features that
facilitate walking and biking in both new and
established areas. Require a minimum standard of
these features for all new developments where
appropriate and feasible.
• CHS-P-14: Encourage the development of Develop
and incorporate "destinations"—such as the
clusters of commercial uses that draw residents
from the entire community into the
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Neighborhood Mixed Use, the TransitOriented
Mixed Use, and the Town Center focus areas.
• CHS-P-15 Establish opportunities for Encourage
the establishment of gathering areas in new
neighborhoods.
• CHS-P-33 Plan Encourage land uses to reduce
vehicle miles traveled (VMT), prioritizing infill
development and incorporating vertical and
horizontal mixed-use development, public transit,
and active transportation facilities where
appropriate, recognizing that the transportation
sector is the largest source of GHG emissions in
Diamond Bar and in California more broadly.
• CHS-P-35 Use the City's CAP as the platform when
considering for outlining and implementing
measures to improve energy conservation and
increase renewable energy use in existing and
new development.
As we have noted in a previous document submission to
the public record, according to the General Plan Guidelines
developed by the Office of Planning and Research (OPR),
“It is better to adopt no policy than to adopt a policy with
no backbone.” (Office of Planning and Research. “General
Plan Guidelines.” 382.)
In addition, for a policy to be counted towards “mitigating
of a plan’s impacts,” it must be expressed as mandatory.
(Office of Planning and Research. “General Plan
Guidelines.” 382.)
The above changes lead us to specifically ask, what is the
likelihood of these policies being implemented? How do
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they support the CAP’s calculations that expected targets
would be met? What additional mitigation policies could
be provided if the targets are not met and the impacts
become significant? After all, encouragement,
consideration, and promotion are not enforceable forms of
policy. They suggest a lack of commitment by the city to
pursue these goals.
B4-A-13 We also question the forecasted construction emissions
that are “based on an expectation of a maximum of 10
percent of the total build-out area that could be potentially
developed in any year” (3.5-28). What policies provide the
foundation for this expectation? The DEIR also
acknowledges that it is a “conservative estimate” and
“projects would extend for more than one year, and
therefore, would increase total project emissions” (3.5-29).
In addition, the report acknowledges that “development
anticipated by the Proposed Project could result in a
significant impact, if the per capita emissions from the
2030 and 2030 (buildout) years exceed the reduction
targets identified in the CAP” (3.5-33). With the revisions
to the policy language, how is it certain that the city will
achieve the projected targets? What mitigation measures
will be provided since there is the possibility that impacts
could become significant? Why not provide these at this
point rather than assume it will not be necessary?
Construction emissions could be less significant than the “conservative”
estimate for air quality emissions; i.e. here “to be conservative” assumes the
worst-case construction scenario for emissions.
B4-A-14 Moreover, the DEIR assumes “implementation of the
Proposed Project’s policies aimed at resource conservation
and VMT reduction would reduce overall GHG emissions
compared to existing conditions and would ensure that the
City’s 2030 and 2040 levels of GHG emissions would not
exceed the respective emission targets” (3.5-35).
However, the same project has “the potential to convert
oak woodland to developed areas” (3.538). The report
identifies potential areas of development that would
The General Plan and Climate Action Plan do not propose any new
development in areas that include oak woodland. New development is
concentrated in four focus areas, three of which are already developed
(development of the Community Core Overlay would occur on the Golf
Course and would require an additional master plan and EIR). See Figure 3.9-
3: Proposed Land Use Change Areas in the Draft EIR and Figure 3.3-1: Natural
Communities included in Chapter 4 of the Final EIR. Should unmapped oak
woodland occur in areas of new development, the acreage would be minimal
but is unknown. As discussed in the Climate Action Plan, the 2040 GHG
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disrupt woodland and that “for every acre of forest
removed, an average of 0.85 MTCO2 sequestration is lost”
(3.5-35). Therefore, the DEIR should also calculate the
amount of MTCO2 sequestration the loss of mature trees
could cost the city. We would also suggest including the
trees in the Golf Course. Doing so would properly evaluate
the benefit of these biological resources to the reduction
of GHG and climate change.
The DEIR’s claim that the impact would be less than
significant relies on calculations in the CAP that were based
on different policy language. As such, how would other
responsible agencies be able to vet this claim is still true or
provide well-informed comments since they may not be
aware of the policy language changes made at the October
8th Joint Meeting? It would be reasonable to expect that
the DEIR and General Plan/CAP (with its revisions clearly
marked with strike-outs) should be recirculated for an
additional comment period.
Please explain how the organizations and agencies outlined
in CEQA Guideline § 15086, who, because no specific
announcement was made about the October 8th language
revisions on Diamond Bar’s General Plan website, might
reasonably be able to make informed comments as a result
of the general plan language revisions.
emissions target is 4.0 MTCO2e per capita per year, or 266,740 MTCO2e per
year. This target is used in the Draft EIR as a threshold to determine
significance. Forecasted emissions under the General Plan land use and
circulation system in 2040 would be 251,074 MTCO2e per year assuming
implementation of State actions and relevant General Plan policies cited in
the CAP and Draft EIR. Given an average 0.85 MTCO2e sequestration is lost
per acre of forest removed, 18,430 acres of forest would need to be removed
to exceed the threshold used in this analysis. The Planning Area encompasses
13,039 acres, of which 3,949 acres are designated as Parks and Open Space
and 2,030 acres are designated as Vacant. 3,513 acres of the Planning Area
are in the Sphere of Influence (SOI), which is designated as a Significant
Ecological Area and limits new development. Therefore, while the amount of
oak woodland that could potentially be converted under the General Plan is
unknown, it is not extensive enough to result in a new significant impact and
the claim is justified.
B4-A-15 Concerns expressed about the haste with which language
revisions were made
While we respect concerns about the need for appropriate
general plan policy language flexibility, we believe the
language balance has swung too far the other way. We
urge that the Planning Commission and the City Council
take the time to carefully consider and fully understand the
value of strategically making the determination of where
Comment acknowledged.
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flexible language is appropriate, and specific language is
needed. The General Plan document under consideration
will guide the city for the next 20 years. We believe it is
appropriate, nay imperative, that we take the time to
rethink the hastily revised language, and other issues
mentioned above, and then recirculate the draft General
Plan and DEIR for another 45 days.
B4-A-16 Thank you, for the opportunity to participate and comment
on the DBGP, EIR and CAP. If you have any questions or
comments on any of the comments provided, we are
available to discuss or provide any clarifications.
Sincerely,
R Lee Paulson
President
This comment is the closing of the letter and does not address the adequacy
of the Draft EIR; therefore, no further response is required.
B4-A-17 [Diamond Bar General Plan Update Website Homepage] This attachment is provided in support of comments B4-A-11 and B4-A-15,
addressed above.
B4-A-18 [Diamond Bar General Plan Update Website Documents
Page]
This attachment is provided in support of comments B4-A-11 and B4-A-15,
addressed above.
B4-B RESPONSIBLE LAND USE
B4-B-1 Page ES-1: The Executive Summary should have a general
or high-level description of the Proposed Project and
Community Core Overlay. The Alternatives are described,
however it is difficult to make a comparison to the
Proposed Project to the other Alternatives on page ES-10.
See response to comment B4-A-3.
B4-B-2 Page ES-1: There needs to be a description of the Proposed
Project as a part of the Executive Summary.
See response to comment B4-A-3.
B4-B-3 Page ES-1: Question: Why was the general or high-level
description of the Proposed Project and Community Core
Overlay omitted from the DEIR?
See response to comment B4-A-3.
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B4-B-4 Page ES-1: The document is making a determination that
the Proposed Alternative is the Environmentally Superior
Alternative, but because of the lack of a description it is
unclear why.
A detailed Alternatives Analysis pursuant to CEQA Guidelines Section 15126.6
is provided in Chapter 4 of the Draft EIR. The purpose of the Executive
Summary is to provide a “brief summary of the proposed actions and its
consequences” (CEQA Guidelines Section 15123) as a roadmap to the EIR
document as a whole.
B4-B-5 Page ES-1: Question: How does the city plan to create a
clear description of why the Proposed Alternative is the
Environmentally Superior Alternative?
See response to Comment B4-B-4.
B4-B-6 Page ES-5: Description of the existing town center utilizing
the new EIR requirements should also be a reasonable and
feasible alternative for this CEQA analysis. It may not be a
preferred option for the City, but it is a reasonable and
feasible alternative.
Question: Why was the existing town center with existing
EIR mitigation measures and planning not considered as a
viable alternative?
See response to comment B4-A-4.
B4-B-7 Page ES-5: Also, in the context of comparing impacts,
keeping the city center at Diamond Bar and Grand also has
the potential to have less environmental impact as
compared to your preferred alternative. For example,
Vehicles Miles Traveled would be less, because it is more
centrally located for DB residents in terms of travel to local
areas business and therefore should be described.
Question: Why was creating a city center at Diamond Bar
Blvd and Grand not considered as a viable alternative for
the DEIR?
See response to comment B4-A-4.
B4-B-8 Page ES-5: Also, compared to the Proposed Alternative
there would not be an impact to the golf course, which
would make the existing City Center area environmentally
superior to the Proposed Alternative.
This comment introduces yet another suggested alternative: The Town Center
at the intersection of Grand Avenue and Diamond Bar Boulevard combined
with the deletion of the Community Core Overlay. Also see response to
Comment B4-B-12.
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B4-B-9 Page ES-7: Another topic that was discussed in General
Planning Meetings was the lack of recreational space for
residents.
It is factual that Diamond Bar does not meet the current and proposed
General Plan’s goal of 5 acres of park and recreation facilities for every 1,000
residents, and there is consensus that the City should continue to aspire
toward this goal. This is not an area of controversy.
B4-B-10 Page ES-8: We disagree that there are no feasible
mitigation measures. The City of Diamond Bar should
propose mitigation measures that would reduce emissions
even if it would not reduce those impacts to below
significant thresholds. Planning requirements like LEED
Building Certification or planning requirements that would
include vehicle charging infrastructure would address these
air
quality impacts and are feasible and cost-effective
mitigation.
Question: We understand that impacts to Air Quality may
be significant and un-mitigatable, however why does the
City not suggest building standards and other reasonable
mitigation that would at least contribute to reductions in
air quality impacts?
See response to comment B4-A-5.
B4-B-11 Page ES-10: We agree with the DEIR on this. Any discussion
about using Golf Course land for parks is, at this time,
purely speculative. All that can be safely stated in the DEIR
is that should the Golf Course
land become available to the city of Diamond Bar,
allocating a substantial portion of that site for parkland
purposes should be seriously considered and part of the
specific plan and EIR for the site.
Comment acknowledged.
B4-B-12 Page ES-11: Alternative 1 does not have a Community Core
Overlay, and has less environmental impacts than the
proposed project. Therefore, it is the Environmentally
Superior Alternative.
The Alternatives analysis concludes that Alternative 1 is environmentally inferior
to the Proposed Project expressly because it does not incorporate the
Community Core Overlay. The basis for this conclusion is set forth in the DEIR
under Section 4.4 (Environmentally Superior Alternative):
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Question: why has Alternative 1 been considered
Environmentally inferior, given it has less environmental
impacts than other alternatives?
Reduced development and population growth under Alternative 1 may slightly
reduce impacts of the Proposed Project; however, implementation of
Alternative 1 would not be sufficient to reduce significant and unavoidable
impacts on air quality, historic resources, and VMT to a level that is less than
significant. Additionally, differences in population, housing, and jobs growth can
be partially attributed to differences in buildout methodology between the
Alternatives and the Proposed Project. Most significantly, Alternative 1 would
not include the Community Core overlay, which would require a master plan to
ensure comprehensive implementation of reuse of the Golf Course should the
County of Los Angeles choose to discontinue its operation. Implementation of
the Community Core overlay would address the pervasive issue in the City of
Diamond Bar, and Los Angeles County as a whole, of equitable access to
parkland as it would require that at least 100 contiguous acres of the Golf
Course be developed as public parkland. The southern portion of the Golf
Course site would be developed as a mix of uses, including high-density housing,
and would be relatively accessible by the Metrolink station. Given that the
Proposed Project was originally based on Alternative 1, is generally found to be
more compatible with the surrounding environment, and provides additional
benefits through the Community Core designation, the Proposed Project is
considered environmentally superior.
B4-B-13 Page ES-11: This also does not take into consideration a
third alternative which could be implementation of the
new environmental requirements for the existing city
center at the intersection of Diamond Bar Blvd and Grand,
which would have less impacts for
VMT
See response to comment B4-B-7.
B4-B-14 Page ES-11: This statement is unclear.
Question: why is the Preferred or Proposed Alternative’s
Community Core Overlay is not fully analyzed for this
alternative?
The General Plan 2040 & Climate Action Plan Environmental Impact Report is a
program EIR. Page ES-1 of the DEIR (page ES-1) describes the purpose of a
program EIR as follows:
As a programmatic document, this EIR does not assess site-specific impacts. Any
future development anticipated by the Proposed Project would be subject to
individual, site-specific environmental review, as required by State law. This EIR
represents the best effort to evaluate the Proposed Project given its planning
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The conversion or loss of the County Golf Course would
have to be mitigated for under existing county
requirements. Therefore, the full connected actions and
environmental impacts
cannot be fully described in this analysis if there is no
discussion of the impacts associated with the replacement
for the existing golf course.
The preferred alternative’s Community Core Overlay would
have to undergo a separate CEQA analysis. It is premature
to assume that the Preferred Alternative is Environmentally
Superior to other Alternatives if the Community Core
Overlay is not fully analyzed, both for the impacts to
potential onsite resources or the associated mitigation for
a golf course relocation.
Question: why is the Preferred Alternative considered
Environmentally Superior to other Alternatives if the
Community Core Overlay is not fully analyzed, both for the
impacts to potential onsite resources or the associated
mitigation for a golf course relocation?
Question: why is the language at the left even in the DEIR?
Additionally, the General Plan describes Environmental
Justice issues particularly exposure to pollution such as
Ozone, Diesel,
Traffic etc. The census tract that includes the Golf Course
is very high for these elements in the CalEnviroScreen 3.0.
Therefore, future residential development would cause
greater exposure to these future residents and should be
discussed in this document.
horizon through the year 2040. It can be anticipated that conditions will change;
however, the assumptions used are the best available at the time of preparation
and reflect existing knowledge of patterns of development.
The above statement is consistent Section 15168 (Program EIR) of the CEQA
Guidelines, to wit, subsection 15168(c): “Subsequent activities in the program
must be examined in the light of the program EIR to determine whether an
additional environmental document must be prepared.”
As set forth in the Project Description (DEIR Chapter 2), the Community Core
Overlay is a component of the Proposed Project, and has thus been analyzed to
the extent required for a program EIR. The opportunity to perform a “site-
specific environmental review” would be triggered if and when the County
discontinues golf course operations (one of the prerequisites for implementing
the Community Core Overlay Goals and Policies), at which time air quality, noise
and other potential impacts will be evaluated and influence the planned
location of residential and other sensitive uses within the planning area.
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Question: Why was greater exposure to pollution such as
Ozone, Diesel, Traffic etc, not discussed with respect to
potential residential development in this area?
B4-B-15 Page ES-12: There needs to be an existing City Center
Alternative (Diamond Bar and Grand) that is different from
the No Project Alternative. This is a reasonable alternative
that has not been discussed but has the potential for being
environmentally superior.
Question: what the existing City Center at Diamond Bar
and Grand not considered as another alternative?
See response to comment B4-B-2.
B4-B-16 Page ES-12: Question: Are there no impacts associated
with the eligible State Scenic Highway along Highway 57 in
Tonner Canyon?
Tonner Canyon is located within the SOI, and is presently under the jurisdiction
of Los Angeles County. Although the SOI is a component o f the Planning Area,
the Draft General Plan recognizes the County’s Significant Ecological Area
designation for Tonner Canyon, and does not propose any new land use
designations in anticipation of the area eventually annexing into the City. The
DEIR addresses the aesthetic setting of the Significant Ecological Area on page
3.1-7, which provides the basis for the No Impact determination:
The County is also in the midst of updating its Significant Ecological Areas
Ordinance (as of May of 2019). Significant Ecological Areas (SEAs) include land
that is identified to hold important biological resources representing the wide-
ranging biodiversity of the County, based on the criteria for SEA designation
established by the General Plan and as mapped in the SEA Policy Map (Figure
3.1-3). As shown on this map, all of Diamond Bar’s Sphere of Influence is
considered an SEA. The SEA Ordinance establishes regulations to conserve the
unique biological and physical diversity of the natural communities within
Significant Ecological Areas (SEA) by requiring development to be designed to
avoid and minimize impacts on SEA Resources. The regulation of development
in SEAs also seeks to preserve scenic resources.
B4-B-17 Page ES-12: I did not find any reference to this source?
Question: Where are the references to this source?
Dyett & Bhatia Urban and Regional Planners is the primary author of the
DEIR. Table ES-3 is a summary of the impacts identified in Chapters 3 and 4
of the DEIR.
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B4-B-18 Page ES-55/56: The noise impacts under 3.10 of the Table
is incomplete in that it does not include all the 2019 CEQA
Appendix G Checklist Items.
CEQA Guidelines Appendix G is an optional template for the preparation of
initial studies, not for the preparation of EIRs. The DEIR was prep ared
pursuant to CEQA Guidelines Sections 15120 et seq (Contents of
Environmental Impact Reports). DEIR Chapter 3 provides a detailed
assessment of potential impacts that could result from implementation of the
Proposed Project.
B4-B-19 Page ES-55/56: Additionally, the items under 3.11 Noise is
an error and should be described as Public Services and
Recreational impacts. (see Appendix G of 2019 CEQA
Checklist)
Comment acknowledged.
B4-B-20 Page ES-57: The criteria listed in the table only show three
criteria, but the CEQA Checklist Appendix G includes six
criteria. Therefore, this table in incomplete.
Question: Why aren’t the complete list of criteria in CEQA
Checklist Appendix G included in the table referenced
here?
See response to comment B4-B-18.
B4-B-21 Page ES-57: This is also incomplete. There are more criteria
in Appendix G. Globally please review the entire checklist
to complete the EIR analysis.
Question: Why wasn’t the entire list of criteria in Appendix
G listed here?
See response to comment B4-B-18.
B4-B-22 Page ES-59: What is this? This table clearly attempts to
identify the CEQA Appendix G Checklist. However, this
section just throws Agriculture, Mineral Resources at the
end randomly.
Please revise this table to organize base on the CEQA
Checklist and address all the Appendix G items, whether or
See response to comment B4-A-7.
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not there are significant impacts, and what mitigation
measures are being
proposed to mitigate those impacts. Why was this table
formatted in a way that does not follow a similar format
from the CEQA Checklist?
B4-B-23 Page 1-4: This is not appropriate, the CEQA analysis does
not just include what was received during the scoping
period. The CEQA analysis includes the criteria listed in
Appendix G and also includes Mineral Resources,
Agriculture, Population and Housing, Public Services, etc.
There should be a discussion on these topics, even though
they are either no impacts or they are considered not
significant.
Question: why does the existing analysis only include those
items mentioned in the Scoping Comments?
Question: Why was a full CEQA analysis of all criteria not
done here?
See Responses to Comments B4-B-18 and B4-B-22.
B4-B-24 Page 2-1: Add pagination to enable comments. Comment acknowledged that page numbering is not provided on the title
page (Page 2-1) or on pages containing figures, which is consistent with the
page numbering format throughout the DEIR. All other pages are numbered.
B4-B-25 Page 2-1: This section does not include a description of the
Project. There is also no description of the project in the
Executive Summary. The EIR should describe the Proposed
Project without having to flip to the General Plan as a
reference and description.
Chapter 2 comprises a Project Description pursuant to Section 15124 of the
CEQA Guidelines.
B4-B-26 Page 2-1: Question: Why was a complete description of the
Project placed in the Executive Summary?
CEQA Guidelines Sections 15120 et seq (Contents of Environmental Impact
Reports) sets forth discrete criteria for the contents of the Executive Summary
(CEQA Guidelines Section 15123) and the Project Description (CEQA
Guidelines Section 15124). The Executive Summary and Project Description
are thus presented within separate, eponymous chapters.
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B4-B-27 Page 1-6: We ask for an opportunity to review and
comment on the MMRP. It is important to understand the
city’s expectations of developers and the city’s
responsibility in compliance oversight to ensure that the
Mitigation Measures are complied with.
Question: To what extent will the public have the ability to
review and comment on the MMRP?
The MMRP will be included in the Planning Commission and City Council
agenda packets prepared in advance of the EIR certification and Proposed
Project approval hearing dates.
B4-B-28 Page 2-1: Recommended Change) This EIR analyzes the
proposed Diamond Bar General Plan 2040 (General Plan)
and the proposed Diamond Bar Climate Action Plan (CAP),
together referred to as the "Proposed Project." Under
California Government Code Section 65300 et. seq., cities
are required to prepare a general plan that establishes
policies and standards for future development, circulation,
housing affordability, and resource protection for the entire
planning area. By law, a general plan must be an
integrated, internally consistent statement of city policies.
California Government Code Section 65302 requires that
the general plan…
Question: Why are the laws and regulations being used
here in the Project Description?
This is all being described in Chapter 1. Should move this
statement into Chapter 1 and include a Project Description.
This is an editorial commentary unrelated to the environmental analysis, and is
acknowledged. See response to comment B4-B-26 regarding the location of the
Project Description.
B4-B-29 Chapter 3.10: There needs to be a map identifying the
obvious noise sensitive receptors: schools, hospitals, places
of worship. This would be feasible to do in this document,
but an analysis for a project should also be done at the
time of a proposal to the planning commission if there are
any sensitive receptors within a reasonable radius.
Typically, a map identifying noise sensitive receptors is provided at the
project-level to illustrate the distance between the receptors and the
project’s noise generating construction and operation activities. As this
General Plan Update EIR is at the program-level for future development, the
potential noise sensitive receptors would potentially be any of the receptors.
Therefore, for this program-level EIR it is sufficient to list the types of
receptors that are noise sensitive (residences, schools, churches, hospitals)
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Question: where is the map that identifies the obvious
noise sensitive receptors?
but not locate every receptor on a map, as not all maybe in proximity to be
impacted at the project-level.
B4-B-30 Page 3.10-9: Question: At what time of day are these noise
levels assumed?
Table 3.10-1 lists the Community Noise Equivalent Level (CNEL) readings for the
identified roadway segments. DEIR page 3.10-5 defines CNEL to be the average
noise level over a 24-hour period:
The Community Noise Equivalent Level (CNEL) is the average A-weighted
noise level during a 24-hour day that includes an addition of 5 dB to
measured noise levels between the hours of 7:00 a.m. to 10:00 p.m. and
an addition of 10 dB to noise levels between the hours of 10:00 p.m. to
7:00 a.m. to account for noise sensitivity in the evening and nighttime,
respectively.
For an explanation of A-weighting, please refer to DEIR page 3.10-2.
B4-B-31 Page 3.10-30: The noise contours should include the
freeways.
The freeways are the loudest and constant source of noise
in the City.
Question: Why are the freeways not included in this
section’s analysis?
Existing and future traffic noise contours were estimated based on traffic
volumes for roadway segments provided by the project traffic consultant,
which did not provide volumes for the freeways. Traffic volumes are used to
estimate the distances of reference noise contour lines in CNEL from each
roadway; however, the estimate is based only on the noise generated by
traffic volumes, with no site specific consideration of localized barrier
attenuation such as intervening topography and barriers. Therefore, these
noise contours are not used for site specific impact analysis of existing and
future traffic noise levels at receptors, but they provide a visual
characterization of the extent (distance) of traffic noise levels at distance from
roadways.
