HomeMy WebLinkAboutRES 2026-05RESOLUTION NO, 2026-05
A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF DIAMOND
BAR, CALIFORNIA, CERTIFYING THE FINAL SUPPLEMENTAL
ENVIRONMENTAL IMPACT REPORT (SCH NO. 2018051066), AND
ADOPTING FINDINGS OF FACT, A STATEMENT OF OVERRIDING
CONSIDERATIONS, AND A MITIGATION MONITORING AND
REPORTING PROGRAM FOR THE TOWN CENTER SPECIFIC PLAN.
WHEREAS, on December 17, 2019, the City Council adopted the Diamond Bar
General Plan 2040 ("General Plan") and the Climate Action Plan 2040 ("CAP") to create
a vision and blueprint for development through 2040. The Diamond Bar General Plan
2040 establishes the Town Center Mixed -Use, Neighborhood Mixed -Use, Transit
Oriented Mixed -Use, and Community Core Overlay focus areas and corresponding land
use designations, estimates that up to 3,750 new housing units could be built in the city
by 2040, and anticipates that much of this growth will occur within these four focus
areas.
WHEREAS, on August 11, 2022, the City Council adopted the City's 2021-2029
General Plan Housing Element ("2021-2029 Housing Element" or "6t" Cycle Housing
Element"), which was subsequently found by the California Department of Housing and
Community Development (HCD) to be in full compliance with State Housing Element Law
(Article 10.6 of the Gov. Code) on October 5, 2022. The 2021-2029 Housing Element
identifies sites to accommodate the City's Regional Housing Needs Allocation (RHNA) of
2,516 residential units, including through rezoning of underutilized sites in the Town
Center Mixed -Use, Neighborhood Mixed -Use, Transit Oriented Mixed -Use focus areas to
allow residential development at a minimum density of 20 dwelling units per acre and a
maximum density of at least 30 dwelling units per acre.
WHEREAS, in conjunction with the adoption of the General Plan and the CAP, the
City, as lead agency, prepared an Environmental Impact Report, State Clearinghouse
Number 2018051066, to analyze the potential environmental impacts of those plans (the
"EIR"). The City Council certified the EIR on December 17, 2019, and the City filed a
Notice of Determination on December 18, 2019. In conjunction with the adoption of the
2021-2029 Housing Element, the City, as lead agency, evaluated the potential
environmental impacts of the Housing Element in an addendum to the EIR, and the City
Council adopted the addendum on August 11, 2022.
WHEREAS, on January 27, 2025, the City Council adopted Resolution No. 2025-
04 approving an amendment to the Land Use Element of the General Plan to establish a
minimum residential density of 20 dwelling units per acre and a maximum residential
density of 30 dwelling units per acre on sites within the Town Center Mixed -Use and
Neighborhood Mixed -Use Land Use Designations.
WHEREAS, on February 4, 2025, the City Council adopted Ordinance No. 01
(2025), establishing the housing element site (H) overlay district to provide development
and land use regulations for the development of multifamily dwellings on specified sites
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identified in the City of Diamond Bar 2021-2029 Housing Element to accommodate the
City's RHNA requirements. The Zoning Map was concurrently amended to apply the H
overlay district designation to those parcels with a General Plan land use designation of
Town Center Mixed -Use, Neighborhood Mixed -Use, and Transit -Oriented Mixed -Use.
The H overlay district establishes a maximum residential density of 30 dwelling units per
acre. Because the H overlay district implements the densities established in the General
Plan Land Use Element and required by the 2021-2029 Housing Element for the Town
Center Mixed -Use, Neighborhood Mixed -Use, Transit Oriented Mixed -Use focus areas,
the City Council determined that the rezoning of the specified sites would not result in any
new significant impacts or a substantial increase in the severity of previously identified
significant impacts; therefore, no further environmental analysis was required. (Public
Resources Code § 21166; CEQA Guidelines §§ 15168, 15162.)
WHEREAS, the Town Center Mixed Use land use designation ("Town Center" or
"Planning Area") consists of approximately 45 acres, bounded on the north by the
Pomona Freeway (State Route [SR] 60), on the east by a neighborhood of single-family
homes, on the south by Lorbeer Middle School and Mount Calvary Lutheran Church and
School, and on the west by the Fall Creek private condominium community. The Planning
Area is composed of 35 individual parcels with 23 unique property owners within a
suburban -style commercial district. The Planning Area is centered around Diamond Bar
Boulevard, a six -lane thoroughfare with painted bike lanes, that bisects the Town Center
and extends over 1,800 feet. It is bounded on the south by Golden Springs Drive for
approximately 1,600 feet and on the north by the SR-60 Freeway. Access to the Town
Center is provided by both SR-60 and SR-57. Travelling on SR-60, access to the Town
Center can be attained by Diamond Bar Boulevard (Exit 26).
WHEREAS, the Land Use and Economic Development Element of the General
Plan established the Town Center Mixed -Use land use designation to transform a
suburban style, auto -oriented neighborhood commercial area into a "vibrant, pedestrian -
oriented Town Center in Diamond Bar" to "encourage a mix of uses with an emphasis on
community -serving and destination retail, dining, and entertainment uses, in addition to
offices, professional services, and residential uses.
WHEREAS, in July 2022, the City initiated preparation of the Town Center Specific
Plan ("TCSP") to implement the vision, goals and policies set forth in the General Plan,
as well as the recommended land use strategies published in the Urban Land Institute -
Los Angeles CULI-LA") Technical Assistance Panel ("TAP") Report, published in April
2021. One of the TAP Report's key recommendations was to accommodate a residential
buildout of more than 2,000 dwellings units in the Town Center, or approximately 700
more dwelling units than what a base density of 30 dwelling units per acre would yield
under the current General Plan and zoning designations.
WHEREAS, the TCSP will establish a regulatory framework to guide the
transformation of the Town Center from the existing suburban -style retail shopping
centers into a pedestrian -oriented downtown, providing housing opportunities, retail,
restaurants, and entertainment uses within the City of Diamond Bar. Implementation of
the TCSP is anticipated to result in the development of up to 2,055 housing units (an
increase of 705 units); 200 hotel rooms (an increase of 103 rooms); 40,000 square feet
2
of public open space an increase of 40,000 square feet); and 446,000 square feet of
commercial space (a net decrease of 64,000 square feet), including retail, dining, and
entertainment uses, as compared to development anticipated for the area under the
General Plan, as amended by the 2021-2029 Housing Element. This proposed increase
in density is consistent with the major conclusions TAP report, which found that higher
residential densities are appropriate for achieving a viable, mixed -use Town Center.
Supporting infrastructure and development standards will be implemented through the
TCSP and associated entitlements.
WHEREAS, approval and implementation of the TCSP requires City Council
adoption of concurrent legislative actions, including a General Plan amendment and an
ordinance to amend the Official Zoning Map and Title 22 of the Diamond Bar City Code
("Development Code") to establish the TCSP as the regulatory document governing the
Town Center. These actions would revise the General Plan criteria and the zoning
designation applicable to the Planning Area as necessary to ensure consistency with, and
implementation of, the TCSP's framework, including maximum residential density and
permitted uses. The General Plan Amendment, TCSP, and amendments to the Official
Zoning Map and the Development Code collectively constitute the "Project."
WHEREAS, the City of Diamond Bar ("City") is the Lead Agency for the Project,
as defined by Section 21067 of the California Environmental Quality Act ("CEQA")
Statutes (Public Resources Code Section 21000 et seq.).
WHEREAS, the City determined that the appropriate environmental document for
the Project would be a Supplemental Environmental Impact Report ("SIR") to the certified
General Plan and CAP Program EIR ("Certified EIR"), as addended on August 11, 2022
with adoption of the 2021-2029 Housing Element Update.
WHEREAS, the SIR supplements the previously certified 2019 General Plan and
CAP Program EIR, as addended, which remains operative except as moed by the SIR.
WHEREAS, on June 5, 2023, the City disseminated a Notice of Preparation
("NOP") to solicit comments on the scope and content of the SIR. The NOP was sent to
the California Office of Land Use and Climate Innovation State Clearinghouse ("SCH"),
the Los Angeles County Clerk of the Board, and to responsible and trustee agencies;
noticed in the San Gabriel Valley Tribune; mailed to interested stakeholders, property
owners and business owners within a 1,000400t radius of the Planning Area, inclusive of
the Planning Area; and emailed to individuals who subscribed to receive TCSP
notifications. The NOP was circulated for a 30-day review period that commenced on
June 5, 2023, and ended on July 5, 2023.
WHEREAS, On June 8, 2023, as part of the scoping process, a Scoping meeting
was held at Diamond Bar City Hall, 21810 Copley Drive, Diamond Bar, California, during
which 30 verbal comments were received and incorporated where appropriate into the
Draft SIR.
WHEREAS, five public agencies and two individuals submitted written comments
on the NOP. These comments were considered and incorporated where appropriate into
the Draft SIR.
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WHEREAS, a Draft SIR was prepared, incorporating all of the mandated contents
set forth pursuant to CEQA Guidelines Section 15120 et seq.
WHEREAS, on August 25, 2025, upon completion of the Draft SIR, a Notice of
Completion ("NOC") was filed with SCH, and a Notice of Availability ("NOX) was filed
with the County of Los Angeles Clerk of the Board, as required by Public Resources Code
Section 21092. Pursuant to CEQA Guidelines Section 15087, the City also sent the NOA
to anyone requesting it. The NOA was also published in the San Gabriel Valley Tribune
on August 25 and September 8, 2025, and copies were mailed to 910 interested parties,
property owners and business owners within a 1,000400t radius of the Planning Area,
inclusive of the Planning Area. The Draft SIR was concurrently made available for public
review on the City's dedicated TCSP website (www.downtown4db.com), and hardcopies
were made available for public review at City Hall (21810 Copley Drive, Diamond Bar, CA
91765) and at the Diamond Bar Public Library (21800 Copley Drive, Diamond Bar, CA
)1765).
WHEREAS, the State -mandated public review period for the Draft SIR is 45 days.
The public review period ran for a total of 46 days, from August 25, 2025 to October 10,
2025.
WHEREAS, a total of 28 comment letters and emails were on the Draft SIR during
the public review period from public agencies, public interest organizations and
individuals.
WHEREAS, after receiving public comments on the Draft SIR, the City prepared a
Final SIR for the TCSP. The Final SIR includes the written comments received on the
Draft SIR and the City's responses thereto. The Final SIR identifies minor revisions to the
Draft SIR and TCSP made in response to comments received on the Draft SIR, as well
as minor corrections to the documents that have been identified by City staff.
WHEREAS, a Mitigation Monitoring and Reporting Program ("MMRP") was
prepared in conformance with Public Resources Code Section 21081.6(a)(1) and is
attached hereto as Exhibit 1 and hereby incorporated by reference.