B4-B-32 Page 3.10-32: Please ensure that the map also includes the
freeways as well. This Proposed General Plan will need to
take into consideration freeway improvements and
reasonable mitigation such as sound walls as mitigation.
Question: Will the final EIR ensure the map also includes
the freeways?
See responses to comments B4-B-31 and B4-B-33.
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B4-B-33 Page 3.10-32: Question: Will the final EIR take into
consideration freeway improvements and reasonable
mitigation such as sound walls?
With the adoption of General Plan policies PS-P-45 through PS-P-52, potential
noise impacts will be less than significant. Please refer to Policies PS-P-49 and
PS-P-50 regarding the preparation of noise analyses and the construction of
noise barriers to mitigate project-specific noise impacts.
B4-B-34 Page 3.10-32: Recommended Change) Mitigation Measure:
In areas identified as Noise Sensitive Receptors, such as
schools, hospitals and places of worship measures to
mitigate noise generated that exceed XX will include
measures such as sound barriers or other methods to
reduce noise generation below significant levels.
From another EIR:
The following are typical practices for construction
equipment selection (or preferences) and expected function
that can help reduce noise. Pneumatic impact tools and
equipment used at the construction site would have intake
and exhaust mufflers recommended by the manufacturers
thereof, to meet relevant noise limitations. Provide impact
noise producing equipment (i.e., jackhammers and
pavement breaker[s]) with noise attenuating shields,
shrouds or portable barriers or enclosures, to reduce
operating noise. Line or cover hoppers, storage bins, and
chutes with sound-deadening material (e.g., apply wood or
rubber liners to metal bin impact surfaces).
Provide upgraded mufflers, acoustical lining, or acoustical
paneling for other noisy equipment, including internal
combustion engines. Use alternative procedures of
construction and select a combination of techniques that
generate the least overall noise and vibration. Use
construction equipment manufactured or mo dified to
reduce noise and vibration emissions, such as: Electric
instead of diesel-powered equipment. - Hydraulic tools
The suggested mitigation language can be found in numerous EIRs and
Mitigation Monitoring and Reporting Programs (MMRPs), and are more suited
to project-level documents. Draft General Plan Policy PF-P-49 sets forth site-
specific noise analyses for the purpose of developing tailored noise mitigation
measures for noise-sensitive uses and any other “development proposals where
project noise exposure would be other than normally or conditionally
acceptable as specified in Table 7-10 (of the General Plan).”
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instead of pneumatic tools. - Electric saws instead of air- or
gasoline-driven saws.
No mitigation is offered for Noise Sensitive Receptors such
as schools and places of worship. Below on page 3.10 -33
you state no mitigation measures are required.
We have offered additional mitigation measure language
that can reasonably reduce noise impacts around residents
and noise sensitive
receptors.
B4-B-35 Page 3.10-13: Question: At what levels are construction
vibration noises impacting structures, and what mitigation
is recommended?
Construction equipment and activities varying vibration levels, as shown in EIR
Table 3.10-12, in which vibration levels dissipate rapidly with distances of
approximately 50 -100 feet to a level less than Caltrans and FTA vibration
criteria for damage to structures (depending upon the building materials of
the structure). EIR Table 3-10-15 provides FTA criteria for vibration threshold
levels for various structurally constructed building materials, and the
distances at which these varying vibration levels would not be exceeded.
Project-level analysis would determine potential vibration impacts to
structures depending upon the type of construction equipment operating, the
distance from structures, and the structural strength of the structures based
on their building materials.
B4-B-36 Page 3.10-13: Look at Caltrans 2013 Vibration Guidance
Manual
as a reference.
Comment acknowledged. The EIR utilized and references FTA vibration
criteria (FTA 2018), which Caltrans utilizes in their vibration guidance.
Therefore, FTA and Caltrans vibration criteria is similar.
B4-B-37 Page ES-16: We noted that CR-P-56 was modified since the
draft EIR was released for public comment. Globally we
recommend all edits that were implemented after the draft
EIR release be documented similarly so that the public is
aware of any edits that occurred.
All proposed revisions to the General Plan policy language are incorporated in
Chapter 4 of the Final EIR.
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Question: will all edits which were implemented after the
draft EIR release be documented as they were in the Study
Session Staff Report?
B4-B-38 Page ES-16: We strongly suggest that the language for CR-
P-56 be retained as originally written.
Question: Will the language for CR-P-56 be reconsidered in
light of evidence presented below?
See response to comment B4-A-5.
B4-B-39 Page ES-16: The implementation or installation of electrical
infrastructure is reasonable if built into the cost of
construction for new business and parking lots. However,
businesses are reluctant to install
charging station infrastructure after parking lot completion
because of the cost of tearing up the parking lot and
getting separate permits for installation. Other cities, such
as the City of Long Beach, have implemented policies or
ordinances that required planning for this type of electrical
vehicle infrastructure as part of the permitting process.
Similarly, the City of Diamond Bar should include the
requirement of LEED Certification or equivalent to
encourage energy efficiency and reduction of GHG for new
construction.
Question: Will the city include the requirement of LEED
Certification or equivalent to encourage energy efficiency
and reduction of GHG for new construction?
See response to comment B4-B-10.
B4-B-40 Page ES-16: The Community Overlay if implemented to
include high density housing would occur in an area
already deemed an area of high-level pollutant impacts
along the 60 and 57 freeway, please refer
See response to comment B4-B-14
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to the CalEnviroScreen 3.0 for this Census Tracs in this
area. Certain elements like diesel emissions are already at
very high levels, with the City of Industry Census tract
6,037,403,312 already at a Pollution Burden Level of 93%.
Question: Will the final EIR take the above evidence into
consideration, should the Community Overlay still be
seriously considered in that document?
B4-B-41 Page 3.2-10: Recommended Change) (page 3.2-10)
California Air Resources Board (GARB)
Was this supposed to be CARB? Also fix citation at bottom
of table.
CARB is the correct acronym. Unable to locate the noted typographical error in
the DEIR.
B4-B-42 Page 3.2-15: Within this paragraph you mention the types
of sensitive receptors such as schools, long-term care
facilities. These entities do exist, and since you mention
them, it is feasible to identify them. Particularly public
schools. You also have identified development areas in
your planning for land use changes or future development,
therefore it would be feasible and practical to identify
those sensitive resources in the vicinity of areas proposed
for land use changes (eg. schools near high density
residential).
Question: Will the final EIR document identify and map
sensitive receptors such as schools, long-term care
facilities?
See response to comment B4-B-29.
B4-B-43 Page 3.2-19: Question: What are you showing here? This
table is incomplete and does not show any data.
Table 3.2-4 shows the California Ambient Air Quality Standards and National
Ambient Air Quality Standards for ozone, nitrogen dioxide, carbon monoxide,
sulfur dioxide, particulate matter, lead, visibility reducing particles, sulfates,
hydrogen sulfide, and vinyl chloride. Table 3.2-4 provides the maximum
allowable concentration and method for determination for commonly used
time periods such as 1-hour concentration, 8-hour concentration, and annual
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arithmetic mean. Where dashes are provided, no standard exists. The table is
not intended to show data; rather, it is intended to consolidate air quality
standards that are referenced in the analysis of Chapter 3.2.
B4-B-44 Page 3.2-32/37: These are good goals to try and achieve in
the City’s General Plan. The following LU and CRs do
provide the appropriate language: LU-G-4; LU-G-9; CR-P-
33; CR-P-56; RC-P-28; RC-P-33;RC-P-34;
RC-P-35 and others.
However, not all of these General Plan Policies relate to
reduction of air quality impacts, such as RC-P-19. It is not
clear that this is a General Plan Policy that improves air
quality. Or is it possibly a measure to reduce increased
pressure on Utilities?
Comment acknowledged. Policy RC-P-19 is included to reduce increased
pressure on utilities. As recommended by the comment, policy RC-P-19 is struck
out from this chapter in Chapter 4 of the Final EIR.
B4-B-45 Page 3.2-35: Recommended Change) (RC-P-30): Ensure
Require that new development projects are designed and
implemented to be consistent with the South Coast Air
Quality Management Plan.
The language to ensure puts the onus on the Planning
Commission to check with AQMP. Requiring that the
development project has to comply with SCAQMD puts the
requirement on the developer and not the Diamond Bar
Planning
Commission.
Question: Does the city agree that it is incumbent upon
developers to design and implement project consistent
with the South Coast Air Quality Management Plan?
Question: Therefore, is it reasonable to require them to do
that?
Comment acknowledged. Recommended policy language to remain as initially
drafted.
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Question: Will the final EIR change the general plan
language back to its original form? If not, how will this
affect the Planning Commission?
B4-B-46 Page 3.2-35: Recommended Change) RC-P-33. New
development projects are required to Consult with SCAQMD
when siting new facilities with dust, odors, or Toxic Air
Contaminant (TAC) emissions to avoid siting those facilities
near sensitive receptors and avoid siting sensitive receptors
near sources of air pollution. Require proposed land uses
that produce TACs to incorporate setbacks and design
features that reduce TACs at the source to minimize
potential impacts from TACs. For new or modified land uses
that have the potential to emit dust, odors, or TACs that
would impact sensitive receptors require the business
owners to notify the SCAQMD, and residents and
businesses adjacent to the proposed use prior to business
license or building permit issuance. (New from SCAQMD
Guidance)
This language should put the requirement on the
developer to consult and provide that documentation with
the Planning Commission regarding their consultation with
the SCAQMD. It
is not clear who, the City of DB or the developer must
consult with the SCAQMD.
Question: Is it not reasonable to require developers to
consult with SCAQMD when siting new facilities with dust,
odors, or Toxic Air Contaminant (TAC) emissions to avoid
siting those facilities near sensitive receptors?
Question: Will the EIR final draft then require this? How?
Comment acknowledged. The recommended language for Policy RC-P-33 (now
RC-P-29) is revised in the Public Hearing Draft General Plan and Chapter 4 of the
Final EIR as follows:
RC-P-3329. Ensure that project applicants Cconsult with SCAQMD when
siting new facilities with dust, odors, or Toxic Air Contaminant (TAC) emissions to
avoid siting those facilities near sensitive receptors and avoid si ting sensitive
receptors near sources of air pollution. Require proposed land uses that produce
TACs to incorporate setbacks and design features that reduce TACs at the source
to minimize potential impacts from TACs. For new or modified land uses that have
the potential to emit dust, odors, or TACs that would impact sensitive receptors
require the business owners to notify the SCAQMD, and residents and businesses
adjacent to the proposed use prior to business license or building permit issuance.
(New from SCAQMD Guidance)
Examples of facilities that may emit TACs as identified by the SCAQMD
include dry cleaners, gas stations, auto body shops, furniture repair shops,
warehouses, printing shops, landfills, recycling and transfer stations, and
freeways and roadways. Refer to SCAQMD guidance for the most current list
of facilities that may emit TACs
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B4-B-47 Page 3.2-35: Also, the sensitive receptors should be
identified, where feasible in this document so that it can be
determined whether the newly provided land use changes
would potentially impact sensitive receptors such as
schools. This language is pushing that requirement on a
case by case basis without the opportunity to comment
here. Also, this is left to the developer to determine where
there are sensitive receptors. However, it is feasible to
identify existing sensitive receptors in 2020. Also, knowing
where the known sensitive receptors exist will assist the
Planning Commission determine whether notification to
the SCAQMD is required.
See response to Comment B4-B-29.
B4-B-48 Page 3.2-33: We like this statement. This says that every
project needs to go through some sort of consistency
review to ensure that it meets
compliance with AQMP. (AQMD?)
Comment acknowledged. See Draft EIR page 3.2-21 regarding SCAQMD’s Air
Quality Management Plans (AQMPs), particularly the 2016 AQMP.
B4-B-49 Page 3.2-37: Recommended Change) Mitigation Measures
With the implementation of the Proposed General Plan
Policies, impacts are less than significant and therefore
additional mitigation measures are not None required.
The paragraph preceding the listing of Goals and Policies, commencing on page
3.2-34, is substantially similar to the proposed language in this comment.
B4-B-50 Page 3.2-37: The General Plan Policies are proposed
measures to address impacts and reduce impacts
to Air and GHG emissions.
However, many policies are now worded as
optional rather than mandatory to implement.
Question: How will the revised policies, which
have been softened, still qualify as mitigations for
impacts to AIR and CHG emissions under CEQA?
General Plan policies are not “optional.” The proposed “softened” language is
intended to allow a certain level of flexibility in the making of General Plan
consistency determinations in light of all factors, as opposed to being compelled
to conclude that a proposed project or action is inconsistent with the General
Plan simply because one applicable policy is so inflexible that no other finding
could be made, regardless of the overall merits of such project or action.
B4-B-51 Page 3.2-37: Recommended Change) Require all off-road
diesel equipment greater than 50 horsepower (hp) used for
this Project to meet current USEPA standards, which are
Comment acknowledged. The revised language proposed in the comment is
added to MM-AQ-1 and included in Chapter 4 of the Final EIR and MMRP.
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currently Tier 4 final off-road emission standards or
equivalent. Such equipment shall be outfitted with Best
Available Control Technology (BACT) devices including a
California Air Resources Board certified Level 3 Diesel
Particulate Filter (DPF) or equivalent. This DPF will reduce
diesel particulate matter and NOX emissions during
construction activities.
This mitigation measure should reflect the changing
standards for USEPA from 2020-2040.
Question: How does the city plan to make this mitigation
measure reflect the changing standards for USEPA from
2020-2040?
B4-B-52 Page 3.2-37: It is not clear how this measure addresses air
quality impacts. Is this meant for reduction of impacts of
water use?
Question: How does this measure address air quality
impacts?
Is this instead meant for reduction of impacts of water
use?
Comment acknowledged. Policy CHS-P-57 is included to reduce increased
pressure on utilities and water use. As recommended by the comment, policy
CHS-P-57 is struck out from this chapter in Chapter 4 of the Final EIR.
B4-B-53 Page 3.3-1: Formatting issues with the table. Comment acknowledged.
B4-B-54 Fig. 3.3-2: Brea Canyon that is referenced on page 3.3-8 as
it leaves the channel in the City of Diamond Bar and enters
the SOI is not identified in figure 3.3-2. Nor is the
channelized portion of the creek.
Question: How will the EIR final draft fix this oversight?
Figure 3.3-2 is revised to show Brea Canyon Channel and included in Chapter 4
of the Final EIR.
B4-B-55 Page 3.3-12: Recommended Change) United States Fish
and Wildlife Service (USFWS) designated critical habitat for
Comment acknowledged. The revised language proposed in the comment is
added and included in Chapter 4 of the Final EIR.
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listed plant or wildlife species does not occur within the
Planning Area. The nearest critical habitat for the Coastal
California gnatcatcher is located within the southwest
corner of the SOI and extends through the Puente-Chino
Hills Wildlife Corridor in the City of Puente Hills located to
the southwest of the SOI.
Additional critical habitat for the Coastal California
gnatcatcher is located within the City of Walnut and within
Chino Hills State Park but is not adjacent to the Planning
Area boundaries.
Modified the existing language to be more descriptive of
where known CAGN Critical Habitat exists. A map would
be more helpful.
B4-B-56 Page 3.3-45: Recommended Change) Promote Require the
use of native and drought-tolerant vegetation in
landscaping, site stablization and restoration where
practical to prevent the spread of invasive plant species
into natural open spaces.
The EIR acknowledges that the spread of invasive species
can take over or outcompete native vegetation. Therefore,
the requirement should be clear that native seed mixes or
plantings should be used in both landscaping, site
stabilization for SWPPP, and revegetation purposes.
Question: How will the EIR final draft clarify this
requirement with the proposed language changes or the
equivalent?
Also, the statement should be clearer to the developer
what is expected of them and why.
Comment acknowledged. Proposed General Plan Goal RC -G-6 is revised as
follows and is included in Chapter 4 of the Final EIR:
Utilize native and drought-tolerant vegetation in landscaping, site
stabilization and restoration where practical to prevent the spread of
invasive plant species into natural open spaces
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Question: Will the EIR final draft clarify what is
expected of the developer in this requirement?
How?
Although the language of where practical is
included for flexibility, native vegetation should be
considered first.
B4-B-57 Page 3.3-45: Recommended Change) Require, as part of
the environmental
review process, prior to approval of discretionary
development projects
involving parcels within, adjacent to, or surrounding a
significant biological resource area, a biotic resources
evaluation of the site by a qualified biologist., Focused
plant surveys shall be conducted at the appropriate time of
year, and local reference populations checked to ensure
detectability of the target species. requiring that time-
specific
issues such as the seasonal cycle of plantsWildlife shall also
be evaluated by a qualified biologist through appropriate
survey or trapping techniques necessary to determine
presence. and migration of wildlife are evaluated. Such
evaluation shall analyze the existing and potential natural
resources of a given site following at least one site visit as
well as the potential for significant adverse impacts on
biological resources. The report and shall identify measures
to avoid, minimize, or mitigate any impacts to species that
have been observed or have the potential of being present
on the site. that would degrade its healthy function. In
approving any permit based on the evaluation, the City
shall require implementation of mitigation measures
supported by the evaluation, or work with the applicant to
Comment acknowledged. Proposed General Plan Policy RC-P-9 is revised
as proposed by the commenter and is included in Chapter 4 of the Final
EIR.
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modify the project if mitigation is determined not to be
adequate to reduce the impacts to a non-significant level.
We suggest language that is clear on the steps needed to
be able to adequately identify sensitive resources and
proposal of measures specifically that would avoid,
minimize or mitigate impacts to species present or
potentially present. These requirements are common on
most development projects in areas impacting potentially
sensitive habitats.
Question: How will the EIR final draft clarify the language
here with the proposed revisions or the equivalent?
Question: If the final EIR does not plan to clarify the
language here with the proposed revisions or the
equivalent, what are the city’s reasons for not doing so?
That is, by deciding not to clarify the
language, is the city suggesting that adequately identifying
sensitive resources and proposal of measures specifically
that would avoid, minimize or mitigate impacts to species
present or potentially present not important?
B4-B-58 Page 3.3-47: Recommended Change) MM-BIO-1A: To the
extent feasible the preconstruction surveys shall be
completed when species are in bloom, typically between
May and June and reference populations checked. Two
species, the white rabbit-tobacco and San Bernardino aster,
are perennial herbs that grow up to three feet in height and
can be identified by their dried stalks and leaves following
their blooming period.
Suggest adding language on checking reference
populations. This will ensure accuracy of detecting the
Comment acknowledged. The commenter’s recommended revision to
Mitigation Measure MM-BIO-1A is added to Chapter 4 of the Final EIR
and is included in the MMRP.
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target species. This requirement is not burdensome and
often can be determined by
a phone call to a local botanist or checking websites and
providing that documentation.
Question: will the final EIR draft include the revised
language suggestions to ensure accuracy of detecting the
target species?
B4-B-59 Page 3.3-47: Recommended Change) MM-BIO-1B: At a
minimum, the plan shall include a description of the
existing conditions of the project and receiver site(s),
transplanting and/or seed collection/off-site seeding or
installation methods, an adaptive two-year monitoring
program, any other necessary monitoring procedures, plant
spacing, and maintenance requirements. In the event, that
the City of DB determines that agreed success criteria are
not met, additional remediation may be required beyond
the two-year maintenance/monitoring period to ensure
mitigation requirements are met.
We believe that there needs to be assurance that the
developer has met obligations. In the two years of
monitoring, there should be adaptive management of the
site to ensure success. If the mitigation measure
conditions are not met in the established two-year
timeframe, it should be the developer’s obligation to meet
those mitigation measure requirements. If it is not clear to
the developer on what the requirements are, the City of
Diamond Bar risks being the responsible party for the
additional restoration expense, or the establishment of
exotic weed species that could
exacerbate the potential for wildfire.
Comment acknowledged. The commenter’s recommended revision t o
Mitigation Measure MM-BIO-1B is added to Chapter 4 of the Final EIR
and is included in the MMRP.
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Question: will the EIR final draft ensure that If the
mitigation measure conditions are not met in the
established two-year time frame, that it will be the
developer’s obligation to meet those mitigation measure
requirements?
Question: if the answer to the above question is yes, how,
specifically, will the EIR final draft ensure this?
B4-B-60 Page 3.3-53: Can this MM BIO-4 align with the City of
Diamond Bar Municipal Code, Chapter 22.38 - Tree
Preservation and Protection? (Page 3.3-38) There are
described restoration ratios that are inconsistent with BIO -
4. We believe the ratios described are more reasonable
biologically.
Question: will this also reference the Oak Woodland
Protection Act 2016?
If the answer to the above question is no, why not?
There are several examples of city documents that
reference oak tree mitigation ratios based on diameter at
breast height and the ratio of replacement.
We request an ordinance or policy for a no net policy of
trees for the city. A sufficient ratio for tree replacement
based on size or canopy cover should be established.
Please consult references
such as Urban Forestry Program Manual. Or suggest
elements in a MM on elements that need to be addressed
in an ordinance to enable this MM to mitigate impacts to
less than significant.
DBMC Chapter 22.38 will be updated to conform to MM BIO-4. The ordinance
revising DBMC Chapter 22.38 will be subject to public hearings before the
Planning Commission and City Council, and the Oak Woodland Protection Act of
2016 and other relevant input will be considered in the drafting of the
ordinance.
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Although RC-P-10 - development of a mature native tree
ordinance. We should request to review and comment on
the measures in that ordinance.
B4-B-61 Page 3.3-48: Recommended Change) MM-BIO-1D: The City
shall implement an Environmental Awareness Training
Program on its web site intended to increase awareness to
developers, residents and city workers of the sensitive
plants, wildlife and associated habitats that occur in the
preserved open space areas. The intention purpose of the
program shall be to inform developers, city workers and
residents. The program shall address safety, environmental
resource sensitivities and impacts associated with the
introduction of invasive plant species as a result of new
development. At a minimum, the Environme ntal Awareness
Program shall include the following components:
encourage Provide, on the City website, information about
proactive conservation efforts among for the residents and
city to help conserve the habitats in the preserved open
space. The program shall address impacts associated with
the introduction of invasive plant species as a result of new
development. At a minimum, the Environmental Awareness
Program shall include the following components:
This language reads as voluntary.
Question: What requirements will there be for City
Workers or Developers to review the online program?
We recommend that an Environmental and Safety
Awareness Training be developed that is tailored and
specific to each project based on resource or safety
Comment acknowledged. “Developers” has been added as being subject to the
Environmental Awareness Program in MM-BIO-1D in Chapter 4 of the Final EIR.
Proposed improvements, such as trails, will be subject to General Plan Goals
and Policies, the mitigation measures set forth in the FEIR and project-specific
CEQA review. It is not reasonable or feasible to compel residents to participate
in a training program as proposed. The first bullet point under Mitigation
Measure 3.3-48 imposes reasonable requirements to increase environmental
awareness.
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concerns. It would be the responsibility of the contractor
or developer to ensure that the workers have taken the
awareness training and provide documentation if
requested by the City of Diamond Bar.
Question, given the need for all individuals at all levels of
responsibility to be trained, will the city make the proposed
language revisions?
Question: if the answer to the above question is no, what
are the reasons for that decision?
B4-B-62 Page 3.3-48: Recommended Change) MM-BIO-D: For
informational purposes, Tthe City shall provide future
project applicants a brochure which includes a list of
sensitive plant and tree species to avoid impacting as well
as suggested plant palettes to be used in residential
landscaping near natural areas to prevent the introduction
of invasive plant species to the surrounding natural
communities.