WHEREAS, findings of Fact and a Statement of Overriding Considerations
("FOF/SOC") were prepared in conformance with CEQA Guidelines Sections 15091 and
15093 and are attached hereto as Exhibit 2 and hereby incorporated by reference.
WHEREAS, on February 5, 2026, the Final SIR, MMRP and FOF/SOC were
uploaded to the TCSP website, and hardcopies were made available for public review at
City Hall and at the Diamond Bar Public Library.
WHEREAS, on February 10, 2026, the Planning Commission of the City of
Diamond Bar conducted a duly noticed public hearing regarding the Project, solicited
testimony from all interested individuals regarding the Project, the SIR, the MMRP, and
the FOF/SOC, and concluded said hearing on that date.
WHEREAS, all legal prerequisites to the adoption of this resolution have occurred.
0
WHEREAS, the documents and materials constituting the administrative record of
the proceedings upon which the City's decision is based are located at the City of
Diamond Bar, Community Development Department, Planning Division, 21810 Copley
Drive, Diamond Bar, CA 91765.
NOW, THEREFORE, BE IT RESOLVED by I Council of the City of
Diamond Bar, as follows:
Section 1. That all of the facts set forth in the Recitals, Part A, of this Resolution
are true and correct.
Section 2. The City Council hereby adopts the findings of fact attached hereto
as Exhibit 2.
Section 3. The City Council hereby adopts the mitigation monitoring and
reporting program attached hereto as Exhibit 1.
Section 4. That with the implementation of the identified mitigation measures,
all potentially significant impacts will be reduced to a level of less than significant with the
exception of the following:
a. Air Quality (Operational Emissions) — Construction -related emissions would be
below South Coast Air Quality Management District ("SCAQMD") significance
thresholds with implementation of mitigation measures. However, operation of the
TCSP would result in a cumulatively considerable net increase in criteria pollutants
for which the region is in nonattainment. As shown in Tables 3.2.7 and 3.2-8 of the
SIR, operational emissions of reactive organic gases (ROG), nitrogen oxides
(NOx), carbon monoxide (CO), particulate matter (PM2.5), and particulate matter
(PM10) would exceed applicable SCAQMD significance thresholds. Accordingly,
operational air quality impacts would remain significant and unavoidable. [Impact
3.2.2]
b. Air Quality (Sensitive Receptors) — Construction -related impacts to sensitive
receptors would be below SCAQMD signcance thresholds with mgation.
However, operation of the TCSP would expose sensitive receptors to pollutant
concentrations associated with operational emissions of ROG, NOx, CO, PM2.5,
and PM10 at levels exceeding SCAQMD thresholds. Accordingly, operational
impacts to sensitive receptors would remain significant and unavoidable. [Impact
3.2.3]
c. Transportation —Implementation of the Proposed Project would conflict or be
inconsistent with CEQA Guidelines Section 15064.3, Subdivision (b). [Impact
3.8.1]
Section 5. That the Statement of Overriding Considerations has identified the
specific economic, legal, social, technological, or other benefits that override each of the
significant and unavoidable impacts associated with the implementation of the TCSP.
The City Council hereby adopts the statement of overriding considerations set forth in
Exhibit 2 attached hereto.
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Section 6. The City Council hereby certifies the SIR, consisting of the Draft SIR,
all related technical appendices, and the Final SIR, as complete and adequate. The City
Council finds that:
a. The SIR has been prepared and completed in compliance with CEQA (Public
Resources Code §21000 et seq.) and the State CEQA Guidelines;
b. The City Council has reviewed and considered the information contained in the
SIR prior to approving the Project; and
c. The SIR reflects the City's independent judgment and analysis.
Section 7. The City Clerk shall attest and certify to the passage and adoption of
this Resolution and enter it into the book of original resolutions, and it shall become
effective immediately upon its approval.
PASSED, APPROVED AND ADOPTED this 3�d day of March, 2026.
CITY OF DIAMOND BAR
ATTEST
I, Kristina Santana, City Clerk of the City of Diamond Bar, do hereby certify that the
foregoing Resolution was duly and regularly passed, approved and adopted by the City
Council of the City of Diamond Bar, California, at its regular meeting held on the 3rd day of
March, 2026, by the following vote:
AYES: COUNCIL MEMBERS:
NOES: COUNCIL MEMBERS:
ABSENT: COUNCIL MEMBERS:
ABSTAIN: COUNCIL MEMBERS:
Chou, Liu, Teng, MPT/Low, M/Tye
None
None
None
Kristina Santana, City Clerk
Attachment: Exhibit 1 —Mitigation Monitoring and Reporting Program
Exhibit 2 —Findings of Fact and Statement of Overriding
Considerations
L
Exhibit 1
DIAMOND BAR TOWN CENTER SPECIFIC PLAN
MITIGATION MONITORING AND REPORTING PROGRAM
SCH No. 2018051066
PREPARED FOR:
CITY OF DIAMOND BAR
21810 COPLEY DRIVE
DIAMOND BAR, CA 91765
PREPARED BY:
SAPPHOS ENVIRONMENTAL, INC.
430 NORTH HALSTEAD STREET
PASADENA, CALIFORNIA 91107
.1ANUARY 22, 2026
1. INTRODUCTION
This Mitigation Monitoring and Reporting Program (MMRP) has been prepared [Julrsuant to Public
Resources Code Section 21081.6, which requires a Lead Agency to adopt a "reporting or
monitoring program for changes to the project or conditions of project approval, adopted in order
to mitigate or avoid significant effects on the environment." In addition, Section 15097(a) of the
California Environmental Quality Act (CEQA) Guidelines requires that a public agency adopt a
program for monitoring or reporting mitigation measures and project revisions, which it has
required to mitigate or avoid significant environmental effects. This MMRP has been prepared in
compliance with the requirements of CEQA, Public Resources Code Section 21081.6, and
Section 15097 of the State CEQA Guidelines.
As stated in State CEQA Guidelines Section 15097(c), "monitoring" refers to the ongoing or
periodic process of the project oversight provided by the "Monitoring Agency." "Reporting" refers
to written compliance review that will be presented to the decision -making body or authorized staff
person. A report can be required at various stages throughout the project implementation or upon
completion of the mitigation measure.
The City of Diamond Bar is the Lead Agency for the Diamond Bar Town Center Specific Plan
Alternative 3 (hereafter, Alternative 3) and, therefore, is responsible for administering and
implementing the MMRP.
Diamond Bar Town Center Specific Plan Mitigation Monitoring and Reporting Program
January 22, 2026 Page 2
2. PROJECT DESCRIPTION
Planning Horizon
The planning horizon is the period of time for which Alternative 3 looks ahead in order to
comprehensively plan for the City's next major phase of growth, change, and development.
Alternative 3 establishes a horizon year of 2040, consistent with the City of Diamond Bar General
Plan 2040 (General Plan 2040).'
Alternative 3: High Density, No Road Diet
Alternative 3 would involve the phased redevelopment of approximately 45 acres of existing
suburban -style retail shopping centers. Currently, the Planning Area has 510,000 square feet of
existing commercial space comprised of retail, dining, and medical office, as well as 97 hotel
rooms. Alternative 3 includes objective design standards that would apply a unified design vision
to all future development to create a "sense of place."
Development Buildout
Alternative 3 would result in up to 2,055 housing units (increase of 705 units); 200 hotel rooms
(increase of 103 rooms); 40,000 square feet of public open space (increase of 40,000 square
feet); and 446,000 square feet of commercial space (decrease of 64,000 square feet), including
retail, dining, and entertainment uses (Table 2-1, Alternative 3 Maximum Buildout). The proposed
increase in density is consistent with the major conclusions of the Urban Land Institute — Los
Angeles (ULI-LA) Technical Assistance Panel (TAP) report, which states that "The TAP's vision
for the Diamond Bar Town Center includes higher residential densities than currently allowed in
the Vision 2040 General Plan." 2 Alternative 3 would also include supporting infrastructure through
the adoption of Alternative 3 and associated entitlements.
To ensure a conservative approach, the analysis assumes maximum buildout of new housing
unitsI new commercial development, and related uses (Table 2-1). Actual buildout is dependent
on market conditions, birth rates, death rates, immigration rates, availability of resources, and
entitlement processes from federal, state, and local regulations. Actual buildout of Alternative 3
would involve the development of new driveways and privately owned accessways between
development within the Planning Area in addition to the development associated with housing,
hotels, and commercial space. New development would be required to conform to the Objective
Design Standards and Guidelines of the Specific Plan. Based on the density of development, the
Diamond Bar Town Center Specific Plan Supplemental Environmental Impact Report (SIR)
assumes that maximum buildout of Alternative 3 would involve construction of three- to six -story -
high buildings within the Planning Area.3
' City of Diamond Bar. 2019. Diamond Bar General Plan 2040. https://www.diamondbarca.gov/961/General-Plan-
2040
2 Urban Land Institute, April 2021, Diamond Bar Town Center Technical Assistance Panel Report.
https://www.diamondbarca.gov/DocumentCenterNiew/8250/Diamond-Bar-Town-Center-Report-April2O2l ?bidld=
(accessed October 29, 2024),
3 City of Diamond Bar. 2026. Diamond Bar Town Center Specific Plan: Final Supplemental Environmental Impact
Report. State Clearinghouse No. 2018051066. Prepared by Sapphos Environmental, Inc.
Diamond Bar Town Center Specific Plan Mitigation Monitoring and Reporting Program
January 22, 2026 Page 3
TABLE 2-1
Alternative 3 Maximum Buildout
General Plan 2040 Existing
Conditions 2023
High Density, No Road Diet
Housing units
0
2,055
Hotel
97 rooms
200 rooms
Retail/commercial
5101000 SF
446,000 SF
Open sace
0 SF
40,000 SF
Road diet
No
No
Number of Diamond Bar Blvd traffic lanes
6 lanes (within Planning Area) &
landscaped median
6 lanes
Travel lane width
11-14.5
feet
11-14.5
feet
Turn pocket width
8.5-15 feet
8,5-15 feet
Bicycle lanes on Diamond Bar Blvd
Yes Class II/on street
Yes Class II/on street
Street parking on Diamond Bar Blvd
Not allowed
Not allowed
Sidewalk width on Diamond Bar Blvd
8-15 feet
8-15 feet
Bicycle lanes on Golden Springs Dr
Yes Class II
Yes Class II
Bicycle lanes on Grand Avenue
No
No
Bicycle lanes on Prospectors Road
No
No
Bicycle lanes on Sunset Crossing Road
No
No
Source: Transportation Study (Appendix F to Supplemental Environmental Impact Report).
City of Diamond Bar, December 2019. Diamond Bar General Plan 2040. https://www.diamondbarca.gov/961/General-Plan-
2040
Note: Class II Bicycle Lanes: on -street bicycle lanes that are not protected from vehicular traffic, demarcated by paint and
signage.
The width of a typical sidewalk for a major arterial street through a commercial zone is 12-15 feet or more.