Not only is it important to suggest the types of plants to
avoid, it is also important to identify sensitive plant and
tree species that are protected by statute or ordinance,
and that would require additional consultation with the
city if found onsite.
Question: Does the city agree that it is also important to
identify sensitive plant and tree species that are protected
by statute or ordinance, and that would require additional
consultation with the city if found onsite?
Comment acknowledged. The commenter’s recommended revision to
Mitigation Measure MM-BIO-1D is added to Chapter 4 of the Final EIR and is
included in the MMRP.
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Question: if the answer to the above question is yes, will
the city agree to the suggested language revisions or the
equivalent?
Question: if the answer to the above question is no, why
not?
B4-B-63 Page 3.3-48: Recommended Change) MM-BIO-E:
Preconstruction Surveys for Special-Status Wildlife: Within
one (1) week prior to initiating disturbance activities,
clearance surveys for special-status animal species shall be
performed by a qualified biologist(s) within the boundaries
of the future project disturbances. If any special-status
animals are found on the site, a qualified biologist(s) flag
the area for avoidance and discuss possible seasonal
avoidance measures with the developer. If avoidance is not
feasible, the Project Biologist, with a CDFG Scientific
Collection Permit shall relocate these species to suitable
habitats within surrounding open space areas that would
remain undisturbed, unless the biologist determines that
such relocation cannot reasonably be accomplished at
which point CDFG will be consulted regarding whether
relocation efforts should be terminated. Relocation
methods (e.g., trap and release) and receiver sites shall be
verified and approved by the CDFG prior to relocating any
animals.
There are circumstances, such as burrowing owl, where an
active nesting burrow can be seasonally avoided until a
more reasonable time period can be determined for the
species to be relocated and the burrow collapsed.
Question: will the final EIR include clarifying language such
as that suggested or its equivalent in the final EIR draft?
Comment acknowledged. The commenter’s recommended revision to
Mitigation Measure MM-BIO-1E is added to Chapter 4 of the Final EIR and is
included in the MMRP.
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If the answer to the above question is no, then why not?
B4-B-64 Page 3.3-50: Recommended Change) MM-BIO-1H:
Protection of Eagle Nests: No development or project
activities shall be permitted within one-half mile, if not in
line of site of a proposed activity, one mile if line of site of a
proposed activity of a historically active or determined
active golden eagle nest unless the planned activities are
sited in such a way that the activity has minimal potential
to cause abandonment of the nesting site, as determined
by a qualified biologist. 10 In addition, the eagle nest (if
active) shall be monitored by a biologist who is highly
familiar with the signs of eagle distress during the project
development activities. The monitoring shall continue until
the monitoring biologist is confident the nest will not be
disturbed. The monitoring biologist shall have the authority
to stop project activities as needed.
Question: were the most recent laws and regulations used
for this section? If so, please specify which ones were
used.
We believe the recommendation is to not have activity
within a mile of a nest that is determined active between
December-July. A half mile buffer is used for active nests
that are not in line of sight or have been determined by a
biologist (in consultation with CDFW) will not impact the
active nest.
Eagles are considered fully protected and there are no take
authorizations for this species.
Comment acknowledged. The commenter’s recommended revision to
Mitigation Measure MM-BIO-1H is added to Chapter 4 of the Final EIR and is
included in the MMRP.
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B4-B-65 Page 3.3-52: This statement is confusing and is
contradictory to the assumption of Impact 3.3-2 on page
3.3-51 that it is Less than Significant with Mitigation.
Comment acknowledged. The following sentence is added to Chapter 4 of the
Final EIR to clarify the statement: “Therefore, impacts to oak woodlands and
other native woodlands could be significant and unavoidable without
mitigation.” (Emphasis added.)
B4-B-66 Page 3.4-25: Recommended Change) In the event that
human remains or suspected human remains are identified,
the city shall comply with California law (Heath and Safety
Code § 7050.5; PRC §§ 5097.94, 5097.98, and 5097.99). The
area shall be flagged off and all construction activities
within 100 feet (30 meters) of the find shall immediately
cease. The Qualified Archaeologist shall be immediately
notified, and the Qualified Archaeologist shall examine the
find. If the Qualified Archaeologist determines that there
may be human remains, they shall immediately contact t he
Medical Examiner at the Los Angeles County Coroner’s
office. If the Medical Examiner believes the remains
are Native American, he/she shall notify the NAHC within
24 hours. If the remains are not believed to be Native
American, the appropriate local law enforcement agency
shall be notified. The NAHC shall immediately notify the
person it believes to be the most likely descendant (MLD) of
the remains, and the MLD has 48 hours of being granted
access to the site to visit the discovery and make
recommendations to the landowner or representative for
the respectful treatment or disposition of the human
remains and any associated grave goods. If the MLD does
not make recommendations within 48 hours of being
granted access to the site, the remains shall be rein terred in
the location they were discovered and the area of the
property shall be secured from further disturbance. If there
are disputes between the landowners and the MLD, the
NAHC shall mediate the dispute and attempt to find a
solution. If the mediation fails to provide measures
acceptable to the landowner, the landowner or their
The explanation for why 3.4-3 is less than significant, and thus no mitigation
measures are required, is provided in the paragraphs substantiating this finding.
To wit:
The treatment of human remains is regulated by California Health and
Safety Code Section 7050.5 and the treatment of Native American human
remains is further prescribed by Public Resources Code Section 5097.98.
These regulations are applicable to all projects within the Planning Area. While
the General Plan does not include any policies related to the treatment of
human remains, future development anticipated under the General Plan would
be required to comply with these regulations. Therefore, impacts associated
with the disturbance of human remains would be less than significant.
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representative shall reinter the remains and associated
grave goods and funerary objects in an area of the property
secure from further disturbance. The location of any
reburial of Native American human remains shall not be
disclosed to the public and shall not be governed by public
disclosure
requirements of the California Public Records Act, California
Government Code § 6250 et seq., unless otherwise required
by law. The Medical Examiner shall withhold public
disclosure of information related to such reburial pursuant
to the specific exemption set forth in California Government
Code §6254(r).
For Impact 3.4-3 there were no mitigation measures
offered.
Question: why was there no mitigation measure offered for
an inadvertent discovery of human remains?
This is generally not anticipated, and although it may be
not considered significant, there should be a measure in
place that a developer and the city should generally follow.
We provided an example of a MM that addressed
inadvertent discoveries
B4-B-67 Page 3.5-33: Construction emissions may be more
significant since the report admits it is a “conservative
assumption” based on “an expectation of a maximum of 10
percent of the total buildout area” would develop in a year
(3.5-28, 3.5-29)
It considers this impact as less than significant with no
mitigation. However, it is based on assumptions:
See responses to comments B4-A-13 and B4-A-14.
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3.5: “construction emissions were forecasted based on an
expectation of a maximum of 10 percent of the total build-
out area that could be potentially developed in any year.”
but also acknowledges that “it is likely that some projects
would extend for more than one year, and therefore,
would increase total project emissions” and so the
“analysis uses a conservative estimate of total project
emissions” (3.5-28- 3.5-29)
It also claims that “policies aimed at resource conservation
and VMT reduction would reduce overall GHG emissions
compared to existing conditions” (3.5-35).
Question: given that it is intended that “policies aimed at
resource conservation and VMT reduction would reduce
overall GHG emissions compared to existing conditions,”
then why are the related general plan policies for VMT are
not mandatory?
It also states the “Amount of oak woodland that would be
converted” or replaced are unknown, the ‘quantification of
emissions from conversion...was not included in the
emissions calculations.” The claim that the impact is less
than significant are based on unreliable assumptions. (3.5-
35)
Question: given that the “Amount of oak woodland that
would be converted” or replaced are unknown, the
‘quantification of emissions from conversion ...was not
included in the emissions calculations,” and since the
amount of oak woodland that would be converted or
replaced are unknown, then how can the claim be justified
that the impact is less than significant?
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Question: why were the reasons and justifications for the
less than significant claims not included in the DEIR
document?
The report does have a specific measure: “for every acre of
forest removed, an average of 0.85 MTCO2 sequestration is
lost”.
Question: how many acres of forest could be developed in
this plan? The amount of sequestration that could be lost
can be calculated and included to fully evaluate its impact
on GHG/climate change.
B4-B-68 Page 3.5-33: Question: given that the “Amount of oak
woodland that would be converted” or replaced are
unknown, the ‘quantification of emissions from conversion
...was not included in the emissions calculations,” and since
the amount of oak woodland that would be conv erted or
replaced are unknown, then how can the claim be justified
that the impact is less than significant?
See response to comment B4-A-14.
B4-B-69 Page 3.5-33: Question: why were the reasons and
justifications for the less than significant claims not
included in the DEIR document?
The report does have a specific measure: “for every acre of
forest removed, an average of 0.85 MTCO2 sequestration is
lost”.
See response to comment B4-A-14.
B4-B-70 Page 3.5-33: Question: how many acres of forest could be
developed in this plan? The amount of sequestration that
could be lost can be calculated and included to fully
evaluate its impact on GHG/climate change.
See response to comment B4-A-14.
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B4-B-71 Page 3.5-39: Several policies included in the CAP are no
longer mandatory due to revisions to the General Plan
language in the middle of the comment period.
Question: How are the assumed reductions in MTCO2 still
valid?
See responses to comments B2-4 and B4-B-40. Revisions to the General Plan
policy language do not change the intent of these policies or diminish their
applicability in the Climate Action Plan modified emissions forecast. The Climate
Action Plan uses the methodology outlined in the California Air Pollution Control
Officers Association’s (CAPCOA) Quantifying Greenhouse Gas Mitigation
Measures report to quantify emissions reductions from the General P lan
policies. For each category of policies, calculation of emissions reductions
assumed the minimum percentage reduction in the range provided by CAPCOA.
In multiple cases, the General Plan policies were not assumed to be mandatory
or universally implemented. Therefore, the calculated reductions in MTCO2e are
still valid and revisions to the policies do not have any material effect on
conclusions made in the CAP and Chapter 3.5.
B4-B-72 Page 3-5-39: Question: What measures will be added to
the CAP to enable the expected streamlined environmental
review under CEQA?
The CAP concludes that for projects and actions that are consistent with the
General Plan, no further GHG analysis would be required, and thus the time
required to prepare required CEQA documents would potentially be shortened.
B4-B-73 Page 3.5-28: Global comment: This document should
follow the 2019 CEQA Guidelines. Greenhouse Gas now
only has two criteria under Appendix G. The other two are
now covered under Section VI Energy.
Question: Why does the EIR not account for the recent
change to the CEQA 2019 Statutes and Guidelines? How
will this be addressed?
See Response Comment B4-B-18. Chapter 3.5: Energy, Climate Change, and
Greenhouse Gases consolidates the Greenhouse Gas and Energy criteria in the
CEQA 2019 Statutes and Guidelines as analysis of the topics is based on similar
environmental settings, regulations, and data. Criteria 3.5-3 and 3.5-4 directly
correspond to Section VI Energy Criteria A and B, respectively. Criteria 3.5-1 and
3.5-2 directly correspond to Section VIII Greenhouse Gas Emissions Criteria A
and B, respectively. The language of the criteria is identical to that most recently
updated in December 2018.
B4-B-74 Page 3.5-38: City of Diamond Bar, should adopt similar
policies as the City of Long Beach regarding LEED building
policies to reduce energy consumption and GHG emissions.
Although, it may be less than significant impacts the city
should provide policies or mitigation measures to further
reduce its carbon footprint and energy efficiency, or
unnecessary consumption of energy resources. See link
below:
See response to Comment B4-A-5.
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http://www.longbeach.gov/globalassets/sustainability/me
dia-library/documents/urban-living/builidings-and-
neighborhoods/greenbuildingpolicy
Question: Will the city plan to adopt policies as discussed
above which are similar to those adopted by the city of
Long Beach?
B4-B-75 Page 3.5-38: We like the policies that the City of Long
Beach described with some goals that they would t ry and
achieve.
http://www.longbeach.gov/globalassets/sustainability/me
dia-library/documents/nature-initiatives/action-plan/scap-
final
Comment acknowledged.
B4-B-76 A land use plan element should require that new
commercial, mixed use or transit oriented developments
include the design and installation of electrical
infrastructure to promote the installation for current or
future EV charging infrastructure.
Current general plan language changes have made those
policies optional. How will the city be able to achieve the
expected reduction in GHG and meet its emissions targets
for automobiles?
Question: Does the city plan to revise those policies and
make them mandatory?
See responses to Comments B4-B-10 and B4-B-50.
B4-B-77 Page 3.10-24: There is no discussion under Criteria 1 in
regard to Sensitive Receptors to noise, such as schools.
Sensitive receptors should be included and identified under
this criteria. And MM should be suggested that would limit
activities during these hours, or use of noise attenuation
See responses to Comments B4-B-33, B4-B-34 and B4-B-35.
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measures such as noise blankets or walls to temporarily
reduce decibel levels in proximity to these sensitive
receptors.
B4-B-78 Page 3.11-29: Question: what elements exist in the Parks
and Recreation Master Plan that address the potential
mitigation to increase the availability of parks?
Question: Are there open spaces within the city that have
been identified?
The Parks and Recreation Master Plan is a public document and is available for
anyone to review. The City has and continues to seek opportunities to acquire
land to add to its parkland inventory. The most recent acquisition was the
purchase of 2.83 acres at 22555 Sunset Crossing Road from the YMCA.
This comment does not address the adequacy of the adequacy of the Draft EIR;
therefore, no further response is required.
B4-B-79 Page 3.11-29: According to LU-P-54, then City of Diamond
Bar should consider other public uses for public agency
lands. Such as the County owned Golf Course.
Question: How does the Core Community Overlay address
recreation opportunities sufficiently such that the City can
be in alignment with the Quimby Act and meet its ratio of 5
acres per 1000 residents?
Should Los Angeles County ever dispose of the golf course, Draft General Plan
Policy LU-P-45 requires that approximately 100 acres be set aside for parkland.
A repurposed golf course could thus serve 20,000 residents, and —based on the
2016 City population estimate of 57,081--raise the Citywide parkland ratio from
2.6 acres per 1,000 residents to 4.4 acres per 1,000 residents.
B4-B-80 Page 3.11-44: This EIR identified several potential new
trails: Tonner Canyon, Crooked Creek etc.
We support the development of trails and access to views
of the open space in the SOI. We would just like
consideration and mitigation measures to address any
potential impacts if and when those trails are developed.
Question: Why was there no discussion or consideration of
environmental impacts under this Criteria for the potential
new trails?
As stated under Impact 3.11-3, new park developments would be subject to
CEQA. It is further acknowledged that planned expansions or modifications to
trails will also be subject to CEQA. See also response to Comment B4-B-57 and
B4-B-61.
B4-B-81 Figure 4.2-2 Alternative 1) In the Transit Oriented Mixed
Use Area it shows both mobile home parks included. The
Alternative 1 is expressly defined to include the delineated 105-acre boundary
for the TOD Mixed Use district as depicted in Figure 4.2-2.
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newly revised area ends at the east end of the western
mobile home park.
Please revise the map to reflect the currently correct size.
B4-B-82 Figure 4.2-3 Alternative 2) In the Transit Oriented Mixed
Use Area it shows both mobile home parks included. The
newly revised area ends at the east end of the western
mobile home park.
Please revise the map to reflect the currently correct size.
Alternative 2 is expressly defined to include the delineated 105-acre boundary
for the TOD Mixed Use district as depicted in Figure 4.2-3.
B4-B-83 Alternatives should also include existing Town Center at
Diamond Bar Blvd and Grand Ave with the new General
Plan and Climate Action Plan. It is a reasonable alternative
that was not described.
Question: Given that Alternative 2 is not a viable
alternative, why were other alternatives, such as the
location mentioned above considered as alternatives in the
DEIR?
See responses to Comments B4-B-6 and B4-B-7.
B4-B-84 The difference between the Proposed Project and
Alternative 1 is a Core Community Overlay, which if
developed, would result in an undetermined
environmental impact to offset the loss of the
existing County Golf Course--as would Alt 2. This impact,
which cannot be adequately quantified at this time, would
in fact have a potentially and significant environmental
impact. Therefore, it is not clear how the Proposed
Alternative is similar in impact to Alt 1. If the Core
Community Overlay has to be determined at a later time,
and may be determined infeasible due to environmental
considerations, then you have currently only proposed two
alternatives in addition to the No Project Alternative.
The creation of a Town Center is a cornerstone of the Draft General Plan’s
Community Vision and comprises one of the Draft Gen eral Plan’s seven Guiding
Principles. A Town Center is therefore a project objective that must be
accounted for in the Alternatives Analysis. As a predominantly built-out
community, there are very few opportunities to locate a Town Center. As
stated in response to Comment B4-B-6, the prospect of locating the Town
Center at the intersection of Grand Avenue and Diamond Bar Boulevard was
rejected as infeasible. CEQA Guidelines Section 15126.6 requires an EIR to
consider “a reasonable range of alternatives” to a project. Alternatives 1 and 2
satisfy that requirement given to accommodate a project objective as specific as
creating a Town Center. The approach cities often take in defining general plan
EIR alternatives is to consider lower and higher density/intensity build-out
scenarios: this approach invariably leads to the perfunctory conclusion that a
lower-density alternative would fail to meet RHNA requirements imposed on all
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Question: Given the reliance of Alternative 2 on the
Community Core Overlay being invoked, and given the fact
that the Golf Course is indeed in operation, and given the
fact that it is “infeasible,” as defined by CEQA Guideline
§15364, at this time to determine the complete extent of
environmental impacts and mitigations necessary to have
obtained the Golf Course property, why was Alternative 2
even suggested as a viable alternative in the DEIR?
California cities; and a higher-density alternative would result in more severe
environmental impacts across a range of environmental categories. In light of
the factors considered above, the Diamond Bar General Plan 2040/CAP 2040
DEIR provides an appropriate and reasonable range of alternatives to consider.
B5 CALIFORNIA WILDLIFE FOUNDATION/CALIFORNIA OAKS PROGRAM
B5-1 October 31, 2019
Grace S. Lee, Senior Planner
City of Diamond Bar, Planning Division
21810 Copley Drive
Diamond Bar, CA 91765
Transmitted via email: glee@diamondbarca.gov
Re: Draft Environmental Impact Report, City of Diamond
Bar General Plan 2040, and Climate Action Plan, SCH#
2018051066
Dear Ms. Lee:
This comment is the salutation of the letter. It does not address the adequacy of
the Draft EIR; therefore, no further response is required.
B5-2 The California Oaks program of California Wildlife
Foundation (CWF/CO) works to conserve oak ecosystems
because of their critical role in sequestering carbon,
maintaining healthy watersheds, providing habitat, and
sustaining cultural values.
Comment acknowledged. See responses to comments B5-3 through B5-8 below.
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CWF/CO has reviewed the City of Diamond Bar General
Plan 2040, Climate Action Plan, and the environmental
analysis presented in the Draft Environmental Impact
Report (DEIR). Comments pertain to mapping of biological
resources, fire hazards, greenhouse gas and air quality
impacts associated with the implementation of the General
Plan, and the city’s tree ordinance. Additionally, CWF/CO
offers that the language throughout the plan about the
importance of the natural resources is simply aspirational
absent strong measures combined with enforcement and
monitoring.
B5-3 Mapping data for biological resources: In the letter to the
City of Diamond Bar dated July 3, 2018 CWF/CO stated:
“We have also been informed that the habitat mapping
used in the General Plan materials do not accurately
represent the city’s oak resources.” Other letters also
addressed this issue, and the letter from Hills For Everyone
suggested that the city utilize more current mapping data.
Diamond Bar citizens continue to express concern that the
mapping remains inadequate. CWF/CO understands that
Hamilton Biological, Inc. prepared a biological resources
report in February 2019 to correct the deficiencies. The
delivery of the Hamilton report may have been after the
comment period closed. That said, CWF/CO notes the
caution in the DEIR on pages 3.3-5 and 3.36, which
indicates a need for finer-scale analysis of the mapped
vegetation (emphasis added with boldface text):
As with the native oak and walnut woodlands, there can be
considerable overlap and mixing of shrubland and scrub
alliances, which can lead to misinterpretations of the
alliance type when viewed from a distance or in aerial
photography, particularly in the summer when many scrub
species are deciduous. For this reason, the mapping of
See response to comment B3-9.
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these alliances and their mixtures in Figure 3.3-1 should
be considered to be subject to sitespecific investigations.
As noted on page 2 of Appendix A of the biological
resources report: “Mr. Hamilton conducted reconnaissance
field surveys on January 4 and 8, and February 4 and 8,
2019, to field-check the mapping and to observe the
existing conditions throughout most of Diamond Bar.”
B5-4 Fire Hazards: The section, Wildfire Management
Strategies, on page 7-16 of the draft General Plan discusses
approaches for mitigating fire risk:
As the State prepares for more such incidents as the
wildland-urban interface (WUI) continues to expand and
changes in climate patterns become more apparent,
wildfire risk management at the local level will become
increasingly important. Strategies tend to cluster around
two main approaches: maintaining defensible space
around structures, and ensuring that structures are
resistant to fire.
CWF/CO recommends the City of Diamond Bar restrict
development in areas designated by CAL FIRE to pose very
high or extreme fire threat as detailed in Figure 7 -5 on
page 718 and very high fire hazard severity zones as
detailed in Figure 7-6 on page 7-19. Such restrictions would
enhance safety and also conserve financial and natural
resources. At the very least, CFW/CO urges the City of
Diamond Bar to promulgate citywide fire risk disclosure
requirements for housing developments. Amador County
building code requires the county to make information
available to project applicants and real estate agents on
the risks of wildland fire, available levels of fire and
emergency response, and wildland fire prevention
methods; and to provide that same information when
Comment acknowledged.
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property changes hands in areas designated as high and
very high fire severity. That information is posted on the
county’s website.
B5-5 CWF/CO commends the City of Diamond Bar for the
language in PS-P-21 presented on page 3.11-39 of the DEIR,
which is protective of natural vegetation. As stated above,
a prohibition of development in these regions would result
in further protections. Greater specificity is needed in the
language below to detail how natural ecosystems will be
protected:
Collaborate with the County of Los Angeles Fire
Department to ensure that properties in and adjacent to
High or Very High Fire Hazard Severity Zones as indicated in
Figure 7-6 are adequately protected from wildland fire
hazards in a manner that minimizes the destruction of
natural vegetation and ecosystems through inspection and
enforcement. Update Figure 7-6 as new information
becomes available from CAL FIRE.
Comment acknowledged. Revisions to draft policy language is not within the
scope of the Final EIR.
B5-6 Greenhouse gas impacts: Page 1-6 of the Climate Action
Plan recognizes the greenhouse gas (GHG) impacts of the
conversion of oak woodlands and other natural
environments that sequester carbon (boldface text used
for emphasis):
California’s oak woodlands act as carbon sinks, storing an
estimated 675 million metric tons of carbon dioxide
(MTCO2e). Riparian habitats and wetlands also act as
climate sinks and are beneficial to ecological adaptation to
climate change. Destruction of these habitats, both
through land use decisions and the consequences of
intensifying climate change, has the potential to release a
significant amount of greenhouse gases. The Diamond Bar
General Plan update includes multiple policies aimed at
preserving open space and riparian habitat to encourage
the health of the City’s biological resources, particularly
See response to comment B4-A-14. The General Plan does not propose the
conversion of any oak woodlands, with the exception of the Golf Course, which
would be subject to environmental review under a later Master Plan.