The General Plan 2040 proposes Class IV and Class III bicycle facilities within the Planning Area.
As indicated in Section 6.5 of the Specific Plan, structures would be up to 45 to 75 feet high
depending on bung type (see Table 2-2, Alternative 3 Maximum Building Heights by Building
Type). Additionally, for height averaging, up to 30 percent of the building footprint area may be
one story (10 feet) taller than the maximum height allowed in a given zone, provided an equal
amount of building footprint area is one story (10 feet) shorter than the maximum allowed height.
Diamond Bar Town Center Specific Plan Mitigation Monitoring and Reporting Program
January 22, 2026 Page 4
TABLE 2-2
Alternative 3 Maximum Building Heights by Building Type
Maximum
Height
BuildinTypes
45
feet
Town House
50
feet
Flex/Loft Building
55
feet
Exposed Garage Building
65
feet
Courtyard Building
Urban Supermarket
Urban Anchor Building
75
feet
Liner Building with Garage
Urban Block Building
Alternative 3 Development Standards
Alternative 3 contains numerous development standards that would avoid and/or reduce
environmental impacts. These design standards are described in detail in the Specific Plan in
Appendix G (Town Center Specific Plan) to the Draft SIR, with a selection presented in Table 2-
3, Alternative 3 Design Standards,
TABLE 2-3
Alternative 3 Design Standards
S ecfic Plan Section
Relevance
3.
Public Realm
Design features in public space that encourage pedestrian activity, and reduce
reliance on cars,
4.
Infrastructure
Upgrades to infrastructure, potentially resulting in a reduction in water and
energy use.
5,
Land Use, Density and
Allowable residential uses and densities to support a variety of housing
Intensity
Standards
opportunities.
6,
Objective Design Standards
Support the development of a "sense of place" throughout the Planning Area by
setting forth building types, massing, landscaping, grading, lighting, parking,
pedestrian and bicycle access, utilities, si na e, architectural standards et al.
The design components or characteristics of future development under the Specific Plan would
comply with these development standards. For example, future development would require trash
receptacles to be covered and properly maintained in order to prevent potentially adverse odors.
In addition to design standards, the Specific Plan identifies constraints, opportunities, and other
guidance to support the City's goal of transforming the Planning Area into the vision described
therein.
Construction Scenario
The Specific Plan is a planning -level document and, as such, there are no known projects,
construction dates, or construction plans at this time. However, the type and size of total
anticipated growth were estimated for the purposes of this environmental analysis, including a
reasonable worst -case annual construction scenario.
Diamond Bar Town Center Specific Plan Mitigation Monitoring and Reporting Program
January 22, 2026 Page 5
Although future development that would occur under Alternative 3 would be subject to market
conditions and various factors, the analyses throughout the Supplemental Environmental Impact
Report (SIR) assume the maximum buildout that could occur with Alternative 3 implementation.
Individual development projects that could occur under Alternative 3 would be subject to the
applicable provisions of CEQA and would require additional survey, design, and engineering work
to support design development and ultimately project construction, operation, and maintenance.
The existing land uses within the Town Center Focus Area that would not be redeveloped would
remain open during the construction of individual projects, with portions of the subject property
closed off as necessary for construction activity. The anticipated development described in the
Specific Plan would be constructed within the Planning Area boundaries.
The exact locations of future projects and construction that would occur under Alternative 3 are
not known at this time, although it is assumed that some of the activities would take place in close
proximity to sensitive receptors, such as homes and schools. The severity of impacts due to
construction (such as air quality or noise) would ultimately depend on project -specific information,
such as the proximity of construction activities to sensitive receptors, the presence of intervening
barriers, the number and types of equipment used, and the duration of the activity. While these
details are not available at this time, it is assumed that future projects would comply with all
applicable federal, state, regional, and local regulations and standards.
Construction Schedule
While phasing of individual projects cannot be determined, construction impacts were analyzed
based on the assumption that construction could begin as early as summer 2025, and continue
through 2041, consistent with the planning horizon and assumptions of the General Plan 2040.
Construction is forecast based on the expectation that a maximum of 12.5 percent of the total
new development under Alternative 3 could be developed in any year (i.e., an even annual rate
of development over 15-16 years would result in 6.25 percent of Alternative 3 being built per year;
therefore, conservatively, this analysis assumes a maximum of twice that much development per
year or 12.5 percent of Alternative 3's maximum buildout).
Construction Activities
Construction would require the use of heavy equipment during the demolition, grading,
excavationI and other construction activities with the Planning Area. During each stage of
development for any given construction project, a different mix of equipment would be used. As
such, construction activity would fluctuate depending on the particular type, number, and duration
of use of the various pieces of equipment.
Construction activities would include demolition, site preparation, excavation, grading, building
construction, and paving. The analysis assumes that earthmoving cut and fill of soil would be
minimized onsite to minimize soil import or export by haul trucks. Heavy-duty equipment, vendor
supply trucks, and concrete trucks would be used during construction of foundations and
buildings. Landscaping and architectural coating would occur during the finishing activities.
Diamond Bar Town Center Specific Plan Mitigation Monitoring and Reporting Program
January 22, 2026 Page 6
Construction Equipment
The following types of construction equipment could potentially be used in the construction of
individual projects under Alternative 3:
• Dump trucks
• Graders or dozers for earthwork
• Concrete/industrial saws
• Crew vehicles
• Rubber tired dozers
• Tractors/loaders/backhoe
• Delivery Trucks
• Scrapers
• Excavators
• Cranes
• Forklifts
• Generator sets
• Welders
• Pavers
• Paving equipment
• Rollers
• Air compressors
• Pile drivers
This list of typical construction equipment was used to evaluate Alternative 3's potential
construction impacts.
Construction Requirements
Site preparation and construction for individual projects would be undertaken in accordance with
all federal, state, and local applicable building codes. Development within the City, including the
Planning Area, is required to comply with Chapter 22.28, Noise Control, of the Diamond Bar City
Code. Daily construction activities would be undertaken Monday through Saturday, between 7:00
a.m. and 7:00 p.m. No work shall be conducted on Sundays or any recognized federal, state, or
local holidays.'
The construction contractor shall ensure that all construction and grading equipment is properly
maintained. All stockpiles shall be covered at all times when not in use. Best management
practices (BMPs) shall be utilized through the duration of the construction per the Storm Water
Pollution Prevention Plan (SWPPP).
In accordance with Section 7050.5 of the California Health and Safety Code, if human remains
are encountered during excavation activities, the County Coroner shall be notified within 24 hours
of the discovery. No further excavation or disturbance of the site or any nearby areas reasonably
suspected to overlie adjacent remains within 100 feet shall occur until the County Coroner has
determined the appropriate treatment and disposition of the human remains.
a City of Diamond Bar, N.d. Chapter 22.28 —Noise Control. Diamond Bar City Code.
https://library.municode.com/ca/diamond_bar/codes/code_of ordinances?nodeld=CICO_TIT22DEC0_ARTIIISIPLGE
DEST_CH22.28NOCO
Diamond Bar Town Center Specific Plan Mitigation Monitoring and Reporting Program
January 22, 2026 Page 7
The SIR was prepared to address the potential environmental impacts %J Alternative 3. The
evaluation of the Alternative 3's impacts in the SIR takes into consideration the mitigation
measures (MMs) that were incorporated into the SIR to avoid or reduce potentially significant
environmental impacts. This MMRP is designed to monitor implementation of the MMs identified
for Alternative 3 (Table 3-1, Mitigation Monitoring and Reporting Program).
Diamond Bar Town Center Specific Plan Mitigation Monitoring and Reporting Program
January 22, 2026 Page 8
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Exhibit 2
DIAMOND BAR TOWN CENTER SPECIFIC PLAN
FINDINGS OF FACT
STATEMENT OF OVERRIDING CONSIDERATIONS
STATE CLEARINGHOUSE NO.2018051066
PREPARED FOR:
CITY OF DIAMOND BAR
21810 COPLEY DRIVE
DIAMOND BAR, CA 91765
SAPPHOS ENVIRONMENTAL, INC.
430 NORTH HALSTEAD STREET
PASADENA, CALIFORNIA 91107
FEBRUARY 25, 2026
TABLE OF CONTENTS
SECTION
PAGE
Introduction and Background........................................................................................ I-1
1.1 Certification....0598.5.4.....4...9....994..0...00...4.....000..0...0.2.00.0.02.0.0..0..0.......00..0.......009.I-1
1.2 Project Location. a N 0 a s a a 0 0 a 0 & M s a a M M 0 a 0 N 0 2 0 M a 0 0 0 a a a a a 0 0 9 s 0 s 1 0 0 V 0 V A A M M a W 9 M 4 x M 4 0 0 A 4 0 4 0 4 4 4 P 0 0 0 A 0 M W 0 N W * % a V n 9 a I-2
1.3 Project Goals and Objectives........................................................................ I-2
1.4 Staff -Recommended Project: Alternative 3 (High Density, No Road Diet) ....... 1-3
1.5 CEQA Review Process.................................................................................. I-6
II Potential Environmental Effects That Are Less than Significant....................................II-1
11.1 Aesthetics.................................................................................................... I I-1
11.2 Air Quality. . a a 0 0 a I a 0 a a 0 a * a a a a * a 0 1 a * a a a I a a a a I a a a 0 a 0 a a 0 0 a a a 0 M 0 a 0 s 0 0 A a 0 a M 2 0 M M a 0 B a x A B a 0 M M a M 0 4 a S q 0 a * q & V a 4 4 0 0 M * 0 A 11-2
11.3 Greenhouse Gas Emissions......................................................................... 11-5
11.4 Hydrology and Water Quality........................................................................ II-5
11.5 Noise........................................................................................................... II-6
11.6 Public Services............................................................................................ II-7
11.7 Recreation................................................................................................. II-10
11.8 Utilities and Service Systems..................................................................... II-11
III Potential Environmental Effects That Can Be Mitigated to a Level of Insignificance ....III-1
IV Significant Unavoidable Adverse Impacts That Cannot Be Mitigated to Below the
Levelof Significance................................................................................................... IV-1
IV.1 Air Quality................................................................................................... IV-1
IV.2 Transportation.............................................................................................IV-6
V Findings Regarding Recommended Project and Alternatives Not Recommended for
Adoption...................................................................................................................... V-1
V.1 Range of Reasonable Alternatives................................................................ V-2
V.2 Comparative Analysis of Alternatives............................................................ V-3
V.3 Environmentally Superior Alternative.......................................................... V-14
VI Findings Regarding Mitigation Monitoring and Reporting Program ............................ VI-1
Al
Finding Regarding Location and Custodian of Documents ........................................ VII-1
VIII Finding Regarding Independent Judgment. a 0 0 a 0 0 0 a * a a 0 0 M a 0 M M M A M 0 a A A a a a a a 4 a 4 4 & 1 0 1 a * d 0 0 * N 0 4 0 * * 4 0 6 n 9 V R v 0 * a a VIII-1
IX State CEQA Guidelines Sections 15091, 15092, and 15093 Findings ....................... IX-1
IX.1 State CEQA Guidelines Section 15091 Findings .......................................... IX-1
IX.3 State CEQA Guidelines Section 15093 Findings .......................................... IX-3
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page i
X CEQA Guidelines Section 15093 Findings: Statement of Overriding Considerations... X-1
XI
References................................................................................................................. XI-1
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page ii
I INTRODUCTION AND BACKGROUND
101 Certification
Findings of Fact and Statement of Overriding Considerations Regarding the Diamond Bar
Town Center Specific Plan Final Supplemental Environmental Impact Report (State
Clearinghouse Number No. 2018051066)
As required pursuant to Section 15090 of the State of California Environmental Quality Act
(CEQA) Guidelines, the City of Diamond Bar (City) certifies that the Supplemental Environmental
Impact Report (SIR) for the Diamond Bar Town Center Specific Plan (State Clearinghouse No.