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oak and walnut woodlands, and applies land use
designations that minimize impacts of development on
these resources.
California law requires the assessment of GHG impacts of
proposed oak removals, yet Appendix D does not include
such calculations. California Environmental Quality Act §
15364.5 states that “Greenhouse gas” or “greenhouse
gases” includes but is not limited to: carbon dioxide (CO2),
methane (CH4), nitrous oxide (N2O), hydrofluorocarbons,
perfluorocarbons and sulfur hexafluoride. California’s
Senate Bill 1383 (2016) designated methane, black carbon
and hydrofluorocarbon short-lived climate pollutants.
Upon the disposal of impacted vegetation, the
decomposition of biomass results in CO2 and CH4
emissions, and the combustion of biomass does in all cases
result in CO2, CH4, N2O, and black carbon (Decomposition:
"Anaerobic digestion, chemical process in which organic
matter is broken down by). CEQA does not differentiate
between anthropogenic and biogenic GHG emissions ("...
the combustion of biomass does in all cases result in net
additions of CH4 and N2O to the atmosphere, and
therefore emissions of these two greenhouse gases as a
result of biomass combustion should be accounted for in
emission inventories under Scope 1" (at p. 11). World
Resources Institute/World Business
Council for Sustainable Development (2005).). The
following 2009 Natural Resources Agency response to the
California Wastewater Climate Change Group proves the
point:
Response 95-1: “Regarding the comment that the
Guidelines should distinguish between anthropogenic and
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biogenic carbon dioxide emissions, the Natural Resources
Agency notes that SB 97 did not distinguish between the
sources of greenhouse gas emissions. Thus, it would not be
appropriate for the Natural Resources Agency to treat the
different categories of emissions differently absent a
legislative intent that the Guidelines do so. Neither AB 32
nor the Air Resources Board’s Scoping Plan distinguishes
between biogenic and anthropogenic sources of
greenhouse gas emissions. On the contrary, the Scoping
Plan identifies methane from, among other sources,
organic wastes decomposing in landfills as a source of
emissions that should be controlled. (Scoping Plan, pages
62-63).”
The total biomass weight of the impacted
overstory/understory vegetation must be known and the
means of biomass disposal identified to accurately and fully
account for natural land conversion GHG emissions
(EPA/USDA FS, 2015. Forest Biomass Components:
https://cfpub.epa.gov/roe/indicator.cfm?i=86.). The
following questions must be addressed in order for the
environmental documentation to be complete:
• What is the estimated total biomass weight of the
impacted overstory and understory vegetation by
2020, 2030 and 2050?
• Due to the presumed transport of disposed
biomass off-site, what are the estimated CO2,
CH4, N2O, and black carbon emissions?
Lastly, on page 8-23 of General Plan, measure CHS-G-11
(boldface text added for emphasis) is to: “Undertake
initiatives to enhance sustainability by reducing the
community’s greenhouse gas (GHG) emissions, protecting
natural open spaces which provide CO2 sequestration ,
and fostering green development patterns, buildings, sites,
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and landscapes.” The City of Diamond Bar needs to add
clear language to the General Plan to articulate how
natural open space protections will be achieved, enforced,
and monitored.
B5-7 Tree Ordinance: The July 2018 letter by CWF/CO urged
“the City of Diamond Bar to strengthen the tree ordinance
by applying it to parcels of one-half acre and smaller, and
to extend individual tree protections to trees smaller than
eight inches diameter at breastheight (DBH).” The DEIR
discusses the tree ordinance in the summary of Areas of
Controversy on page ES-7:
Many of the comments addressed impacts to important
biological resources, particularly oak woodlands.
Inadequacy of the City of Diamond Bar’s existing tree
ordinance and the Existing Conditions Report led to
community concern over the protection of open space and
special-status species. Anticipated development under the
Proposed Project could reduce existing open space and
viable habitat.
Unfortunately, the proposed Resource Conservation policy
(RC-P-10) for the impact does not include an improved tree
ordinance:
Require new development to preserve mature native trees
including oak and walnut, and trees of significant cultural
or historical value such as sycamore and arroyo willow,
etc., as set forth under the Diamond Bar Tree Preservation
and Protection Ordinance. Review the ordinance
periodically and update it as necessary to reflect current
best practices.
See response to comment A3-12.
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Lastly, the DEIR Mitigation Measure Bio-4 presented in
table ES-4 on page ES-29 of the DEIR states that: “In the
event a future project would result in the loss of an oak
woodland, the project shall be subject to the mitigation
requirements set forth in the Los Angeles County Oak
Woodland Conservation Management Plan Guide.”
Restoration ratios detailed in the table differ (and are
weaker in some cases) from those in the City of Diamond
Bar’s tree ordinance section 22.38.130. For example, the
county restoration ratio may be 1:1 in certain
circumstances whereas the City of Diamond Bar’s tree
replacement/relocation standards state: “Replacement
trees shall be planted at a minimum 2:1 ratio for residential
properties less than 20,000 square feet. Residential parcels
greater than 20,000 square feet and commercial and
industrial properties shall be planted at a minimum 3:1
ratio…” The City of Diamond Bar needs to clarify how the
tree ordinance and mitigation requirements set forth in the
Los Angeles County Oak Woodland Conservation
Management Plan Guide are to be reconciled.
B5-8 Air Quality: Section 5.6 of the General Plan discusses the
South Coast Air Basin’s poor air quality. American Lung
Association assigned the grade of F to Los Angeles County’s
air for ozone and particle pollution (24-hour and annual)
(see http://www.lung.org/ourinitiatives/healthy-
air/sota/city-rankings/states/california/los-angeles.html).
Resource Conservation-Policy-29 presented on page 5-41
of the General Plan is to: “Conserve natural open spaces,
biological resources, and vegetation, recognizing the role of
these resources in the reduction and mitigation of air
pollution impacts, and the promotion of CO2
sequestration.” However, as stated in the introductory
comments, without specific language and clear protections,
This comment recommends revision to a General Plan policy. It does not
address the adequacy of the Draft EIR; therefore, no further response is
required.
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there is no reason to believe Diamond Bar’s natural
resource values will be upheld through the implementation
of the General Plan.
B5-9 Thank you for your consideration of these comments.
CWF/CO is available, should additional information be
needed.
Sincerely,
Janet Cobb
Executive Officer
Angela Moskow
Manager, California Oaks Coalition
This comment is the closing of the letter. It does not address the adequacy of
the Draft EIR; therefore, no further response is required.
B6 DIAMOND BAR – POMONA VALLEY SIERRA CLUB TASK FORCE | ANGELES CHAPTER
B6-1 Diamond Bar – Pomona Valley Sierra Club Task Force
Angeles Chapter
October 31, 2019
TO: Ms. Grace Lee, Senior Planner, City of Diamond Bar
[delivered electronically]
CC: City of Diamond Bar, Community Development
Director, Mr. Greg Gubman
RE: City of Diamond Bar, General Plan, DEIR Comments
Dear Ms. Lee,
This comment is the salutation of the letter. It does not address the adequacy of
the Draft EIR; therefore, no further response is required.
B6-2 The purpose and goals of the Diamond Bar – Pomona
Valley Sierra Club Task Force, Angeles Chapter, are
dedicated to local conservation: to educate environmental
literacy to all, especially the youth; to explore, enjoy and
protect local wildlife habitats, to advocate biodiversity,
Comment acknowledged.
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natural open spaces and sustainable communities. Our
group activities and contributions are locally focused.
We are grateful for the opportunity to comment on the
General Plan 2040/DEIR. We think forward-thinking,
community-based partnerships are foundational to guard
against error and to reach for extraordinary levels of
quality and economic productivity in conservation
planning.
B6-3 Here are our concerns, which also include a personal point
of input:
1. Wildlife Habitat and Circulation: The Resource
Conservation element and DEIR fails to regard or
thoroughly explain wildlife circulation throughout the mid
and northern part of the city. Example: my own property
which is mapped as oak woodland on DEIR figure 5.2 is
partially correct (because the coastal scrub is missing) has
been a consistent “wildlife corridor” these 30 years past (or
more?). There is an established “game trail” where we
routinely observe deer families arrive from traversing the
native green belt tracing throughout the Diamond Ridge
neighborhood near Pantera Park. The Hamilton report
accurately depicts this region as area #3, in the natural
communities map. Therefore, Hamilton’s approach to
mapping natural communities according to their existence
rather than human boundaries is correct. Please explain
what scientific basis the city claims wildlife circulation only
happens at the Puente Chino Hills Wildlife Corridor? Recall,
2013 Diamond Bar city hall sighted a mountain lion, which
may have arrived from Upper Tonner Canyon/Tres
Hermanos or Powder Canyon. Here are pictures of my own
property, north face ridgeline, oak/walnut, sage scrub
habitat.
The movement and exchange expected to occur is implied on the map provided
in Figure 3.3-3 of the DEIR. As shown, the map clearly shows the movement
corridor as progressing north through Tonner Canyon. Insofar as then City has
no control of land uses in its SOI, but the importance of protecting movement
corridors through the area is identified in the DEIR, the General Plan update
DEIR established the importance to conserve and protect these corridors when
designing future developments. See also response to comment B3-14.
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[Photos]
B6-4 2. The DEIR city environmental location description is
inadequate. There appears to be no geomorphic, geological
or floristic references to where the city of Diamond Bar is.
For example, Dibblee maps indicate the city of Diamond
Bar is located in: Brea Canyon, in the Puente Hills, which
are at the tip of the Peninsular Ranges, in the Southern
California Mountains & Valleys Ecoregion. These terms
hold meaningful descriptions by which to assess, soils,
native plant communities, climate patterns. How else can
specific ecological features and conditions be discovered or
understood? Will the city of Diamond Bar update the
environmental location of the city in all general plan
documents?
The City believes the description of the Physical Setting of the Stud y Area
provided on page 3.3-3 to be adequate for the concerned reader.
B6-5 3. Geologic Constraints: The DEIR omits describing geologic
constraints of the city. Example: The City’s landscape
comprises a system of canyons, streams, floodplains,
ridges, and hillsides. Prominent knolls and ridges reach
elevations of 1,300 to 1,400 feet above sea level. Most
hillsides contain slopes in excess of 25%. These hillside
areas are underlain by bedrock of the Puente Formation.
The rocks of this formation are folded and dip between 10
and 20 degrees horizontal. Locally, beds of Puente
Formation dip as steep as 45 to 60 degrees. The folded
nature of these rocks combined with the steepness of the
terrain makes Diamond Bar one of the most landslide-
prone areas in Southern California. I cannot located
descriptions which help us to understand safety risk, such
as landslide potential.
The geologic setting of the Planning Area is described in the Environmental
Setting of Chapter 3.6 (pages 3.6-2 through 3.6-5) and depicted in Figures 3.6-1
through 3.6-4. The geologic constraints are further addressed in the impact
analysis on pages 3.6-26 through 3.6-36. The City believes this description to be
sufficient for the purposes of this analysis.
B6-6 4. Is it meaningful to include the California Deep Landslide
Inventory? If not, why not? Again, isn’t this relevant to
safety concerns and mitigation solutions?
Landslide-susceptible areas within the Planning Area are discussed on page 3.6-
4 and depicted in Figure 3.6-1. The City believes this description to be sufficient
for the purposes of this analysis.
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B6-7 5. Proposal for new city tree codes including
recommendations for oak woodland protection, walnut
woodland protections and productive measures to improve
the city urban canopy. Existing codes are sorely outdated.
Based on current science of natural communities and
alliances, per the California Vegetation Manual, Hamilton
Biologic analyzed in February 2019, a new proposed tree
code. Attached. A year previous, a red line draft of the
previous tree codes was performed by State Urban
Forester, John Melvin’s recommended local urban forester,
David Haas to assist me in analyzing and
correcting/improving the city’s existing tree codes.
Attached. I respectfully request the city review this
material to achieve updated tree codes to serve the quality
of life in the City of Diamond Bar; and to preserve best
practice.
See response to comment A3-12.
B6-8 Respectfully,
C. Robin Smith, Chair
CC: Sierra Club Angeles Chapter, Senior Chapter Director,
George Watland
DBPV Sierra Club Task Force, Vice Chair, David Warren
Sierra Club, Angeles Chapter, Conservation Chair, Angelica
Gonzales
Sierra Club, San Gabriel Valley Task Force, Chair, Joan Licari
References:
Dibblee Maps, Peninsular Ranges, Ecoregion map
This comment is the closing of the letter. It does not address the adequacy of
the Draft EIR; therefore, no further response is required.
B6-9 [Biological Resources Report, City of Diamond Bar] Attachment provided in support of comments B6-3 and B6-4, addressed above.
B6-10 [City of Diamond Bar, Biological Resources Natural
Communities]
Attachment provided in support of comments B6-3 and B6-4, addressed above.
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B6-11 [Chapter 22.38 – Tree Preservation and Protection Redline
Draft April 2016, input from Cynthia Smith]
Attachment provided in support of comment B6-7, addressed above.
B6-12 [Proposed Amendments to the Diamond Bar Tree
Protection Ordinance, Hamilton Biological (2/20/19)]
Attachment provided in support of comment B6-7, addressed above.
B6-13 [Geologic Map of the San Dimas and Ontario Quadrangles] Attachment provided in support of comments B6-5 and B6-6, addressed above.
B6-14 [Geologic Map of the Whittier and La Habra Quadrangles] Attachment provided in support of comments B6-5 and B6-6, addressed above.
B6-15 [Geologic Map of the Yorba Linda and Prado Dam
Quadrangles]
Attachment provided in support of comments B6-5 and B6-6, addressed above.
B6-16 [Ecological Sections of California] Attachment provided in support of comments B6-3 and B6-4, addressed above.
B7 DIEGO TAMAYO
B7-1 Oct. 31, 2019
Comments for the City of Diamond Bar General Plan 2040,
DEIR
To: Grace Lee, City Senior Planner
Dear Ms. Lee:
This comment is the salutation of the letter. It does not address the adequacy of
the Draft EIR; therefore, no further response is required.
B7-2 It is good to see the City of Diamond Bar finally
acknowledge in the general plan and EIR, the rare and
sensitive species and natural communities, we are
privileged to have here.
The Diamond Bar – Pomona Valley Sierra Club is a local
conservation group. Our work involves exploring, enjoying
and protecting wildlife habitats and ecosystems in our city
and the surrounding areas. Our “community science”
activities have come up with some exciting findings.
Comment acknowledged. See responses to comments B7-3 through B7-14
below.
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Since the Diamond Bar – Pomona Valley Sierra Club has
been working on an on-going “Diamond Bar Natural
History” project these past three years, I submit some of
our findings – which has been and is being mapped on
iNaturalist, eBird and the CNDDB. We are also
communicating with the Los Angeles Natural History
Museum staff in assisting to map our findings of the rare
and critically imperiled Los Angeles County Shouldband
snail, which has been found distributed throughout
Diamond Bar.
My overall comments about the draft environmental
report are concerned with the missing bits of important
biotic information, as well as the incomplete or incorrect
information in mitigation plans or reported species.
B7-3 Here is a list of my questions and concerns:
Cultural Findings, page 45-52, Resource Conservation Chpt.
5
1. The DEIR does not mention the (approximate) 40 boxes
of stone artifacts recovered at the Pulte Home
development project (gated community, located off Crest
View and Diamond Bar Blvd.) in 2006. Our group spoke
with Dr. Beardsley and curator, Anne Collier at University
of La Verne, where the findings are stored, in 2017.
Q: Why are these findings missing from pg. 49’s chart? Will
the City of Diamond Bar correct this omission?
This particular resource is not missing and is listed as P-19-002805 in Table 3.4-2
of the Draft EIR and Table 5-4 of the Resource Conservation Chapter of the
General Plan. The California Department of Parks and Recreation site form for
this resource obtained from the South Central Coastal Information Center
(SCCIC) in 2016 indicates that this particular resource was initially encountered
immediately prior to the start of construction of the Pulte Homes development
in the spring of 2000. Any additional information regarding the contents and
condition of this resource have not been submitted to the SCCIC as of 2016.
B7-4 What will the city do to restore these findings to the city’s
historical society and rightly honor the Kizh Nation?
This action is not included in the scope of the General Plan of the Draft EIR. This
comment does not address the adequacy of the Draft EIR; therefore, no further
response is required.
B7-5 2. The south end of the city at the “Cathay View”
development, a registered “sacred Kizh oak woodland”
The resource is not included in the chart because the information to populat e
the chart was acquired from the South Central Coastal Information and
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land was officially registered June 13, 2017: N-CAN 33. Q:
Why is this listing missing from the Cultural Resources,
Resource Conservation, chapter 5, page 49 chart?
California Native American Heritage Commission (NAHC) in 2016, prior to the
registration of that particular resource in 2017. An updated Sacred Lands
Search from the NAHC in July 2019 did identify this resource within the NAHC
database. The identification of this resource does not impact the conclusions of
the analysis or the mitigation measures in the Draft EIR or General Plan. Table
3.4-2 in the Draft EIR has been revised in Chapter 4 of this document to include
this resource. Table 5-4 in Chapter 5: Resource Conservation has been revised in
the Public Hearing Draft General Plan to include this resource.
B7-6 Vegetation Communities: Figure 5.2
3. Oak woodland natural communities are under reported
in the DEIR habitat map. At least the designation ought to
be: southern oak/walnut woodland. California walnut trees
are not dominant throughout the city. Please view my
pictures of Steep Canyon, Sycamore Canyon and show me
where the walnut trees are the dominant species. (posted
in the following natural history draft report I submit here.)
See response to comment B3-9.
B7-7 4. Opuntia litoralis, cactus scrub is not named in the DEIR,
though it is a dedicated alliance in the Manuel of California
Vegetation, second edition, Sawyer, Keeler -Wolf,
Evans.
https://calscape.org/Opuntia-littoralis-(Coast-Prickly-
Pear)?srchcr=sc5708872f8cdd6
Diamond Bar has dominant patches of this natural
community distributed throughout onDEIR? Will the city
correct the omission?
Cactus scrub is listed as one of the native shrublands and scrub alliances fo und
in the study boundaries of page 3.3-5 of the DEIR. It is also listed as a very
highly sensitive natural community in Table 3.3-2 on page 3.3-12 of the DEIR.
And, it is referenced as habitat for coastal cactus wren in Table 3.3 -4 on page
3.3-27.
B7-8 5. Sycamore Canyon Park is designated by the USGS as a
“sycamore riparian” habitat due to Diamond Bar Creek
passing through it from Steep Canyon. Q: Why is Sycamore
Canyon Park colored yellow/walnut woodland, with non-
native grasses? See the picture attached and explain how
the city came up with such an incorrect report.
See response to comment B3-9, particularly the statement about the need for
site-specific confirmation of natural communities mapping.
B7-9 Wildlife Circulation/Corridor Activity The information provided in the comment is acknowledged and does not
conflict with the findings of the Draft EIR. See response to comment B3-15.
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Chapter 3: Responses to Comments
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Comment ID Comment Response
6. Deer, coyote, bobcat and cougar have been regularly
sighted, circulating throughout Diamond Bar. The northern
areas (see Hamilton Report map, area #3 especially.)
Mountain lion was encountered at city hall in 2013, routine
resident sightings in The DB Country Estates, and a recent
report from a hiker near Tres Hermanos/Phillips Ranch
area, 2019. Residents in area #3, Hamilton report map,
have observed regular visits of deer families, circulating
throughout this green area, comprised of grassland,
oak/walnut woodland and coastal scrub. The deer travel in
and round Pantera Park, Steep Canyon, Sycamore Canyon
and Summitridge trail, and frequently observed browsing
on the side of Diamond Bar Blvd., near Crest View and Gold
Rush avenues. (see photos in my gallery).
B7-10 Q: What support will the city lend to the wildlife circulation
WITHIN the city neighborhoods? Q: Why is there no
mention of wildlife circulation in the mid-northern
portions? Has the city considered the Hamilton report’s
wildlife corridor map?
See response to comment B3-15. See also the discussion of the recognized
importance of movement and the discussion of related General Plan policies
and Mitigation Measures on pages 3.3-59 through 3.3-62.
B7-11 7. Sensitive species like California Gnatcatcher, burrowing
owl, golden eagle, red rattlesnake, cactus wren are
observed throughout the trail and wildland areas in the
city. I have personally observed the gnatcatcher in Steep
Canyon area (see pic.) Hikers and residents regularly
contact our Sierra Club with their pictures and reports. One
hiker submitted a photo of a burrowing owl located near a
Diamond Bar trail. (see pic.)
Of the species listed in the comment three are noted as observed/recorded in
the study area (see Table 3.3-4 in the DEIR. The fourth species listed, as well as
a number of others are indicated to have moderate to high potentials to occur
for the purpose of future project-related surveys.
B7-12 Q: Why is the information incomplete in the Resource
Conservation and DEIR document? What effort will the city
do to officially report the presence of these species to state
conservation trustee agencies like the CDFW and USFWS?
Through the CEQA environmental review process all MNDs and EIRs are subject
to public review. In particular, public agencies, including CDFW and USFWS are
directly mailed copies of these documents by the State Clearinghouse. As such,
full disclosure of the presence of special-status species on a project site in
inherent to the review process.
B7-13 Q: Why does Figure 5.2 use the term “vegetation
communities”? The official term used by the California
This correction is made in Chapter 4 of the Final EIR and in the Public Hearing
Draft General Plan.
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Chapter 3: Responses to Comments
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Comment ID Comment Response
Vegetation text book, is “natural communities”, indicating
natural ecosystems – not supported by man-made
interventions like automated irrigation, fertilizer,
pesticides, tilling or discing. Q: Will the city correct the
misleading term, “vegetation” communities?
B7-14 Specific Details and a Program EIR
In summary, the general plan and DEIR explains it is a
general assessment and not specific, promising that each
future development project will examine biological
resources in detail. Yet, it also mentions during the detailed
survey of a project, it is allowed to depend on the general
plan/EIR. Does this mean there is a loop hole in performing
CDFW protocol surveys for projects in the “wild edge” or
other sensitive ecological areas? How will mitigation
monitoring be handled? Will the Public be apprised of who
are the monitors and how monitoring procedures are
implemented?
Q: How can accurate surveys and conservation be
accomplished of the DEIR is vague and general, then
promises specific assessments be accomplished in future
developments if at the core, there are no specific
declarations like “Diamond Bar Creek traversing Sycamore
Canyon Park”?
In using terminology that implies the General Plan EIR will be used to guide
future project-specific surveys, no loopholes are created. It simply means that
when project-specific environmental reviews are conducted, the reviews should
address the potential for impacts to sensitive biological resources and provide
for mitigation as indicated in the DEIR. That is, the General Plan update EIR is
not intended to serve as the baseline conditions in and of itself; rather, it is to
be supplemented with further study and detailed analyses. See also response to
comment A3-7.
B7-15 Thank you for reading and answering my questions. The
attached “Diamond Bar Natural History” project gallery is
one of my on-going tasks. Please notice, pictures of
resident’s input are included, as our Sierra Club helps to
explore and help local wildlife and encourage residents to
follow city wildlife interaction guidelines.
My references follow.
Comment acknowledged. This comment is the closing of the letter and does not
address the adequacy of the Draft EIR; therefore, no further response is
required.
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Chapter 3: Responses to Comments
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Comment ID Comment Response
Thank you.