2018051066) has been completed in compliance with CEQA. The Diamond Bar Town Center
Specific Plan SIR supplements both the certified Diamond Bar Comprehensive General Plan
Update and Climate Action Plan Draft Environmental Impact Report (certified in 2019) (Certified
General Plan EIR) that was prepared for the Diamond Bar General Plan 2040 (adopted in 2019)
(General Plan 2040) as refined by the Addendum EIR prepared for the General Plan 2040
(certified in 2022) for the 2021-2029 Housing Element Update, and Land Use and Economic
Development Updates (adopted in 2022).112;3 These are available for review at the project website,
A Downtown for Diamond Bar:
https://www.downtown4db.com/environmental-review.
The Final SIR was presented to the City Planning Commission and City Council. The Planning
Commission provided its recommendations to the City Council for review and consideration. The
City is the Lead Agency pursuant to CEQA, and the City Council is the decision -making body who
acts on behalf of the City. The City Council has reviewed and considered the information
contained in the Final SIR prior to approving the project.
• The Final SIR is comprised of Volume I: Draft SIR, dated August 2025; Volume II:
Technical Appendices to the Draft SIR, dated August 2025; and Volume III: Final SIR,
dated January 2026.
• This document is available for review by the public starting January 2026 at:
https://www.downtown4db,com/environmental-review
The Final SIR reflects the City Council 's independent judgment and analysis.
As required by Section 15092 of the State CEQA Guidelines, the City Council has:
• Eliminated or substantially lessened all significant effects on the environment where
feasible as demonstrated in the Section 15091 Findings.
• Determined that any remaining significant effect on the environment found to be
unavoidable pursuant to the Section 15091 Findings are acceptable due to overriding
concerns as described in Section 15093.
City of Diamond Bar. 2019. Diamond Bar Comprehensive General Plan Update and Climate Action Plan Draft
Environmental Impact Report. https://ceqanet.opr.ca.gov/2018051066/2
2 City of Diamond Bar. 2019. Diamond Bar General Plan 2040. https://www,diamondbarca.gov/961/General-Plan-
2040
3 City of Diamond Bar. 2022. Diamond Bar General Plan 2040 Housing Element Update 2021-2029,
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page 1-1
As required by Section 15093 of the State CEQA Guidelines, the City Council's approval of the
project, which will result in the occurrence of significant impacts that are identified in the Final SIR
that are not avoided or substantially lessened to a less than significant level, include a written
statement of overriding considerations stating the specific reasons to support its actions based
on the Final SIR and other information in the administrative record for the Final SIR.
1.2 Project Location
The Planning Area is approximately 45 acres, less than 0.5 percent of the land area within the
City limits, bounded on the north by the Pomona Freeway (State Route [SR] 60), on the east by
a neighborhood of single-family homes, on the south by Lorbeer Middle School and Mount
Calvary Lutheran Church and School, and on the west by the Fall Creek private condominium
community. The Planning Area is composed of 35 individual parcels with 23 unique property
owners within a suburban -style commercial district (see Section 2.1, Regional Location and
Project Boundaries, in the Draft SIR). The Planning Area is centered around Diamond Bar
Boulevard, a six -lane thoroughfare with painted bike lanes, that bisects the Town Center and
extends over 1,800 feet. It is bounded on the south by Golden Springs Drive for approximately
1,600 feet and on the north by the SR-60 Freeway. Access to the Town Center is provided by
both SR-60 and SR-57. Traveling on SR-60, access to the Town Center can be attained by
Diamond Bar Boulevard (Exit 26).
1.3 Project Goals and Objectives
Section 1.5, Plan Goals, in the Specific Plan lists eight goals. These goals are listed below as the
eight objectives of the Diamond Bar Town Center Specific Plan for purposes of this SIR:
1. Implement the community vision, goals, and policies of the General Plan, which
established the Town Center Mixed Use land use designation to "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."
2. Make the Town Center a complete neighborhood with a sense of place, that takes
advantage of its location, to provide residents and visitors a unique experience.
3. Ensure that the physical design and programming of the Town Center supports health,
wellbeing, and environmental sustainability, the latter so as to make progress toward
meeting the greenhouse gas reduction targets of the Diamond Bar Climate Action Plan by
supporting compact, infill, mixed -use development.
4. Allow for cardite / car -optional living allowing those who choose not to use their car on a
daily basis or who choose not to own a car at all to be easily accommodated thus furthering
progress to the City's climate action goals.
5. Provide great public spaces, and small parks with regenerative landscapes to support the
goal of environmental sustainability.