Diego Tamayo, Diamond Bar student, resident, Youth Field
Intern/Sierra Club
Email: diegonaturalist@gmail.com
References:
Hamilton Biological Report, City of Diamond Bar; Natural
Communities Map 2019
California Vegetation Manual www.veg.cnps.org
L.A. County Oak Woodland Conservation Plan Guide
http://planning.lacounty.gov/assets/upl/project/oakwoodl
ands_conservationmanagement-plan-guide.pdf
B7-16 [Diamond Bar Natural History Project, Diamond Bar-
Pomona Valley Sierra Club Task Force]
Attachment provided in support of comments B7-6 through B7-13, addressed
above.
B7-17 [Biological Resources Report, City of Diamond Bar] Attachment provided in support of comments B7-6 through B7-13, addressed
above.
B7-18 [City of Diamond Bar, Biological Resources Report, Natural
Communities]
Attachment provided in support of comments B7-6 through B7-13, addressed
above.
B8 DIAMOND BAR PRESERVATION ALLIANCE
B8-1 Oct. 31, 2019
To: City of Diamond Bar, Senior Planner Ms. Grace Lee
RE: Comments, General Plan 2040 and DEIR
Dear Ms. Lee,
I am grateful to comment on the City of Diamond Bar,
general plan and DEIR.
This comment is the salutation of the letter and does not address the adequacy
of the Draft EIR; therefore, no further response is required.
B8-2 Here are my main observation and concerns.
Comment acknowledged. The Mitigation Monitoring and Reporting Program for
the General Plan and Draft EIR will include specific instructions for carrying out
the mitigation measures included in the Draft EIR. Mitigation Measure MM-BIO-
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Chapter 3: Responses to Comments
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Comment ID Comment Response
1. A failed mitigation project, Millennium Diamond
Road Partners, has gripped our community with doubt that
the Lead Agency has demonstrated CEQA adherence or
understanding to a due diligent process and best practice.
Today, we see numerous permit violations and apparently
no relief to the failed mitigation at Bonelli Park.
Question: How will the DEIR monitoring and mitigation
plans assure the public of efficiency to avoid such future
failure? The language in the document is not specific. Will
there be a training manual, educating the public how
dependable city procedures are to protect the community
from environmental damage, and loss?
1D states that the City shall implement an Environmental Awareness Program
on its web site intended to increase awareness to developers, residents and city
workers of the sensitive plants, wildlife and associated habitats that occur in the
preserved open space areas. See response to comment B9-7.
B8-3 2. Mitigation options in the DEIR suggest there is a
successful mitigation possible by replacing the removal of
old growth, mature oak trees (which sequester 55
thousand pounds of carbon, per tree each year, with young
oak trees. How is this possible if science teaches oaks must
mature to at least 50 years old to perform carbon capture
of that level. Meaning, it would take fifty years to restore
the lost ecosystem services provided by oaks – and
especially if the oaks were mitigated “off-site” and perhaps
far away. The local community is at a loss of the benefits,
so mitigation can truly not be achieved. What does th e city
say about this realization? (see oak woodland conservation
guide)
Comment acknowledged. As stated on page 3.3-51 of the Draft EIR “While the
City’s tree preservation ordinance and the proposed General Pla n policies
represent an affirmative action, it does not necessarily guarantee that
functioning oak woodlands will be conserved. Therefore, impacts to oak
woodlands and other native woodlands could be significant and unavoidable.”
B8-4 3. Enclosed is a picture of the southern oak riparian
woodland/walnut woodland that was destroyed by scorch
earth grading (December 2017) violating permits and
causing a city issued Cease/Desist. Why does the DEIR
“vegetation community” map depict walnut woodlands
only, in this area? Notice my picture is a strand of riparian
oak woodland which survived rogue bulldozing. Please tell
me, where are the walnut trees. Where are they? Why is
See response to comment B3-9.
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this habitat omitted and misrepresented in the Resource
Conservation figure 5.2?
B8-5 4. The oak woodland preservation language in the
DEIR “sounds” good, but it appears there is little solid
commitment to conservation. City wording feels tentative
and sounds vague. Will the city consider abiding by the
2011 and 2014 Los Angeles County Oak Woodland
Conservation Management Plan Guide? If so, will the city
depend on CalFIRE Urban Forestry leads to guide
preservation of oak woodlands in the city?
http://planning.lacounty.gov/assets/upl/project/oakwoodl
ands_conservation-management-plan-guide.pdf
As stated on page 3.3-53 of the DEIR, “In the event a future project would result
in the loss of an oak woodland, the project shall be subject to the mitigation
requirements set forth in the Los Angeles County Oak Woodland Conservation
Management Plan Guide.” It is important to note the use of the word “shall”
instead of a less assertive command.
B8-6 I was also disappointed the city council chose to affect and
change the general plan and DEIR document, in special
meetings Sept. 25 and Oct. 8th, while at the same time it
was out for Public Review (Sept. 14-Oct.31)
There were approximately 60 language changes processed.
Were the members of the public including stakeholders
notified, other than meeting agendas posted on the
general plan website? Many of us had no idea what was
happening unless we attended the Sept 25 and Oct. 8th
special meetings. How the lack of informing the public
comports with CEQA guidelines?
Comment acknowledged. See response to comment B4-B-40. Revisions to the
draft General Plan policies were provided in the meeting agendas posted to the
General Plan website. The Draft EIR was re-uploaded to the General Plan
website to provide a searchable document in downloadable pieces, but was not
altered during the public review period for the Draft EIR.
B8-7 [Photo]
Millennium Diamond Road project, Diamond Bar, 2017.
Oak woodland riparian, foreground.
Attachment provided in support of comment B8-4, discussed above.
B8-8 In conclusion, the efforts of the Diamond Bar Preservation
Foundation and Alliance aim to protect our community
from suffering devastating environmental damage ever
again. We are also interested in habitat restoration and
promoting native plant landscapes, so to restore the
Comment acknowledged.
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Chapter 3: Responses to Comments
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Comment ID Comment Response
California beauty our neighborhood is famous for and that
we cherish.
I am eager to learn how the city intends to implement
better practices in preserving the natural character of
Diamond Bar.
B8-9 Thank you for review my letter and material and answering
my questions.
Sincerely,
Dr. Chia Teng
President,
Attachments: Hamilton Biological Report & Map, attached
L.A. Oak Woodland Conservation Plan Guide link
http://planning.lacounty.gov/assets/upl/project/oakwoodl
ands_conservation-management-plan-guide.pdf
This comment is the closing of the letter and does not address the adequacy of
the Draft EIR; therefore, no further response is required.
B8-10 [City of Diamond Bar, Biological Resources, Natural
Communities]
Attachments provided in support of comments B8-3 through B8-5, addressed
above.
B8-11 [Biological Resources Report, City of Diamond Bar] Attachments provided in support of comments B8-3 through B8-5, addressed
above.
B9 GARY BUSTEED
B9-1 October 31, 2019
Grace Lee
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765
This comment is the salutation of the letter and does not address the adequacy
of the Draft EIR; therefore, no further response is required.
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Chapter 3: Responses to Comments
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Comment ID Comment Response
Re: Comments on Draft Environmental Impact Report and
Diamond Bar General Plan
Ms. Lee,
B9-2 Thank you very much for the opportunity to provide
comments on Diamond Bar’s Draft Environmental Impact
Report (DEIR) and General Plan (DBGP). The process has
been very open, and I have greatly appreciated the
transparency in which the plan and report development
has been conducted. The General Plan Advisory
Committee provided some reasonable solutions where the
City should focus its development. I appreciate that the
General Plan and EIR have primarily focused on th e
redevelopment of infill or existing commercial areas, rather
than rezoning out existing open spaces for development.
Also you have given some thought and consideration on
how the City of Diamond Bar is part of a larger
environment (Sphere of Influence) that needs to be
thoughtfully considered for wildlife movement and for the
greater ecosystem of the Puente and Chino Hills in general.
The comments I provide below are similar to three of the
priorities identified during the City’s outreach and input in
the GPAC Meetings: Environment, Recreation and Traffic.
Comment acknowledged.
B9-3 Environment
Although I understand that most development will be
targeted in areas of in-fill or reconstruction of existing
commercial areas, we should consider that in areas where
there is potential for sensitive or protected resources, that
we are specific to what would be required to ensure that
the City is in compliance and ensures their protection or
conservation. I am professional environmental specialist,
so these edits are requirements that I am familiar with and
Comment acknowledged.
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are reasonable to implement, and minimize potential for
inadvertent discoveries resulting in schedule delays in
subsequent permitting and mitigation or agency actions
from environmental non-compliance impacts. I would like
to suggest a few minor changes to the language—my
comments are in red and strikeout.
B9-4 RC-P-9 on page 3.3-45
Require, as part of the environmental review process, prior
to approval of discretionary development projects
involving parcels within, adjacent to, or surrounding a
significant biological resource area, a biotic resources
evaluation of the site by a qualified biologist., Focused
plant surveys shall be conducted at the appropriate time of
year, and local reference populations checked to ensure
detectability of the target species. requiring that time-
specific issues such as the seasonal cycle of plants Wildlife
shall also be evaluated by a qualified biologist through
appropriate survey or trapping techniques necessary to
determine presence. and migration of wildlife are
evaluated. Such evaluation shall analyze the existing and
potential natural resources of a given site following at least
one site visit as well as the potential for significant adverse
impacts on biological resources. The report and shall
identify measures to avoid, minimize, or mitigate any
impacts to species that have been observed or have the
potential of being present on the site. that would degrade
its healthy function. In approving any permit based on the
evaluation, the City shall require implementation of
mitigation measures supported by the evaluation, or work
with the applicant to modify the project if mitigation is
determined not to be adequate to reduce the impacts to a
non-significant level.
In the course of providing a project’s environmental review compliant with
CEQA the lead agency (in this case the City) conducts a preliminary review to
determine if the project will have a significant effect on the environment.
Unless it is clear that an EIR is required, the City will prepare an Initial Study to
identify potentially significant effects of the project. If it is determined that
there is no substantial evidence that the project or any of its aspects may cause
a significant effect on the environment a Negative Declaration is prepared to
document this finding. If it is determined that a project may cause a significant
effect on the environment either a Mitigated Negative Declaration (MND) that
provides for the mitigation of potentially significant effects, or, an EIR will be
required. It would be in the case of a MND or an EIR that the applicant would
be required to engage in the types of studies described in the comment.
General Plan Policy RC-P-9, MM-BIO-1A, MM-BIO-1G, and MM-BIO-1J each
speak to the matter of survey timing as written. See response to comment A3-8.
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B9-5 MM-BIO-1A on page 3.3-47
To the extent feasible the preconstruction surveys shall be
completed when species are in bloom, typically between
May and June and reference populations checked. Two
species, the white rabbit-tobacco and San Bernardino
aster, are perennial herbs that grow up to three feet in
height and can be identified by their dried stalks and leaves
following their blooming period.
The suggestion of adding language for checking reference
populations will ensure accuracy of detecting target
sensitive plant species. This requirement is not overly
burdensome, but more of due diligence and ensuring that
the species being surveyed for will even be detectable.
Many sensitive species have identified reference
populations that can be easily checked prior to conducting
any field work—this should save time and effort on
subsequent fieldwork as well.
Comment acknowledged. The proposed language relating to reference site
verification is added to MM-BIO-1A in Chapter 4 of the Final EIR.
B9-6 MM-BIO-1B on page 3.3-47
At a minimum, the plan shall include a description of the
existing conditions of the project and receiver site(s),
transplanting and/or seed collection/off-site seeding or
installation methods, an adaptive two-year monitoring
program, any other necessary monitoring procedures,
plant spacing, and maintenance requirements. In the
event, that the City of DB determines that agreed success
criteria are not met, additional remediation may be
required beyond the two-year maintenance/monitoring
period to ensure mitigation requirements are met. If the
mitigation measure conditions are not met in the
established two-year timeframe, it should be the
Comment acknowledged. The proposed language relating to success criteria and
adaptive management is added to MM-BIO-1B in Chapter 4 of the Final EIR.
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developer’s obligation to meet those mitigation measure
requirements. It has been my experience that there needs
to be assurance that the developer has met obligations. In
the two years of monitoring, there should be adaptive
management of the site to ensure success. This is common
language that many land use agencies have added to their
requirements to put the onus on the developer to ensure
the intent of the mitigation measure is met. My concern
for the City is if it is not clear to the developer on what the
requirements are, the City of Diamond Bar risks being the
responsible party for the additional restoration expense, or
risk the establishment of exotic weed species that could
exacerbate the potential for wildfire.
B9-7 MM-BIO-1D Environmental Awareness Program on page
3.3-48
The City shall implement an Environmental Awareness
Training Program on its web site intended to increase
awareness to developers, residents and city workers of the
sensitive plants, wildlife and associated habitats that occur
in the preserved open space areas. The intention purpose
of the program shall be to inform developers, city workers
and residents. The program shall address safety,
environmental resource sensitivities and impacts
associated with the introduction of invasive plant species
as a result of new development. At a minimum, the
Environmental Awareness Program shall include the
following components:
encourage Provide, on the City website, information about
proactive conservation efforts among for the residents and
city to help conserve the habitats in the preserved open
space. The program shall address impacts associated with
the introduction of invasive plant species as a result of new
Comment acknowledged. “Developers” has been added as being subject to the
Environmental Awareness Program in MM-BIO-1D in Chapter 4 of the Final EIR.
Proposed improvements, such as trails, will be subject to General Plan Goals
and Policies, the mitigation measures set forth in the FEIR and project-specific
CEQA review. It is not reasonable or feasible to compel residents to participate
in a training program as proposed. The first bullet point under Mitigation
Measure 3.3-48 imposes reasonable requirements to increase environmental
awareness.
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development. At a minimum, the Environmental
Awareness Program shall include the following
components:
I appreciate the approach that the City is taking to increase
environmental awareness. My edits were an attempt to
include the developer in this outreach. The Environmental
and Safety Awareness Training should be developed that is
tailored and specific to each project based on resource or
safety concerns. It should be the responsibility of the
contractor or developer to ensure that the workers have
taken the awareness training and provide documentation if
requested by the City of Diamond Bar that the project
proponent understands their role in safety and compliance.
Again, this is a reasonable requirement common on many
construction projects.
B9-8 MM-BIO-1E on page 3.3-49
Preconstruction Surveys for Special-Status Wildlife: Within
one (1) week prior to initiating disturbance activities,
clearance surveys for special-status animal species shall be
performed by a qualified biologist(s) within the boundaries
of the future project disturbances. If any special-status
animals are found on the site, a qualified biologist(s) flag
the area for avoidance and discuss possible seasonal
avoidance measures with the developer. If avoidance is
not feasible, the Project Biologist, with a CDFG Scientific
Collection Permit shall relocate these species to suitable
habitats within surrounding open space areas that would
remain undisturbed, unless the biologist determines that
such relocation cannot reasonably be accomplished at
which point CDFG will be consulted regarding whether
relocation efforts should be terminated. Relocation
methods (e.g., trap and release) and receiver sites shall be
The proposed language is added to MM-BIO-1E in Chapter 4 of the Final EIR.
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verified and approved by the CDFG prior to relocating any
animals.
It is important that as a first option in protection of
resources, avoidance is the preferred option. Therefore,
this measure should include the steps to avoid or minimize
impacts to identified resources. If after all possible
avoidance measures are used, then a qualified biologists
should consider relocation of the resource (ie. plant or
animal). This suggested language is common practice and
is reasonable in consultation with a permitted or approved
biologist.
B9-9 Recreation
As a father of two young girls, recreational opportunities
and parks are very important to my family. I am a member
of the Board for our local AYSO Soccer Region as well as a
coach and referee, so I am familiar with the shortage of
parks for practice and recreation. I also live on the south
side of Diamond Bar, so I also know that the lack of
adequate park facilities on the southern end of town. I was
concerned when I read that the City determined that the
impacts to recreation were Significant and Unavoidable.
You had identified a Core Community Overlay as part of the
DBGP Preferred Alternative. Understanding that the Los
Angeles County Golf Course is not currently a viable
alternative, it was still identified in this EIR as an alternative
option. So, why did the City not consider the golf course in
addressing the significant recreation impacts associated
with the low ratio of 2 acres per 1000 residents? I would
encourage an additional discussion regarding the necessary
acreage needed to mitigate these impacts. As part of the
Core Community Overlay how much of that property could
See response to comment B4-A-6.
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be reserved to meet the requirement of the Quimby Act (5
acres per 1000 residents)?
B9-10 Also, as a question regarding CEQA analysis. It is my
understanding that the Golf Course, in order to be used for
other purposes, would need to be mitigated for that loss
with another comparable location as a golf course. If there
are additional environmental impacts associated with the
Golf Course’s conversion in the Core Community Overlay
option, those impacts would need to be disclosed in this
DEIR. Or alternatively another subsequent EIR would need
to be developed if in the future the Community Overlay
option is viable. Is my assumption correct, that the Golf
Course property is only theoretical and any future
development of that property would be contingent on
another CEQA analysis?
See response to comment B4-A-6.
B9-11 Traffic and other Project Alternatives
As a resident of Diamond Bar, I am well a ware of the issues
around the through traffic on Diamond Bar Blvd, Grand
Ave. and Golden Springs/Colima Road. I understand that
the impacts associated with traffic, although significant for
Level of Service and Vehicle Miles Traveled, would be
difficult to mitigate and therefore are determined to be
unmitigatable. So, I understood that the GPAC elected to
not select, in their recommendations, to continue the
Diamond Bar Blvd and Grand Ave intersection as the
Diamond Bar City Center due to the traffic congestion.
Although I agree with this approach, it does not seem
reasonable that the existing City Center is not analyzed as a
feasible alternative in the EIR. The DEIR only analyzed the
existing City Center as infeasible as the No Project
Alternative under the existing GP. However, I think the
existing City Center warrants an Alternatives Analysis under
the proposed mitigation measures and City land use
See response to comment B4-A-4.
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policies. I suggest that the City analyze this alternative
because the City’s preferred alternative and Alternative 2
are contingent on the Golf Course being developed. These
alternatives, if contingent on the Golf Course, are
incomplete in that the impacts associated with an
alternative county golf course were neither described nor
analyzed in this EIR—and would therefore require a
subsequent EIR analysis. Therefore, it is not clear that
either of these two alternatives are feasible at this time.
B9-12 Again, thank you for your consideration and the
opportunity to provide comments on the DEIR and DBGP. I
look forward to additional correspondence from the City as
the Final EIR becomes available.
Sincerely,
Gary Busteed
20850 Gold Run Drive
Diamond Bar, CA 91765
This comment is the closing of the letter and does not address the adequacy of
the Draft EIR; therefore, no further response is required.
4 Revisions to the Draft EIR
This chapter lists revisions to the Draft EIR by chapter and page, in the same order as the revisions
would appear in the Draft EIR. New text is indicated with an underline and deleted text is indicated
with strikethrough.
Executive Summary
On page ES-4, revise the text as follows.
FOCUS AREAS
Overall, the Proposed Project retains the existing land use framework of the 1995 Gener al Plan,
with some targeted changes. The Proposed Project provides for four focus areas where major land
use changes are planned to take place as part of a strategy to provide walkable mixed -use activity
centers. These focus areas provide opportunities for infill development that can incorporate a range
of housing, employment, and recreational uses to meet the needs of families, young people, senior
citizens, and residents of all incomes.
• The Town Center focus area is proposed along Diamond Bar Boulevard, between SR-60
and Golden Springs Drive, to build on the success of recent commercial redevelopment in
that area.
• The Neighborhood Mixed Use focus area is envisioned as a combination of residential and
ancillary neighborhood -serving retail and service uses to promote revitalization of the
segment of North Diamond Bar Boulevard between the SR -60 interchange and Highland
Valley Road.
• The Transit-Oriented Mixed Use focus area leverages underutilized sites adjacent to the
Metrolink station to provide for higher-density housing, offices, and supporting
commercial uses close to regional transit.
• The Community Core focus area covers the existing Diamond Bar Golf Course, which is
currently operated by Los Angeles County. Should the County choose to discontinue
operation of the golf course or to reduce the size of the golf course, the Community Core
envisioned as a master-planned mixed-use, pedestrian-oriented community and regional
destination.
On page ES-56, revise the text as follows.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-2
3.11 Noise Public Facilities and Recreation
3.11-1 Implementation of the
Proposed Project
would not result in
substantial adverse
physical impacts
associated with the
provision of new or
physically altered
governmental
facilities, need for new
or physically altered
governmental
facilities, the
construction of which
could cause significant
environmental
impacts, in order to
maintain acceptable
service ratios,
response times or
other performance
objectives for fire
protection, police
protection, schools,
parks, or other public
facilities.
None required Less than
significant
N/A
3.11-2 Implementation of the
Proposed Project
would not increase
the use of existing
neighborhood and
regional parks or
other recreational
facilities such that
substantial physical
deterioration of the
facility would occur or
be accelerated.
None required Significant
and
unavoidable
Significant
and
unavoidable
3.11-3 Implementation of the
Proposed Project
would not include
recreational facilities
or require the
construction or
expansion of
recreational facilities
which might have an
adverse physical effect
on the environment.
None required Less than
significant
N/A
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-3
Chapter 3.1: Aesthetics
On page 3.1-11, revise the text as follows.
LU-P-8 Ensure Require that new residential development be compatible with the
prevailing character of the surrounding neighborhood in terms of building scale,
density, massing, and design. Where the General Plan designates higher densities,
provide require adequate transitions to existing development.
On page 3.1-12, revise the text as follows.
LU-P-56 Ensure that development on privately-owned, residentially designated land in
hillside areas is compatible with surrounding natural areas by promoting the
following design principles requiring that development:
a. Minimizes as articulated by the landform grading criteria of the
Hillside Management regulations Ordinance
excavation, grading, and earthwork to retain natural vegetation and
topography;
b. Preserves existing vistas of significant hillside features such as ridgelines,
particularly from public places;
c. Does not create unsafe conditions;
d. Incorporate site and architectural designs that are and is sensitive to natural
contours and land forms and in its site design, including hydrological features;
e. Preserves natural watersheds, including existing vegetation within
undeveloped hillside areas to the maximum extent feasible, including mature
trees and native plant materials;
f. Permits Incorporate fuel modification as part of the Fire
approved fuel modification program;
g. Utilizes planting palettes consisting of drought tolerant, fire resistant, non-
invasive plants that are native to or compatible with those colors similar to
those of native materials in the surrounding area; and
h. Groups plants within swale areas to more closely reflect natural conditions
within landform graded slopes.
On page 3.1-13, revise the text as follows.
RC-P-1 As opportunities arise, Oobtain and designate open space land through acquisition
techniques such as:
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-4
a. Requiring the incorporation of Incorporating open space and recreational
areas into the design of new development projects, preserving and enhancing
as open space significant stands of vegetation, natural landforms, and any areas
of special ecological significance through site design approaches such as
clustering and ecological planning.
b. Allowing clustering or transferring of all or part of the development potential
of a site to a portion of the site to preserve significant environmental resources
such as natural and native habitats (oak woodland, coastal sage scrub, etc.),
natural creeks, artesian springs, vernal pools, seeps, riverines, wetlands,
riparian habitats, wildlife corridors and linkages, and natural geolog ical
features within proposed developments as open space.
c. Allowing for acquisition of open space lands through the entitlement process
and the transfer of densities among land uses of like designation.
d. Collaborating with land trusts and other conservation groups to acquire open
space land through, but not limited to, conservation easements.
On page 3.1-14, revise the text as follows.
RC-P-8 WorkTo the extent feasible, support and cooperate with the efforts of other
jurisdictions and conservation organizations to protect prominent ridges, slopes,
and hilltops in and adjacent to the City and its Sphere of Influence.
Such features include, but are not limited to, areas identified by Los Angeles County
as Significant Ecological Areas; Tonner Canyon; the hills within Tres Hermanos
Ranch; and the hillsides along SR-57, between Diamond Bar and Brea.
On page 3.1-16, revise the text as follows.
RC-P-11 Require that all development, including roads and trails, proposed adjacent to
riparian and other biologically sensitive habitats avoid, to the greatest extent
feasible, significant impacts that would undermine the healthy natural functioning
of those areas. Require that new development proposed in such locations be
designed to:
a. Minimize to the greatest extent possible or eliminate impacts on
environmentally sensitive areas;
b. Protect the visual seclusion of forage areas from road intrusion by providing
vegetative buffering;
c. Protectvide wildlife movement linkages to water, food, shelter, and nesting
sites;
d. Allow wildlife and migration access by use of tunnels or other practical means;
e. Provide vegetation that can be used by wildlife for cover along roadsides;
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-5
f. Avoid intrusion of night lighting into identified areas through properly
designed lighting systems;
g. Avoid impacts to wetlands, natural springs and seeps and maintain access for
wildlife or when natural water areas are removed or blocked provide a locally
suitable and equal replacement; and
h. To the greatest extent possible, prevent street water runoff from flowin g into
waterways
Chapter 3.2: Air Quality
On page 3.2-34, revise the text as follows.
LU-P-17 Promote Require that site designs that create active street frontages and introduce
pedestrian-scaled street networks and street designs.
LU-P-34 Ensure Require that development incorporates evaluates and mitigates to extent
practical noise and air quality issues related to the proximity of th e SR-60 and
Metrolink.
LU-P-49 Promote Require convenient, attractive, and safe pedestrian, bicycle, and transit
connections both within the Community Core area and between the Community
Core and surrounding neighborhoods and other destinations within Diam ond
Bar.
On page 3.2-34, revise the text as follows.
CR-P-6 Require that all new development study the impact of vehicle miles traveled (VMT)
and Continue to implement congestion mitigation measures to ensure that new
projects do not significantly increase local City congestion based on defined level
of service (LOS) standards.
CR-P-32 Provide Promote pedestrian and bicycle connectivity in existing residential
neighborhoods, utility easements, and/or flood control channels, including
connections through cul -de-sacs to other streets or community facilities where
feasible.
CR-P-55 Consider the establishment of Incorporate common bicycle parking requirements
for appropriate uses including multi-family residential and office in the
Municipal Code.
On page 3.2-35, revise the text as follows.
RC-P-10 Require, to the greatest extent feasible, new development to preserve mature native
trees including oak and walnut, and trees of significant cultural or historical value
such as sycamore and arroyo willow, etc., as set forth under the Diamond Bar Tree
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-6
Preservation and Protection Ordinance. Review the ordinance periodically and
update it as necessary to reflect current best practices.
RC-P-19 Require new development to reduce the waste of potable water through the use o f
drought-tolerant plants, efficient landscape design and application, and reclaimed
water systems.
RC-P-20 Require the implementation of the latest water conservation technologies into new
developments.
RC-P-21 Require builders to provide information to prospective buyers or tenants within
the City of Diamond Bar regarding drought -tolerant planting concepts.
RC-P-22 Require the use of mulch in landscape areas to improve the water holding capacity
of the soil by reducing evaporation and soil compaction in accordance with the
-Efficient Landscape
Ordinance.
On page 3.2-35, revise the text as follows.
RC-P-33 29. Ensure that project applicants Cconsult with SCAQMD when siting new facilities
with dust, odors, or Toxic Air Contaminant (TAC) emissions to avoid siting those
facilities near sensitive receptors and avoid siting sensitive receptors near sources
of air pollution. Require proposed land uses that produce TACs to incorporate
setbacks and design features that reduce TACs at the source to minimize potential
impacts from TACs. For new or modified land uses that have the potential to emit
dust, odors, or TACs that would impact sensitive receptors require the business
owners to notify the SCAQMD, and residents and businesses adjacent to the
proposed use prior to business license or building permit issuance. (New from
SCAQMD Guidance)
Examples of facilities that may emit TACs as identified by the SCAQMD include dry
cleaners, gas stations, auto body shops, furniture repair shops, warehouses, printing
shops, landfills, recycling and transfer stations, and freeways and roadways. Refer to
SCAQMD guidance for the most current list of facilities that may emit TACs.
RC-P-304 For new or modified land uses that have the potential to emit dust, odors, or TACs
that would impact sensitive receptors, require the business owners to obtain all
necessary notify the SCAQMD clearances or permits, and residents and businesses
adjacent to the proposed use prior to business license or building permit issuance.
Sensitive receptors include residences, schools, childcare centers, playgrounds, parks
and other recreational facilities, nursing homes, hospitals, and other medical care
facilities.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-7
On page 3.2-26, revise the text as follows.
CHS-P-5 As opportunities and resource become available, Iimplement street design features
that facilitate walking and biking in both new and established areas. Require a
minimum standard of these features for all new developments where appropriate
and feasible.
CHS-P-14 Encourage the development of Develop and incorporate such as
the clusters of commercial uses that draw residents from the entire community
into the Neighborhood Mixed Use, the Transit -Oriented Mixed Use, and the Town
Center focus areas.
CHS-P-15 Establish opportunities for Encourage the establishment of gathering areas in new
neighborhoods.
CHS-P-33 Plan Encourage land uses to reduce vehicle miles traveled (VMT), prioritizing infill
development and incorporating vertical and horizontal mixed -use development,
public transit, and active transportation facilities where appropriate, recognizing
that the transportation sector is the largest source of GHG emissions in Diamond
Bar and in California more broadly.
CHS-P-38 Accelerate Consider the adoption of rooftop and parking lot solar power and/or
other alternative energy usage on developed sites in Diamond Bar through ac tions
such as:
a. Establishing incremental growth goals for solar power/alternative energy
systems in Diamond Bar;
b. Developing guidelines, recommendations, and examples for cost -effective
solar and/or other alternative energy-based installation; and
c. Installing solar/alternative energy technology on available existing City
facilities spaces.
On page 3.2-37, revise the text as follows.
CHS-P-57 Encourage water conservation, drought-tolerant landscaping and the use of
greywater and reclaimed and recycled water, where appropriate, with a view to
reducing water use.
On page 3.2-41, revise the text as follows.
MM-AQ-1 Construction Features. Future development projects implemented under the
General Plan will be required to demonstrate consistency with SCAQMD
construction emission thresholds. Where emissions from individual projects
exceed SCAQMD thresholds, the following measures shall be incorporated as
necessary to minimize impacts. These measures do not exclude the use of other,
equally effective mitigation measures.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-8
▪ Require all off-road diesel equipment greater than 50 horsepower (hp)
used for this Project to meet current USEPA standards, which are
currently Tier 4 final off -road emission standards or equivalent. Such
equipment shall be outfitted with Best Availabl e Control Technology
(BACT) devices including a California Air Resources Board certified Level
3 Diesel Particulate Filter (DPF) or equivalent. This DPF will reduce diesel
particulate matter and NOX emissions during construction activities.
▪ Require a minimum of 50 percent of construction debris be diverted for
recycling.
▪ Require building materials to contain a minimum 10 percent recycled
content.
▪ Require materials such as paints, primers, sealants, coatings, and glues to
have a low volatile organic compound concentration compared to
conventional products. If low VOC materials are not available,
architectural coating phasing should be extended sufficiently to reduce the
daily emissions of VOCs.
Chapter 3.3: Biological Resources
On page 3.3-6, revise the text as follows.
Native Grasslands
Native grasslands are a sensitive natural community with the potential to occur in the Planning
Area. In addition, native grassland species may occur in areas of shrublands, scrub, and oak
woodland. Areas of p erennial grassland, distinguished by possessing non -trace cover of native
grasses, are identified as Sensitive by CDFW. The Nassella spp. Melica spp. Herbaceous alliance
is characterized by having at least two to five percent cover of native needlegrass (Nassella spp.) or
other native grasses. The Bromus carinatus Elymus glaucus herbaceous alliance has California
brome (Bromus carinatus) characteristically present, with native plants providing more than 10
percent relative cover. Vernal pools and seasonal ponds could occur in grasslands within the
Planning Area, and/or along dirt roads that pass through other natural communities within the
Planning Area.
On page 3.3-10, revise Figure 3.3-1 as follows.
On page 3.3-11, revise Figure 3.3-2 as follows.
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LOS ANGELES
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Oak Woodland
Walnut Woodland
Sycamore Alluvial Woodland
Non-Native Woodland
Non-Native Grassland
Non-Native Riparian
Southern Willow Scrub
Venturan Coastal Sage Scrub
Disturbed Venturan Coastal Sage Scrub
Disturbed
Diamond Bar Golf Course
Developed
City of Diamond Bar
Sphere of Influence
0 0.75 1.50.375
MILES
Source: City of Diamond Bar 2019;
ESA PCR, 2016; Dyett & Bhatia, 2019 RiversideMetrolinkLineFigure 3.3-1: Natural Communities
Due to the scale of the mapping effort the refinement of the
delineation of coast live oak woodland and walnut woodland was
based on the slope face compass direction (nor th and east facing
for coast live oak woodland and south and west facing for walnut
woodland) and is subject to site-specific studies for individual
projects.
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0 0.5 10.25
MILES
Blueline Streams
Potentially Jurisdictional Drainages
City of Diamond Bar
Sphere of Influence
County Boundary
Figure 3.3-2: Major Waterways and
Tributaries
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-11
On page 3.3-12, revise the text as follows.
United States Fish and Wildlife Service (USFWS) designated critical habitat for listed plant o r
wildlife species does not occur within the Planning Area. The nearest critical habitat for the Coastal
California gnatcatcher is located within the southwest corner of the SOI and extends through the
Puente-Chino Hills Wildlife Corridor in the City of Pu ente Hills located to the southwest of the
SOI . Additional critical habitat for the Coastal California gnatcatcher is located within the City of
Walnut and within Chino Hills State Park but is not adjacent to the Planning Area boundaries.
On page 3.3-34, revise the text as follows.
As a point of clarification and in accordance with revised interpretive guidelines provided in the
3345 on December 22, 2017, the
killing, or attempting to do the same applies only to direct and affirmative purposeful actions that
reduce migratory birds, their eggs, or their nests, by killing or capturing, to human control.
On page 3.3-37, revise the text as follows.
California Department of Fish and Wildlife
The California Department of Fish and Wildlife (CDFW) provides guidance on appropriate
methods within Addressing Sensitive Natural Communities in Environmental Review. The
• Identify all Natural Communities within the project footprint using the best means
possible, for example, keying them out in the Manual of California, Second Edition (Sawyer
et al. 2009) or in classification or mapping reports from the region, available on
• Refer to the current standard list of Natural Communities to determine if any of these types
are ranked Sensitive (S1 -S3 rank); if so, see CEQA Guidelines checklist at IVb.
• Other considerations when assessing potential impacts to Sensitive Natural Communities
from a project include:
1. Compliance with state and federal wetland and riparian policies and codes, as certain
Natural Communities are restrict ed to wetlands or riparian settings.
2. Compliance with the Native Plant Protection Act and the state and federal Endangered
Species Acts, as some Natural Communities either support rare species or are defined
by the dominance or presence of such species.
3. Compliance with CEQA Guidelines Section 15065(a), which mandates completion of
an EIR if a project would threaten to eliminate a plant community.
4. Compliance with local regional plans, regulations, or ordinances that call for
consideration of impacts to Natural Communities.
5.
rare or unique to the region under CEQA Guidelines Section 15125(c).
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-12
• If a Natural Community in the project area has not previously been described, it may be a
rare type. In this case, please contact VegCAMP about documenting the Natural
Community.
• If there are Sensitive Natural Communities on your project site and you need guidance,
contact the appropriate regional staff person through the local CDFW Region al Office to
discuss potential project impacts; these staff have local knowledge and context.
•
Status Native Plant Populations and Natural Communities provides information on
reporting.
On page 3.3-35, revise the text as follows.
RC-G-6. Promote the use of native and drought -tolerant vegetation in landscaping where
practical. Utilize native and drought-tolerant vegetation in landscaping, site
stabilization and restoration where practical to prevent the spread of invasive plant
species into natural open spaces.
RC-P-9. Require, as part of the environmental review process prior to approval of
discretionary development projects involving parcels within, adjacent to, or
surrounding a significant biological resource area, a biotic resources evaluation of
the site by a qualified biologist ,. Focused plant surveys shall be conducted at the
appropriate time of year, and local reference populations checked to ensure
detectability of th e target species. Wildlife shall also be evaluated by a qualified
biologist through appropriate survey or trapping techniques necessary to
determine presence. requiring that time-specific issues such as the seasonal cycle
of plants and migration of wildlif e are evaluated. Such evaluation shall analyze the
existing and potential natural resources of a given site following at least one site
visit as well as the potential for significant adverse impacts on biological resources ,
and. The report shall identify measures to avoid, minimize, or mitigate any impacts
to species that have been observed or have the potential of being present on the
site. that would degrade its healthy function. In approving any permit based on the
evaluation, the City shall require impl ementation of mitigation measures
supported by the evaluation, or work with the applicant to modify the project if
mitigation is determined not to be adequate to reduce the impacts to a non -
significant level.
On page 3.3-46, revise the text as follows.
RC-P-10 Require, to the greatest extent feasible, new development to preserve mature native
trees including oak and walnut, and trees of significant cultural or historical value
such as sycamore and arroyo willow, etc., as set forth under the Diamond Bar Tree
Preservation and Protection Ordinance. Review the ordinance periodically and
update it as necessary to reflect current best practices.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-13
RC-P-11 Require that all development, including roads and trails, proposed adjacent to
riparian and other biologically sensitive habitats avoid, to the greatest extent
feasible, significant impacts that would undermine the healthy natural functioning
of those areas. Require that new development proposed in such locations be
designed to:
a. Minimize to the greatest extent poss ible or eliminate impacts on
environmentally sensitive areas;
b. Protect the visual seclusion of forage areas from road intrusion by providing
vegetative buffering;
c. Protectvide wildlife movement linkages to water, food, shelter, and nesting
sites;
d. Allow wildlife and migration access by use of tunnels or other practical means;
e. Provide vegetation that can be used by wildlife for cover along roadsides;
f. Avoid intrusion of night lighting into identified areas through properly
designed lighting systems;
g. Avoid impacts to wetlands, natural springs and seeps and maintain access for
wildlife or when natural water areas are removed or blocked provide a locally
suitable and equal replacement; and
h. To the greatest extent possible, prevent street water runoff from flowi ng into
waterways
RC-P-14 Partner Support and cooperate with the efforts of local school districts,
environmental groups and volunteers to offer environmental education programs.
On pages 3.3 -47 through 3.3-49 , revise the text as follows.
Mitigation Measures
The Proposed Project could result in potentially significant impacts on special-status plant and
wildlife species during both construction and use of specific projects, including plant and animal
species included in Tables 3.3-3 and 3.3 -4, as well as nesting birds protected under the MTBA and
CDFG Code (3503). However, implementation of project-specific Mitigation Measures MM BIO-
1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I and 1k will minimize impacts so as to be less than significant.
Mitigation Measures MM BIO-1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, and 1K apply to future
development under the Proposed Project in the following areas where special -status species have
been identified: Planning Area 1 (Tres Hermanos Ranch), Planning Area 2, Planning Area 4 (under
the South Pointe West Specific Plan), and the Golf Course. It should be noted that assessing
potential impacts to which one or more of the MM -BIO-1 may apply, both direct (on-site) and
indirect (off -site) should be considered.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-14
MM-BIO-1A Preconstruction Surveys for Special-Status Plants: To mitigate impacts on special
status plant species, the applicant shall implement the following measures:
• Prior to initiating disturbance activities, clearance surveys for special -status
plant species shall be p erformed by a qualified biologist(s) within the
boundaries of the future project disturbances. If any special-status plants are
found on the Planning Area, a qualified biologist(s) with a CDFG Scientific
Collection Permit shall prepare a plan to relocate these species to suitable
habitats within surrounding public open space areas that would remain
undisturbed. For those species that cannot be physically transplanted, the
biologist(s) shall collect seeds from the plants.1
• To the extent feasible the preconstruction surveys shall be completed when
species are in bloom, typically between May and June and reference
populations checked . Two species, the white rabbit -tobacco and San
Bernardino aster, are perennial herbs that grow up to three feet in height and
can be identified by their dried stalks and leaves following their blooming
period.
MM-BIO-1B Special-Status Plant Planting Plan: Prior to any ground disturbance for projects
that have the potential to cause direct or indirect impacts on special -status plants,
the project applicants shall prepare a Special Status Plant Planting Plan for the
species to be transplanted. At a minimum, the plan shall include a description of
the existing conditions of the project and receiver site(s), transplanting and/or seed
collection/off-site seeding or installation methods, an adaptive two-year
monitoring program, any other necessary monitoring procedures, plant spacing,
and maintenance requirements. In the event that the City of Diamond Bar
determines that agreed success criteria are not met, additional remediation may be
required beyond the two-year maintenance/monitoring period to ensure
mitigation requirements are met. The City shall also require proof that the plan
preparer consulted with US Fish and Wildlife Service and California Department
of Fish and Wildlife personnel or appropriate herbarium botanists in order to
maximize transplanting success.2
MM-BIO-1C Listed Endangered and Threatened Plants: In addition to MM BIO-1A and -1B,
the City shall require the project applicant to provide proof of the US Fish and
Wildlife Service and California Department of Fish and Wildlife permitting the
take of listed endangered and threatened plants. The FESA does not address listed
plants on private property. However, if a federal action is required for a project
(funding, Clean Water Act compliance, etc.), a permit from the USFWS and
CDFW to take a listed species is required.
1 Lilies generally can be transplanted in bulb-form.
2 Such as CDFW in Ontario, the Rancho Santa Ana Botanical Gardens in Claremont, UC Riverside, or Cal Poly Pomona.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-15
MM-BIO-1D Environmental Awareness Program: In order to reduce indirect impacts on
special-status plants, sensitive natural communities, preserved open space and
wildlife corridors, the City shall implement the following measures:
• The City shall implement an Environmental Awareness Program on its web
site intended to increase awareness to developers, residents and city workers
of the sensitive plants, wildlife and associated habitats that occur in the
preserved open sp ace areas. The intention of the program shall be to inform
developers, city workers, and residents and encourage active conservation
efforts among the residents and city to help conserve the habitats in the
preserved open space. The program shall address impacts associated with the
introduction of invasive plant species as a result of new development . At a
minimum, the Environmental Awareness Program shall include the foll owing
components:
o Informational kiosks shall be added or modified at entrance points to
hiking and equestrian trails to inform city workers, residents and trail
users on the sensitive flora and fauna that rely on the habitats found within
the preserved op en space. The intent of these kiosks is to bring awareness
to the sensitive plants, wildlife and associated habitats which occur in the
area.
o For informational purposes, tThe City shall provide future project
applicants a brochure which includes a list of sensitive plant and tree
species to avoid impacting as well as suggested plant palettes to be used in
residential landscaping near natural areas to prevent the introduction of
invasive plant species to the surrounding natural communities.
MM-BIO-1E Preconstruction Surveys for Special -Status Wildlife: Within one (1) week prior to
initiating disturbance activities, clearance surveys for special -status animal species
shall be performed by a qualified biologist (s) within the boundaries of the future
project disturbances. If any special -status animals are found on the site, a qualified
biologist(s) flag the area for avoidance and discuss possible seasonal avoidance
measures with the developer. If avoidance is not feasible, the Project Biologist, with
a CDFG Scientific Collection Permit shall relocate these species to suitable habitats
within surrounding open space areas that would remain undisturbed, unless the
biologist determines that such relocation cannot reasonably be accomplished at
which point CDFG will be consulted regarding whether relocation efforts should
be terminated. Relocation methods (e.g., trap and release) and receiver sites shall
be verified and approved by the CDFG prior to relocating any animals.
On page 3.3-50, revise the text as follows.
MM-BIO-1H Protection of Eagle Nests: No development or project activities shall be permitted
within one-half mile of a historically active or determined active golden eagle nest
unless the planned activities are sited in such a way that the activity has mi nimal
potential to cause abandonment of the nesting site, as determined by a qualified
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-16
biologist.3 In addition, the eagle nest (if active) shall be monitored by a biologist
who is highly familiar with the signs of eagle distress during the project
development activities. The monitoring shall continue until the monitoring
biologist is confident the nest will not be disturbed. The monitoring biologist shall
have the authority to stop project activities as needed.
On page 3.5-52, revise the text as follows.
Therefore, impacts to oak woodlands and other native woodlands could be significant and
unavoidable without mitigation.
On page 3.3-58, revise the text as follows.
LU-P-56 Ensure that development on privately-owned, residentially designated land in
hillside areas is compatible with surrounding natural areas by promoting the
following design principles requiring that development:
a. Minimizes as articulated by the landform grading criteria of the
Hillside Management regulations Ordinance
excavation, grading, and earthwork to retain natural vegetation and
topography;
b. Preserves existing vistas of significant hillside features such as ridgelines,
particularly from public places;
c. Does not create unsafe conditions;
d. Incorporate site and architectural designs that are and is sensitive to natural
contours and land forms and in its site design, including hydrological features;
e. Preserves natural watersheds, including existing vegetation within
undeveloped hillside areas to the maximum extent feasible, in cluding mature
trees and native plant materials;
f. Permits Incorporate fuel modification as part of the Fire
approved fuel modification program;
g. Utilizes planting palettes consisting of drought tolerant, fire resistant, non-
invasive plants that are native to or compatible with those colors similar to
those of native materials in the surrounding area; and
h. Groups plants within swale areas to more closely reflect natural conditions
within landform graded slopes.
3 Generally, information regarding the location of r aptorial bird nests is kept highly confidential. As such it is
recommended that representatives of CDFW, USFWS and/or the Chino Hills State Park be notified of any proposed
projects in the SOI or Tres Hermanos portions of the Planning Area. In consultati on with agency representatives, it
can be determined if the project is within one -half mile of the eagle nest without the location being specifically
identified.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-17
RC-P-25. Control and improve the quality of stormwater entering local water bodies by
requiring new development to incorporate best management practices (BMPs),
and Low Impact Development (LID) strategies that support on -site retention,
detention, and/or treatment of stormwater through means such as infiltration,
evapotranspiration, biofiltration, and rainfall harvest and use.
RC-P-26. Require the implementation of a stormwater pollution prevention plan (SWPPP),
and inspection by a Construction General Permit Qualified SWPPP Practit ioner
(QSP), during construction and post construction to limit land disturbance
activities such as clearing and grading and cut -and-fill; avoid steep slopes, unstable
areas, and erosive soils; and minimize disturbance of natural vegetation and other
physical or biological features important to preventing erosion or sedimentation.
On page 3.3-59 , insert Figure 3.3-5 as follows.
!(T
Walnut
Pomona
Industry
LOS ANGELES
COUNTY
ORANGE COUNTY
SAN BERNARDINO
COUNTY
Metrolink
Station
}}}60
}}}57
}}}60
}}}57
Choke Points
Natural Communities
Developed
City of Diamond Bar
Sphere of Influence
0 0.75 1.50.375
MILES
Source: City of Diamond Bar 2019;
ESA PCR, 2016; Dyett & Bhatia, 2019 RiversideMetrolinkLineFigure 3.3-5 Movement Choke Points
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-19
On page 3.3-64, revise the text as follows.
RC-P-4 Maintain an inventory of open lands whichthat were set aside for open space uses
as part of previous developments approvedals through the County prior to City
incorporation, and require verification as to the existence of any potential open
space restrictions previously approved on a subject property prior to
acceptingapproving development proposals.
RC-P-8 WorkTo the extent feasible, support and cooperate with the efforts of other
jurisdictions and conservation organizations to protect prominent ridges, slopes,
and hilltops in and adjacent to the City and its Sphere of Influence.
Such features include, but are not limited to, areas identified by Los Angeles County
as Significant Ecological Areas; Tonner Canyon; the hills within Tres Hermanos
Ranch; and the hillsides along SR-57, between Diamond Bar and Brea.
Chapter 3.4: Cultural, Historic, and Tribal Cultural
Resources
On page 3.4-20, revise the text as follows.
LU-P-8 EnsureRequire that new residential development be compatible with the prevailing
character of the surrounding neighborhood in terms of building scale, density,
massing, and design. Where the General Plan designates higher densities,
providerequire adequate transitions to existing development.
LU-P-12 Require Ensure that commercial uses and shopping centers are designed in a
manner compatible with adjacent residential areas in terms of traffic and noise
impacts, building scale, and appropriate transitions and buffers.
LU-P-18 Require dDevelopment toshould be sensitive to the building form, density,
massing, and scale of surrounding residential neighborhoods.
Chapter 3.5: Energy, Climate Change, and Greenhouse
Gases
On page 3.5-36, revise the text as follows.
LU-P-17 PromoteRequire that site designs that create active street frontages and introduce
pedestrian-scaled street networks and street designs.
LU-P-49 PromoteRequire convenient, attractive, and safe pedestrian, bicycle, and transit
connections both within the C ommunity Core area and between the Community
Core and surrounding neighborhoods and other destinations within Diamond
Bar.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-20
CR-P-6 Require that all new development study the impact of vehicle miles traveled (VMT)
and Continue to implement congestion mitigation measures to ensure that new
projects do not significantly increase local City congestion based on defined level
of service (LOS) standards.
CR-P-32 Provide Promote pedestrian and bicycle connectivity in existing residential
neighborhoods, utility easements, and/or flood control channels, including
connections through cul -de-sacs to other streets or community facilities where
feasible.
CR-P-55 Consider the establishment of Incorporate common bicycle parking requirements
for appropriate uses including multi-family residential and office in the
Municipal Code.
RC-P-10 Require, to the greatest extent feasible, new development to preserve mature native
trees including oak and walnut, and trees of significant cultural or historica l value
such as sycamore and arroyo willow, etc., as set forth under the Diamond Bar Tree
Preservation and Protection Ordinance. Review the ordinance periodically and
update it as necessary to reflect current best practices.
RC-P-198 RequireEnsure new development to reduce the waste of potable water through the
use of drought -tolerant plants, efficient landscape design and application, and
reclaimed water systems where available.
RC-P-20 19 RequireEncourage the implementation of the latest water conservation
technologies into new developments.
RC-P-21 20 RequireEnsure buildersdevelopers to provide information to prospective buyers or
tenants within the City of Diamond Bar regarding drought -tolerant planting
concepts.
RC-P-22 Require the use of mulch i n landscape areas to improve the water holding capacity
of the soil by reducing evaporation and soil compaction in accordance with the
-Efficient Landscape
Ordinance.
On page 3.5-37, revise the text as follows.
CHS-P-5 As opportunities and resource become available, Iimplement street design features
that facilitate walking and biking in both new and established areas. Require a
minimum standard of these features for all new developments where appropriate
and feasible.
CHS-P-14 Encourage the development of Develop and incorporate such as
the clusters of commercial uses that draw residents from the entire community
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-21
into the Neighborhood Mixed Use, the Transit -Oriented Mixed Use, and the Town
Center focus areas.
CHS-P-15 Establish opportunities for Encourage the esta blishment of gathering areas in new
neighborhoods.
CHS-P-33 Plan Encourage land uses to reduce vehicle miles traveled (VMT), prioritizing infill
development and incorporating vertical and horizontal mixed -use development,
public transit, and active transportation facilities where appropriate, recognizing
that the transportation sector is the largest source of GHG emissions in Diamond
Bar and in California more broadly.
CHS-P-35 Use the City's CAP as the platform when considering for outlining and
implementing measures to improve energy conservation and increase renewable
energy use in existing and new development.
CHS-P-38 Accelerate Consider the adoption of rooftop and parking lot solar power and/or
other alternative energy usage on developed sites in Diamond Bar through actions
such as:
a. Establishing incremental growth goals for solar power/alternative energy
systems in Diamond Bar;
b. Developing guidelines, recommendations, and examples for cost -effective
solar and/or other alternative energy-based installation; and
c. Installing solar/alternative energy technology on available existing City
facilities spaces.
CHS-P-523 Support and cooperate with County and State regulatory agency efforts to Rrequire
commercial and industrial generators to develop and implement a source
reduction and recycling plan tailored to their individual waste streams.
CHS-P-535 Encourage the protection Protect and enhancement of areas identified as healthy
functioning ecosystems that provide the ecological, cultural, public health and
safety, and economic value of ecosystem services, or benefits.
On page 3.5-49, revise the text as follows.
CR-P-1 When redesigning streets, plan for the needs of different modes by incorporating
considering elements such as shade for pedestrians, safe pedestri an-friendly
crossings/intersections, lighting at the pedestrian scale, bike lanes, signage visible
to relevant modes, transit amenities, etc.
CR-P-2 Require that Promote new street designs and efforts to retrofit existing streets in
residential neighborhoods minimize traffic volumes and/or speed as appropriate
without compromising connectivity for emergency vehicles, bicycles, pedestrians,
and users of mobility devices.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-22
CR-P-6 Require that all new development study the impact of vehicle miles traveled (VMT)
and Continue to implement congestion mitigation measures to ensure that new
projects do not significantly increase local City congestion based on defined level
of service (LOS) standards.
CR-P-24 As opportunities arise, cCoordinate with loca l, regional, and State agencies to
encourage and support programs that reduce vehicle miles traveled, such as
preferential carpool and car share parking, parking pricing, on -site childcare,
flexible work schedules, subsidized transit passes, and ridesharin g.
CR-P-32 Provide Promote pedestrian and bicycle connectivity in existing residential
neighborhoods, utility easements, and/or flood control channels, including
connections through cul -de-sacs to other streets or community facilities where
feasible.
CR-P-53 UpdateConsider updating parking standards in the Municipal Development Code
parking demand and taking into consideration demographics and access to
alternative modes of transportation.
CR-P-54 Consider incorporatingIncorporate criteria in the MunicipalDevelopment Code to
allow reductions in parking requirements in exchange for VMT reduction
measures.
CR-P-55 Consider the establishment of Incorporate common bicycle parking requirements
for appropriate uses including multi-family residential and office in the
Municipal Code.
CR-P-57 Consider incentives to encourage carpooling, such as Incentivize the provision of
preferential parking for high-occupancy vehicles to encourage carpooling.
CR-P-59 As opportunities arise, Wwork with Caltrans to evaluate existing Caltrans -
operated park-n-ride facilities within the City and expand the facilities where
necessary.
On page 3.5-51, revise the text as follows.
CHS-P-5 As opportunities and resource become available, Iimplement street design features
that facilitate walking and biking in both new and established areas. Require a
minimum standard of these features for all new developments where appropriate
and feasible.
CHS-P-14 Encourage the development of Develop and incorporate such as
the clusters of commercial uses that draw residents from the entire community
into the Neighborhood Mixed Use, the Transit -Oriented Mixed Use, and the Town
Center focus areas.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-23
CHS-P-15 Establish opportunities for Encourage the establishment of gathering areas in new
neighborhoods.
CHS-P-33 Plan Encourage land uses to reduce vehicle miles traveled (VMT), prioritizing infill
development and incorporating vertical and horizontal mixed -use development,
public transit, and active transportation facilities where appropriate, recognizing
that the transportation sector is the largest source of GHG emissions in Diamond
Bar and in California more broadly.
CHS-P-35 Use the City's CAP as the platform when considering for outlining and
implementing measures to improve energy conservation and increase renewable
energy use in existing and new development.
CHS-P-38 Accelerate Consider the adoption of rooftop and parking lot solar power and/or
other alternative energy usage on developed sites in Diamond Bar through actions
such as:
a. Establishing incremental growth goals for solar power/alternative energy
systems in Diamond Bar;
b. Developing guidelines, recommendations, and examples for cost -effective
solar and/or other alternative energy-based installation; and
c. Installing solar/alternative energy technology on available existing City
facilities spaces.
Chapter 3.6: Geology, Soils, and Seismicity
On page 3.6-27, revise the text as follows.
LU-P-56 Ensure that development on privately-owned, residentially designated land in
hillside areas is compatible with surrounding natural areas by promoting the
following design principles requiring that development:
a. Minimizes as articulated by the landform grading criteria of the
Hillside Management regulations Ordinance
excavation, grading, and earthwork to retain natural vegetation and
topography;
b. Preserves existing vistas of significant hillside features such as ridgelines,
particularly from public places;
c. Does not create unsafe conditions;
d. Incorporate site and architectural designs that are and is sensitive to natural
contours and land forms and in its site design, including hydrological features;
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-24
e. Preserves natural watersheds, including existing vegetation within
undeveloped hillside areas to the maximum extent feasible, including mature
trees and native plant materials;
f. Permits Incorporate fuel modification as part of the Fire
approved fuel modification program;
g. Utilizes planting palettes consisting of drought tolerant, fire resistant, non-
invasive plants that are native to or compatible with those colors similar to
those of native materials in the surrounding area; and
h. Groups plants within swale areas to more closely reflect natural conditions
within landform graded slopes.
On page 3.6-28, revise the text as follows.
PS-P-1 Require new emergency facilities subject to City land use regulations and
permitting requirements, including, but not limited to, fire stations, paramedic
services, police stations, hospitals, ambulance services, and emergency operations
centers be designed to withstand and remain in operation following the maximum
credible earthquake event.
PS-P-4 Carry out a review of City-owned critical facilities that may be vulnerable to major
earthquakes and landslides and develop programs to upgrade them.
PS-P-6 Prevent and control soil erosion and corresponding landslide risks on public
property and in conjunction with new private development through hillside
protection and management.
On page 3.6-29, revise the text as follows.
RC-P-26 Require the implementation of a stormwater pollution prevention plan (SWPPP),
and inspection by a Construction General Permit Qualified SWPPP Practitioner
(QSP), during construction and post construction to li mit land disturbance
activities such as clearing and grading and cut -and-fill; avoid steep slopes, unstable
areas, and erosive soils; and minimize disturbance of natural vegetation and other
physical or biological features important to preventing erosion or sedimentation.
On page 3.6-32, revise the text as follows.
As new development occurs, the LACSD requires the new developments to annex into its service
area for operation, maintenance, and treatment services. The LACSD are empowered by the
California Health and Safety Code to charge a fee for the privilege of connecting (directly or
indirectly) to the Districts' Sewerage System for increasing the strength or quantity of wastewater
discharged from connected facilities. This connection fee is a capital facilities fee that is imposed in
an amount sufficient to construct an incremental expansion of the Sewerage System to
accommodate the proposed project. Payment of a connection fee will be required before any
development projects are permitted to discharge to the Districts' Sewerage System.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-25
On page 3.6-33, revise the text as follows.
PF -P-310 Require, when appropriate, the construction of water, sewer, drainage, and other
necessary public facilities, and encourage storm water capture prior to or
concurrent with new development.
PF -P-312 Require, when appropriate, project sponsors to provide all necessary infrastructure
improvements, including the pro rata share of system-wide improvements.
PF -P-323 Maintain a development fee structure that ensures, when appropriate, that costs
for new capital facilities and expansion of existing facilities necessitated by the
approval of new development or intensification of existing development are
funded by the proponents or beneficiaries of projects, in proportion to the deman d
created by the development.
PF -P-387 As opportunities arise, Wwork with the Los Angeles County Public Works
Department (LACPWD) and Los Angeles County Sanitation District (LACSD) to
ensure that wastewater treatment conveyance systems and treatment facili ty
capacity is available to serve planned development within Diamond Bar.
Chapter 3.7: Hazards, Hazardous Materials, and Wildfire
On page 3.7-33, revise the text as follows.
PS-P-38 Maintain, review, and update Diamond Bar's Local Hazard Mitigation Plan as
needed to take every five years, taking into account new hazard conditions in the
Planning Area and new emergency management techniques.
On page 3.7-34, revise the text as follows.
CR-P-62 Revise the designation of truck routes to minimize truck traffic through or near
residential areas. Maintain truck routes with signage between industrial areas and
freeway interchanges to discourage truck travel through residential
neighborhoods, and provide truck route information to truck routing software
providers.
On page 3.7-37, revise the text as follows.
PS-P-26 Prohibit ) the development of
projects that would reasonably be anticipated to emit hazardous air emissions or
handle extremely hazardous substances within a quarter-mile of a school.
On page 3.7-41, revise the text as follows.
PS-P-15 Ensure Require adherence to applicable Diamond Bar Fire and Building Codes,
including standards for minimum road widths, and adequate access and clearance
for emergency vehicles, and the identification of all roads, streets, and major public
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-26
buildings a in a manner that is clearly visible to fire protection and other
emergency vehicles.
On page 3.7-42, revise the text as follows.
CR-P-6 Require that all new development study the impact of vehicle miles traveled (VMT)
and Continue to implement congestion mitigation measures to ensure that new
projects do not significantly increase local City congestion based on defined level
of service (LOS) standards.
On page 3.7-50, revise the text as follows.
CHS-P-27 Recognizing the adverse health impacts associated with compromised air quality,
ensure the protection of sensitive receptors from exposure to hazardous
concentrations of air pollutants when reviewing development proposals.
On page 3.7-52, revise the text as follows.
PS-P-4 Carry out a review of City-owned critical facilities that may be vulnerable to major
earthquakes and landslides and develop programs to upgrade them.
PS-P-6 Prevent and control soil erosion and corresponding landslide risks on public
property and in conjunction with new private development through hillside
protection and management.
On page 3.7-53, revise the text as follows.
PS-P-13 As resources become available, Rreduce the flooding impact of a storm event by
enhancing the city's green infrastructure system to complement the gray
infrastructure system where feasible.
LU-P-56 Ensure that development on privately-owned, residentially designated land in
hillside areas is compatible with surrounding natural areas by promoting the
following design principles requiring that development:
a. Minimizes as articulated by the landform grading criteria of the
Hillside Management regulations Ordinance
excavation, grading, and earthwork to retain natural vegetation and
topography;
b. Preserves existing vistas of significant hillside features such as ridgelines,
particularly from public places;
c. Does not create unsafe conditions;
d. Incorporate site and architectural designs that are and is sensitive to natural
contours and land forms and in its site design, including hydrological features;
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-27
e. Preserves natural watersheds, including existing vegetation within
undeveloped hillside areas to the maximum extent feasible, including mature
trees and native plant materials;
f. Permits Incorporate fuel modification as part of the Fire
approved fuel modification program;
g. Utilizes planting palettes consisting of drought tolerant, fire resistant, non-
invasive plants that are native to or compatible with those colors similar to
those of native materials in the surrounding area; and
h. Groups plants within swale areas to more closely reflect natural conditions
within landform graded slopes.
Chapter 3.8: Hydrology and Water Quality
On page 3.8-5, revise Figure 3.8-1 to remove the beige shading for the City of Diamond Bar in the
legend as follows.
!(T
Walnut
Pomona
Industry
LOS ANGELES
COUNTY
ORANGE COUNTY
SAN BERNARDINO
COUNTY
Metrolink
Station
}}}60
}}}57
}}}60
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500 Year Floodplain(0.2% Annual Chance Flood Hazard)
Highways
Ramps
Major Roads
Local Roads
Railroads
Lakes/Ponds
City of Diamond Bar
Sphere of In uence
County Boundar y
5.157.000.375
MILES
Source: FEMA's NFHL Viewer, Effective Map Date 2008;
City of Diamond Bar 2019; Dyett & Bhatia, 2019Ri versideMetrolinkLineFigure 3.8-1: FEMA F lood Insurance
Rate Map
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-29
On page 3.8-17, revise the text as follows.
LU-P-42 Avoid expanses of surface parking and requirencourage the consolidation and
location of parking to the rea r or side of buildings where appropriate.
LU-P-56 Ensure that development on privately-owned, residentially designated land in
hillside areas is compatible with surrounding natural areas by promoting the
following design principles requiring that development:
a. Minimizes as articulated by the landform grading criteria of the
Hillside Management regulations Ordinance
excavation, grading, and earthwork to retain natural vegetation and
topography;
b. Preserves existing vistas of significant hillside features such as ridgelines,
particularly from public places;
c. Does not create unsafe conditions;
d. Incorporate site and architectural designs that are and is sensitive to natural
contours and land forms and in its site design, including hydrological features;
e. Preserves natural watersheds, including existing vegetation within
undeveloped hillside areas to the maximum extent feasible, including mature
trees and native plant materials;
f. Permits Incorporate fuel modification as part of the Fire
approved fuel modification program;
g. Utilizes planting palettes consisting of drought tolerant, fire resistant, non-
invasive plants that are native to or compatible with those colors similar to
those of native materials in the surrounding area; and
h. Groups plants within swale areas to more closely reflect natural conditions
within landform graded slopes.
On page 3.8-18, revise the text as follows.
RC-P-25. Control and improve the quality of stormwater entering local water bodies by
requiring new development to incorporate best management practices (BMPs),
and Low Impact Development (LID) strategies that support on -site retention,
detention, and/or treatment of stormwater through means such as infiltration,
evapotranspiration, biofiltration, and rainfall harvest and use.
RC-P-26. Require the implementation of a stormwater pollution prevention plan (SWPPP),
and inspection by a Construction General Permit Qualified SWPPP Practitioner
(QSP), during construction and post construction to limit land disturbance
activities such as clearing and grading and cut -and-fill; avoid steep slopes, unstable
areas, and erosive soils; and minimize disturbance of natural vegetation and other
physical or biological features important to preventing erosion or sedimen tation.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-30
RC-P-273. Require Ensure that post-development peak stormwater runoff discharge rates do
not exceed the estimated pre-development rate and that dry weather runoff from
new development not exceed the pre-development baseline flow rate to receiving
water bodies.
On page 3.8-21, revise the text as follows.
RC-P-16. As opportunities arise, cCoordinate with local water agencies to encourage and
expand the use of reclaimed water, stored rainwater, or household gray water for
irrigation and other appropria te uses and consider construction of dual water
systems, where feasible, for development
RC-P-18. Carry out a comprehensive public outreach program to educate residents and
businesses about water conservation, stormwater pollution prevention, and water
reuse opportunities and advantages.
RC-P-198. Require Ensure new development to reduce the waste of potable water through the
use of drought -tolerant plants, efficient landscape design and application, and
reclaimed water systems where available.
RC-P-20 19. Require Encourage the implementation of the latest water conservation
technologies into new developments.
RC-P-21 20. Require Ensure developers builders to provide information to prospective buyers
or tenants within the City of Diamond Bar regarding drought -tolerant planting
concepts.
RC-P-22. Require the use of mulch in landscape areas to improve the water holding capacity
of the soil by reducing evaporation and soil compaction in accordance with the
-Efficient Landscape
Ordinance.
PF -P-410 As resources become available, seek cooperation Work with the LACFCD to
complete a drainage master plan for Diamond Bar with a view to identifying any
date it
periodically, as needed.
On page 3.8-22, revise the text as follows.
CHS-P-59 As resources become available, Iincrease the efficiency of water usage in public
places, such as irrigation in public parks, and utilize drought -tolerant landscaping
in City parks and streetscapes.
Final Environmental Impact Report for the Diamond Bar Draft General Plan 2040 and Draft Climate Action Plan
Chapter 4: Revisions to the Draft EIR
4-31
On page 3.8-23, revise the text as follows.
LU-P-6 When appropriate, rRequire new development t o pay its fair share of the public
facilities and off-site improvements needed to serve the proposed use.
LU-P-22 Encourage Require commercial development to incorporate outdoor green spaces
appropriate and usable for patrons and visitors.
LU-P-42 Avoid expanses of surface parking and requirencourage the consolidation and
location of parking to the rear or side of buildings where appropriate.
LU-P-45 Prepare Require that a master plan or specific plan be prepared for any future
development within the Community Core overlay area that creates a master-
planned mixed-use, pedestrian-oriented community and regional destination.
Approximately 100 acres north of Grand Avenue is to support a park or
consolidated golf course along with additional community or civic u ses. The
southern portion is to accommodate a mix of uses emphasizing destination and
specialty retail, dining, and entertainment, including opportunities for residential,
hospitality, and community and civic uses.
On page 3.8-24, revise the text as follows.
PF -P-7 Work with the Federal Emergency Management Agency (FEMA) as needed to
ensure that the City's floodplain information is up to date with the latest available
hydrologic and hydraulic engineering data.
On page 3.8-25, revise the text as follows.
PS-P-13 As resources become available, Rreduce the flooding impact of a storm event by
enhancing the city's green infrastructure system to complement the gray
infrastructure system where feasible.
Chapter 3.9: Land Use and Housing
On page 3.9-20, revise the text as follows.
LU-G-16 Create a well -designed, walkablepedestrian-friendly, mixed-use neighborhood
that encourages community interaction and healthy lifestyles while reducing
reliance on automobiles.
LU-P-7 As larger vacant or underutilized sites within the built environment are developed
or redeveloped, maximize multimodal accessibility withby requiring appropriately
designed street networks, and walkable block sizes scaled to proposed uses.
LU-P-39 Provide s Streetscape and intersection improv ements along the major corridors of
South Diamond Bar Boulevard and Golden Springs Drive toshould enhance
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connectivity, comfort, and safety for all modes of travel, and increase accessibility
to and from surrounding areas.
LU-P-40 Study, as necessary, the implementation of safe pedestrian connectivity between
the north and south sections of the Town Center Mixed -Use project site and at
Lorbeer Middle School.
Potential strategies for achieving safe pedestrian connectivity may include traffic
calming measures along the roadways, crosswalk visibility improvements, ensuring
adequate time for walk signals, refuge islands, bulb -outs, bridges, and others.
On page 3.9-21, revise the text as follows.
CR-P-32 ProvidePromote pedestrian and bicycle connectivity in existing residential
neighborhoods, utility easements, and/or flood control channels, including
connections through cul -de-sacs to other streets or community facilities where
feasible.
CR-P-38 If warranted by demand, sStudy the feasibility of implementi ng a bike share
program to connect neighborhoods and major destinations, such as the Transit -
Oriented, Neighborhood, Town Center, and Community Core Overlay mixed -use
areas; local schools and colleges; parks; and commercial centers.
On page 3.9-32, revise the text as follows.
LU-P-33 Consider amendments to the Amend Development Code parking regulations in
Title 22: Development Code of the Municipal Code as needed to allowrequire
lower parking minimums for developments with a mix of uses with different peak
parking needs, as well as developments that implement enforceable residential
parking demand reduction measures, such as parking permit and car share
programs.
LU-P-52 When opportunities arise, Ccollaborate with public service providers and agencies
including, but not limited to, the Los Angeles County Department of Parks and
Recreation, Walnut Valley and Pomona school districts, Los Angeles County
Sheriff's Department, Los Angeles County Fire Department, and Walnut Valley
Water District to designate and pu rsue acquisition of land for public facilities as
necessary to serve unmet facility needs of Diamond Bar residents.
LU-P-56 Ensure that development on privately-owned, residentially designated land in
hillside areas is compatible with surrounding natural a reas by promoting the
following design principles requiring that development:
a. Minimizes as articulated by the landform grading criteria of the
Hillside Management regulations Ordinance
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excavation, grading, and earthwork to retain natural vegetation and
topography;
b. Preserves existing vistas of significant hillside features such as ridgelines,
particularly from public places;
c. Does not create unsafe conditions;
d. Incorporate site and architectural designs that are and is sensitive to natural
contours and land forms and in its site design, including hydrological features;
e. Preserves natural watersheds, including existing vegetation within
undeveloped hillside areas to the maximum extent feasible, including mature
trees and native plant materials;
f. Permits Incorporate fuel modification as part of the Fire
approved fuel modification program;
g. Utilizes planting palettes consisting of drought tolerant, fire resistant, non-
invasive plants that are native to or compatible with those colors similar to
those of native materials in the surrounding area; and
h. Groups plants within swale areas to more closely reflect natural conditions
within landform graded slopes.
On page 3.9-23, revise the text as follows.
LU-P-18 Require dDevelopment toshould be sensitive to the building form, density,
massing, and scale of surrounding residential neighborhoods.
LU-P-23 Residential and mixed -use developments on For sites larger than two acres in size
should include , require the construction of a range of housing types that meet the
needs of a diversity of income levels and household sizes.
CH-P-11 Evaluate and make changes to the project review and permitting process to
eEncourage and facilitate incorporation of universal lifecycle design principles
(design that promotes the ability to remain in one's house as one ages) in new
residential development, allowing community members to stay in their homes and
neighborhoods longer.
Chapter 3.10: Noise
On page 3.10 -33, revise the text as follows.
PS-P-49 RequireEnsure that detailed site-specific noise analysis, including the
identification of noise mitigation measures, be prepared for all development
proposals located where project noise exposure would be other than normally or
conditionally acceptable as specified i n Table 7 -1. With mitigation, development
should meet the allowable exterior and interior noise exposure standards
established in the Noise Control Ordinance.
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Chapter 3.11: Public Facilities and Recreation
On page 3.11-13, revise the text as follows.
Table 3.11-6: Existing and Proposed Trail Network (2019)
Existing Trails Miles
Pantera Park Trail 0.60
Peterson Park Trail 0.29
Schabarum Trail (Skyline Extension) 7.94
Summitridge Trail 0.98
Summitridge Trail (Alternate Route) 0.61
Summitridge Trail (Canyon Route) 0.52
Summitridge Trail (Ridge Route) 0.62
Sycamore Canyon Park Trail 0.92
Tonner Canyon Trail 3.84
Subtotal: Existing Trails 16.31 4.53
Proposed Trails Miles
Crooked Creek Trail Head 0.31
Larkstone Park Trail 0.44
Sandstone Canyon Trail Lower 0.79
Sandstone Canyon Trail Upper 1.80
Sandstone Canyon Trail Upper (Alt) 0.46
Schabarum Trail (Skyline Extension) 7.94
Tonner Canyon Trail 3.84
Subtotal: Proposed Trails 3.81 15.59
Total Existing Plus Proposed Trails 20.11
Source: City of Diamond Bar Parks and Recreation Master Plan, 2011, Dyett and Bhatia, 2019.
On page 3.11 -14, revise the text as follows.
The trail allows recreational users and commuters hikers, mountain bikers, and equestrians to
connect to a variety of other trails in the area, such as those in the Peter F. Schabarum Regional
Park and Puente Hills Nature Preserve, as well as the San Gabriel and Rio Hondo River Trails.2
2 The development of staging areas and trailheads will be considered at strategic locations to
accommodate multi-use trail users.
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On page 3.11 -28, revise the text as follows.
LU-P-6 When appropriate, rRequire new development to pay its fair share of the public
facilities and off-site improvements needed to serve the proposed use.
LU-P-19 To meet the recreational needs of new residents , Require ensure that new
residential and mixed-use developments larger than four acres to incorporate
public parkland in the neighborhoods where such developments are located.
Residential and mixed-use developments under four acres may Require other
development to provide dedicated parkland, in lieu fees for sites under four acres,
or a combination, in accordance with Diamond Bar's park acreage standards, to
meet the recreational needs of new residents.
LU-G-27 Designate adequate and equitably-distributed land throughout the community for
educational, cultural, recreational, and public service activities to meet the needs
of Diamond Bar residents.
LU-P-52 When opportunities arise, Ccollaborate with public service providers and agencies
including, but not limited to, the Los Angeles County Department of Parks and
Recreation, Walnut Valley and Pomona school districts, Los Angeles County
Sheriff's Department, Los Angeles County Fire Department, and Walnut Valley
Water District to designate and pursue acquisition of land for public facilities as
necessary to serve unmet facility needs of Diamond Bar residents.
LU-P-56 Ensure that development on priva tely-owned, residentially designated land in
hillside areas is compatible with surrounding natural areas by promoting the
following design principles requiring that development:
a. Minimizes as articulated by the landform grading criteria of the
Hillside Management regulations Ordinance
excavation, grading, and earthwork to retain natural vegetation and
topography;
b. Preserves existing vistas of significant hillside features such as ridgelines,
particularly from public places;
c. Does not create unsafe conditions;
d. Incorporate site and architectural designs that are and is sensitive to natural
contours and land forms and in its site design, including hydrological features;
e. Preserves natural watersheds, including existing vegetation within
undeveloped hillside areas to the maximum extent feasible, including mature
trees and native plant materials;
f. Permits Incorporate fuel modification as part of the Fire
approved fuel modification program;
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g. Utilizes planting pal ettes consisting of drought tolerant, fire resistant, non-
invasive plants that are native to or compatible with those colors similar to
those of native materials in the surrounding area; and
h. Groups plants within swale areas to more closely reflect natural conditions
within landform graded slopes.
On page 3.11 -30, revise the text as follows.
CR-P-5 Require nNecessary transportation improvements toshould be in place, or
otherwise guaranteed to be installed in a timely manner, before or concurrent with
new development. In evaluating whether a transportation improvement is
necessary, consider alternatives to the improvement consistent with CR -G-1, and
the extent to which the improvement will offset the traffic impacts generated by
proposed and expected development.
CR-P-6 Require that all new development study the impact of vehicle miles traveled (VMT)
andContinue to implement congestion mitigation measures to ensure that new
projects do not significantly increase local City congestion based on defined level
of service (LOS) standards.
On page 3.11 -31, revise the text as follows.
RC-P-1 As opportunities arise, Oobtain and designate open space land through acquisition
techniques such as:
a. Requiring the incorporation of Incorporating open space and recreational
areas into the design of new development projects, preserving and enhancing
as open space significant stands of vegetation, natural landforms, and any areas
of special ecological significance through site design approaches such as
clustering and ecological planning.
b. Allowing clustering or transferring of all or part of the development potential
of a site to a portion of the site to preserve significant environmental resources
such as natural and native habitats (oak woodland, coastal sage scrub, etc.),
natural creeks, artesian springs, vernal pools, seeps, riverines, wetlands,
riparian habitats, wildlife corridors and linkages, and natural geological
features within proposed developments as open space.
c. Allowing for acquisition of open space lands through the ent itlement process
and the transfer of densities among land uses of like designation.
d. Collaborating with land trusts and other conservation groups to acquire open
space land through, but not limited to, conservation easements.
RC-P-6 DevelopUpdate, as appropriate, standards for planning, design, management, and
maintenance of trails and pathways within parks, preserves, open space, and rights -
of -way.
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RC-P-8 WorkTo the extent feasible, support and cooperate with the efforts of other
jurisdictions and conservation organizations to protect prominent ridges, slopes,
and hilltops in and adjacent to the City and its Sphere of Influence.
Such features include, but are not limited to, areas identified by Los Angeles County
as Significant Ecological Areas; Tonner Canyon; the hills within Tres Hermanos
Ranch; and the hillsides along SR-57, between Diamond Bar and Brea.
RC-P-10 Require, to the greatest extent feasible, new development to preserve mature native
trees including oak and wal nut, and trees of significant cultural or historical value
such as sycamore and arroyo willow, etc., as set forth under the Diamond Bar Tree
Preservation and Protection Ordinance. Review the ordinance periodically and
update it as necessary to reflect current best practices.
RC-P-11 Require that all development, including roads and trails, proposed adjacent to
riparian and other biologically sensitive habitats avoid , to the greatest extent
feasible, significant impacts that would undermine the healthy natural functioning
of those areas. Require that new development proposed in such locations be
designed to:
a. Minimize to the greatest extent possible or eliminate impacts on
environmentally sensitive areas;
b. Protect the visual seclusion of forage areas from road intrusion by providing
vegetative buffering;
c. Protectvide wildlife movement linkages to water, food, shelter, and nesting
sites;
d. Allow wildlife and migration access by use of tunnels or other practical means;
e. Provide vegetation that can be used by wildlife for cover along roadsides;
f. Avoid intrusion of night lighting into identified areas through properly
designed lighting systems;
g. Avoid impacts to wetlands, natural springs and seeps and maintain access for
wildlife or when natural water areas are removed or blocked provide a locally
suitable and equal replacement; and
h. To the greatest extent possible, prevent street water runoff from flowing into
waterways
RC-P-16. As opportunities arise, cCoordinate with local water agencies to encourage and
expand the use of reclaimed water, stored rainwater, or household gray water for
irrigation and other appropriate uses and consider construction of dual water
systems, where feasible, for development
RC-P-198. Require Ensure new development to reduce the waste of potable water through the
use of drought -tolerant plants, efficient landscape design and application, and
reclaimed water systems where available.
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RC-P-20 19. Require Encourage the implementation of the latest water
conservationtechnologies into new develop ments.
RC-P-25. Control and improve the quality of stormwater entering local water bodies by
requiring new development to incorporate best management practices (BMPs),
and Low Impact Development (LID) strategies that support on -site retention,
detention, and/or treatment of stormwater through means such as infiltration,
evapotranspiration, biofiltration, and rainfall harvest and use.
RC-P-39. Address impacts of new development projects that may individually have
insignificant impacts on air quality, but w hich together with other projects in the
Planning Area may be cumulative significant by establishing mitigation programs
at the area wide or citywide level.
On page 3.11 -36, revise the text as follows.
PF -G-2 Provide new parks in concert with new residential development, and strive to
distribute while ensuring that parkland is distributed equitably across throughout
the cCity.
PF -G-3 RequireEnsure that new development bears the costs of new parks and recreation
facilities that are needed to meet any increase in demand resulting from the new
development, or from which the new development would benefit.
PF -P-6 Monitor and seek to Aactively
redevelopment of the former Lanterman site, and seek joint use opportunities for
parks and recreation facilities developed on the site.
PF -P-7 Endeavor to Ddistribute new parks equitably throughout Diamond Bar, striving to
ensure that residents are within a ¾-mile radius of a neighborhood park or
community park.
PF -P-11 Where appropriate, Ppromote the joint development, use, and maintenance of
parks and open space facilities with adjacent jurisdictions, the Count y of Los
Angeles, and the State of California.
PF -P-13 When planning and designing Develop facility,public facilities and parks, design
and site planning standards that take into consideration accessibility, flexible use,
adaptability, energy and water eff iciency, ease of maintenance, and sustainable
design elements that take advantage of the natural processes of healthy ecosystems,
while preserving historic and cultural resources and sensitive habitats.
PF -P-17 Require that Address the recreational needs of all children and adults, including
persons with disabilities, seniors, and dependent adults, be addressed in
recreational facility planning efforts.
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PF -P-18 Where feasible, Llink parks, open spaces, and regional hiking trails with a trail
network. Incorporate existing trails and bicycle and pedestrian infrastructure,
working with willing landowners to prioritize land acquisition where necessary.
Where possible, incorporate landscaping and enhance natural features.
PF -P-19 Consider Updateupdating the Parks and Recreation Master Plan to include
standards for planning, design, management, and maintenance of trails and
pathways within parks, preserves, open spaces, and rightsof - way. Encourage the
installation of amenities such as rest areas, benches, water facilities, hitching posts
and wayfinding signs serving trails and scenic routes that adhere to a standard
signage palette.
PF -P-20 Strive to Mmaintain the Parks and Recreation Master Plan goal of at least one mile
of recreational trails for each 1 0,000 persons.
PF -P-22 Consider opportunities to Ppartner with non-profit organizations to assist in
developing and managing the trails system and providing community outreach
and education.
PF -P-23 Coordinate trail planning with regional trail and open s pace plans to ensure
connectivity and access to the regional trail system.
On page 3.11 -38, revise the text as follows.
PS-P-1 Require new emergency facilities subject to City land use regulations and
permitting requirements, including, but not limited to, fire stations, paramedic
services, police stations, hospitals, ambulance services, and emergency operations
centers be designed to withstand and remain in operation following the maximum
credible earthquake event.
PS-P-6 Prevent and control soil erosion and corresponding landslide risks on public
property and in conjunction with new private development through hillside
protection and management.
PS-P-13 As resources become available, Rreduce the flooding impact of a storm event by
enhancing the city's green infrastructure system to complement the gray
infrastructure system where feasible.
PS-P-15 Ensure Require adherence to applicable Diamond Bar Fire and Building Codes,
including standards for minimum road widths, and adequate access and clearance
for emergency vehicles, and the identification of all roads, streets, and major public
buildings a in a manner that is clearly visible to fire protection and other
emergency vehicles.
PS-P-49 RequireEnsure that detailed site-specific noise analysis, including the
identification of noise mitigation measures, be prepared for all development
proposals located where project noise exposure would be other than normally or
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conditionally acceptable as specified in Table 7 -1. With mitigation, development
should meet the allowable exterior and interior noise exposure standards
established in the Noise Control Ordinance.
On page 3.11 -41, revise the text as follows.
CHS-P-29 RequireIncorporate noise mitigation measures, which could include buffers, noise
barriers, or natural open space, and vegetation, between new sensitive uses such as
residential units and schools, and major noise polluters such as SR-57 and SR-60,
the Metrolink Riverside rail line, and heavy industry.
On page 3.11 -43, revise the text as follows.
RC-P-1 As opportunities arise, Oobtain and designate open space land through acquisition
techniques such as:
a. Requiring the incorporation of Incorporating open space and recreational
areas into the design of new development projects, preserving and enhancing
as open space significant stands of vegetation, natural landforms, and any areas
of special ecological significance through site design approaches such as
clustering and ecological planning.
b. Allowing clustering or transferring of all or part of the development potential
of a site to a portion of the site to preserve significant environmental resources
such as natural and native habitats (oak woodland, coastal sage scrub, etc.),
natural creeks, artesian springs, vernal pools, seeps, riverines, wetlands,
riparian habitats, wildlife corridors and linkages, and natural geological
features within proposed developments as open space.
c. Allowing for acquisition of open space lands through the entitlement proce ss
and the transfer of densities among land uses of like designation.
d. Collaborating with land trusts and other conservation groups to acquire open
space land through, but not limited to, conservation easements.
RC-P-6 DevelopUpdate, as appropriate, standards for planning, design, management, and
maintenance of trails and pathways within parks, preserves, open space, and rights -
of -way.
Chapter 3.12: Transportation
On page 3.12 -37, revise the text as follows.
CR-P-31 When updatingUpdate th e Parks and Recreation Master Plan useing community
input and best practices to identify bicycle infrastructure needs such as gaps in the
network, prioritize facilities and improvements, and identify funding for proposed
facilities. Review and update the plan as necessary.
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CR-P-32 ProvidePromote pedestrian and bicycle connectivity in existing residential
neighborhoods, utility easements, and/or flood control channels, including
connections through cul -de-sacs to other streets or community facilities where
feasible.
CR-P-34 As opportunities arise, Ccollaborate with neighboring jurisdictions and colleges
such as Cal Poly Pomona and Mt. San Antonio College to establish a safe and
efficient bicycle route between Diamond Bar and these institutions.
CR-P-38 If warranted by demand, sStudy the feasibility of implementing a bike share
program to connect neighborhoods and major destinations, such as the Transit -
Oriented, Neighborhood, Town Center, and Community Core Overlay mixed -use
areas; local schools and colleges; parks; and commercial centers.
CR-P-39 Ensure a safe environment for pedestrians and cyclists while allowing for local
traffic to access freeways in the Neighborhood Mixed Use area through the
following strategies:
a. Traffic calming measures such as reduced vehicle speed limits and road
narrowing;
a. Widening sidewalks, providing planting strips between sidewalks and streets
and providing pedestrian amenities such as shade trees and street furniture
along Diamond Bar Boulevard;
b. Implementing traffic calming measures such as reduced vehicle speeds,
striping and signageroad diets along Diamond Bar Boulevard;
c. Buffering bike lanes along Diamond Bar Boulevard;
d. Enhancing pedestrian crossings at the intersection of Diamond Bar Boulevard
and Sunset Crossing Road, at Diamond Bar Boulevard and Highland Valley
Road, and at Diamond Bar Boulevard and the SR -60 on/off ramps; and
e. Incorporating multi-use pathways internal to new development and
connecting to existing development.
CR-P-42 Develop and implement Safe Routes to School and Safe Routes for Seniors
programs in collaboration with interested stakeholders such as school districts,
senior living facilities, and community organizations to encourage active
transportation among students and seniors while ensuring student and senior
safety.
CR-P-43 When planning capital improvement programs, consider projects that Sstrengthen
the protection of cyclists in bike lanes by implementing improvements such as
increasing visibility of lane markings and signage, increasing bike lane widths,
raising lanes, designing safer intersection cr ossings and turns, and buffering lanes
from traffic wherever feasible, prioritizing bicycle lanes along arterials.
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CR-G-13 MaximizeSupport the availability, efficiency, and effectiveness of Integrate transit
nodes and connections with adjacent existing and proposed developments and
destinations such as employment centers, commercial centers, major attractions,
and public pedestrian spaces to make them more accessible to transit users.
CR-P-46 Where feasible, Iintegrate transit nodes and connections with adj acent existing and
proposed developments and destinations such as employment centers,
commercial centers, major attractions, and public pedestrian spaces to make
them more accessible to transit users.
CR-P-47 As opportunities arise, Ccoordinate with Foothill Transit, Metrolink, and other
transit providers to incorporate real -time information systems at transit stops so
that passengers will know when their vehicle is expected to arrive.
CR-P-48 As opportunities arise, Wwork with Foothill Transit to maintain and improve bus
stops and shelters, as well as identify areas where service can be improved or
expanded to increase system use.
CR-P-50 As opportunities arise, Ccoordinate with Metrolink and Union Pacific Railroad
(UPRR) to provide more frequent service at the City of Industry station, including
service for shorter trips, to increase the convenience and use of transit.
CR-P-51 Continue to sSupport, where feasible, privately funded local transit systems that
are accessible for seniors, youths, and individual s with disabilities, to ensure that
all community members have the ability to travel while decreasing congestion.
On page 3.12 -33, revise the text as follows.
CR-P-1 When redesigning streets, plan for the needs of different modes by incorporating
considering elements such as shade for pedestrians, safe pedestrian -friendly
crossings/intersections, lighting at the pedestrian scale, bike lanes, signage visible
to relevant modes, transit amenities, etc.
CR-P-2 Require that Promote new street designs and efforts to retrofit existing streets in
residential neighborhoods minimize traffic volumes and/or speed as appropriate
without compromising connectivity for emergency vehicles, bicycles, pedestrians,
and users of mobility devices.
CR-P-6 Require that all new development study the impact of vehicle miles traveled (VMT)
and Continue to implement congestion mitigation measures to ensure that new
projects do not significantly increase local City congestion based on defined level
of service (LOS) standards.
CR-P-7 Support the Ddevelop ment of City street design standards that:
a. Address the needs of different modes according to roadway classification;
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b. Reduce the potential for conflicts and safety risks between modes; and
c. Support and manage the use of transportation options that will become
increasingly popular in the future, such as TNCs, AVs, micro-transit (privately
operated transit), and other emerging transportation technologies.
CR-P-22 Implement traffic calming measures to slow traffic on local and collector
residential streets and prioritize these measures over congestion management
where appropriate and feasible.
CR-P-24 As opportunities arise, cCoordinate with local, regional, and State agencies to
encourage and support programs that reduce vehicle miles traveled, such as
preferential carpool and car share parking, parking pricing, on -site childcare,
flexible work schedules, subsidized transit p asses, and ridesharing.
CR-P-26 As opportunities arise, Ccoordinate with other jurisdictions, including
neighboring cities, Los Angeles County, San Bernardino County, and Caltrans, on
improvements to street segments common to the City of Diamond Bar and other
jurisdictions.
CR-P-53 UpdateConsider updating parking standards in the Municipal Development Code
parking demand and taking into consideration demographics and access to
alternative modes of transportation.
CR-P-54 Consider incorporatingIncorporate criteria in the MunicipalDevelopment Code to
allow reductions in parking requirements in exchange for VMT reduction
measures.
CR-P-55 Consider the establishment of Incorporate common bicycle parking requirements
for appropriate uses including multi-family residential and office in the
Municipal Code.
CR-P-57 Consider incentives to encourage carpooling, such as Incentivize the provision of
preferential parking for high-occupancy vehicles to encourage carpooling.
CR-P-59 As opportunities arise, Wwork with Caltrans to evaluate existing Caltrans -
operated park-n-ride facilities within the City and expand the facilities where
necessary.
On page 3.12 -36, revise the text as follows.
CR-P-62 Revise the designation of truck routes to minimize truck traffic through or near
residential areas. Maintain truck routes with signage between industrial areas and
freeway interchanges to discourage truck travel through residential
neighborhoods, and provide truck route information to truck routing software
providers.
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Chapter 3.13: Utilities and Service Systems
On page 3.13 -24, revise the text as follows.
LU-P-6 When appropriate, rRequire new development to pay its fair share of the public
facilities and off-site improvements needed to serve the proposed use.
LU-P-52 When opportunities arise, Ccollaborate with public service providers and agencies
including, but not limited to, the Los Angeles County Department of Parks and
Recreation, Walnut Valley and Pomona school districts, Los Angeles County
Sheriff's Department, Los Angeles County Fire Department, and Walnut Valley
Water District to designate and pursue acquisition of land for public facilities as
necessary to serve unmet facility needs of Diamond Bar residents.
PF -P-310 Require, when appropriate, the construction of water, sewer, drainage, and other
necessary public facilities, and encourage storm water capture prior to or
concurrent with new development.
PF -P-376 Support and take part inCollaborate with
plans to expand the use of recycled water within Diamond Bar as additional
recycled water supplies become available.
PF -P-410 As resources become a vailable, seek cooperationWork with the LACFCD to
complete a drainage master plan for Diamond Bar with a view to identifying any
periodically, as needed.
On page 3.13 -26, revise the text as follows.
PF -P-365 Work withSupport the Walnut Valley Water District (WVWD) in efforts to assess
the condition of water distribution and storage systems within Diamond Bar and
plan for refurbishments as needed.
On page 3.13 -27, revise the text as follows.
PF -P-387 As opportunities arise, Wwork with the Los Angeles County Public Works
Department (LACPWD) and Los Angeles County Sanitation District (LACSD) to
ensure that wastewater treatment conveyance systems and treatment facility
capacity is available to serve planned development within Diamond Bar.
On page 3.13 -30, revise the text as follows.
CHS-P-52 Support and cooperate with County and State regulatory agency efforts to Rrequire
commercial and industrial generators to develop and implement a source
reduction and recycling plan tailored to their individual waste streams.