6. Include a mix of uses and urban housing types at a range of affordability levels, so as to
implement the 6th Cycle Housing Element (Chapter 9 of the General Plan) and to fulfill
Diamond Bar's commitment to provide affordable housing opportunities by rezoning the
Town Center Specific Plan project area to facilitate the development of a portion of
Diamond Bar's Regional Housing Needs Assessment (RHNA) allocation, including the
production of housing that will be affordable to lower -income households.
7. Provide flexibility for the future — particularly for retail and commercial space — so as to
adapt to changes in lifestyle and market conditions that are likely to occur throughout the
lifespan of the plan.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page I-2
8. Facilitate the development of the Town Center in phases or increments so as to recognize
the multiple owners in the Plan Area and the expectation that these owners will likely have
different time frames for redevelopment.
1.4 Staff Recommended Project: Alternative 3: High Density, No Road
Diet
Alternative 3, the High Density, No Road Diet Alternative, is intended to implement the General
Plan 2040 by supporting its vision and development policies that guide the physical growth of the
Planning Area. The Specific Plan details development standards, infrastructure requirements, and
implementation measures for the Town Center, Alternative 3 establishes a horizon year of 2040,
consistent with the General Plan 2040. The Specific Plan proposes the development of up to
2,055 housing units, which would result in a maximum residential density of approximately 46
dwelling units per acre (du/ac) in the Planning Area, as well 200 hotel rooms, 40,000 square feet
(sf) of public open space, 446,000 sf of redeveloped commercial space, and supporting
infrastructure (Table 1.4-1, Comparison of Certified General Plan EIR to Recommended Project:
Alternative 3, High Density, No Road Diet). The six lanes of Diamond Bar Boulevard are retained
within the Planning Area, with 114eet wide lane widths, and 10-feet-wide turn pockets (Table 1.4-
1). Alternative 3 does not accommodate parking on Diamond Bar Boulevard (Table 1.4-1). The
existing &foot -wide sidewalks adjacent to Diamond Bar Boulevard are retained. Alternative 3
includes Class IV bicycle lanes on Golden Springs Drive, Grand Avenue, and Prospectors Road
and a Class III bicycle lane on Sunset Crossing Road (Table 1.4-1). Alternative 3 achieves the
basic objectives of the Specific Plan, Alternative 3 is compatible with the City's adopted "Complete
Streets" Project. Alternative 3 retains all three existing traffic lanes in each direction on Diamond
Bar Boulevard.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page I-3
TABLE 1.4-1
COMPARISON OF CERTIFIED GENERAL PLAN EIR TO RECOMMENDED PROJECT:
ALTERNATIVE 3, HIGH DENSITY, NO ROAD DIET
No -Project
General Plan 2040
Alternative
Existing
(Housing Element
Conditions 2023
Update)
Alternative 3
Proposed Change
Housing units
0
11350
21055
+2,055 units
Hotel
97 rooms
97 rooms
200 rooms
+103 rooms
Retail/commercial
510,000 sf
5101000 SF
446,000 sf
—64,000 sf
Open sace
0 sf
0 SF
40,000 sf
+40,000 sf
Road diet
No
No
No
No change
Number of Diamond
6 lanes (within
6 lanes
6 lanes
No change
Bar Blvd traffic
Planning Area) &
lanes
landscaped median
Travel lane width'
11-14.5
feet
11
feet
11
feet
0-3.5 feet
Turn pocket width'
8.5-15 feet
10 feet
10 feet
—5 feet — +1.5 feet
Bicycle lanes on
Yes (Class II/on
Yes (Class IV)
Yes
No change
Diamond Bar Blvd
street)'
Street parking on
Not allowed
Not allowed
Not allowed
No change
Diamond Bar Blvd
Sidewalk width on
8-15 feet2
8-15 feet
8-15 feet
No change
Diamond Bar Blvd
Bicycle lanes on
Yes (Class II)
Yes (Class IV)
Yes (Class (I)21314
On -street bike lanes
Golden Springs Dr
to Protected bike
Ianes12A
Bicycle lanes on
No
Yes (Class IV)
Yes (Class IV)2,3,4
No bike lanes to
Grand Avenue
Protected bike
lanes12,4
Bicycle lanes on
No
Yes (Class IV)
Yes (Class IV)1213,4
No bike lanes to
Prospectors Road
Protected bike
lanes12,4
Bicycle lanes on
No
Yes (Class III)
Yes (Class III),2,314
No bike lanes to
Sunset Crossing
Shared bike lanes12,4
Road
Source. Transportation Study (Appendix F to SIR).
City of Diamond Bar. December 2019. Diamond Bar General Plan 2040. https://www.diamondbarca.gov/961/General-Plan-2040
Note. sf = square feet.
1 Turn Lane width and turn pocket width are based on the width with the Complete Streets Project in place for the approved
General Plan 2024 and proposed Alternative 3.
2 Alternative 3 is able to accommodate the Bicycle Lane improvements contemplated by the Complete Streets Project: lass II
Bicycle Lanes: on -street bicycle lanes that are not protected from vehicular traffic, demarcated by paint and signage. Class III
Bicycle Lanes: bicycle routes that are shared with vehicles, typically on low -volume, low -speed streets. Class IV Bicycle Lanes:
protected bicycle lanes/bikeways that are physically separated from vehicle traffic and are exclusively for bicycle use.
3 Alternative 3 is able to accommodate the Bicycle Lane improvements contemplated by the Complete Streets Project: The width
of a typical sidewalk for a major arterial street through a commercial zone is 12-15 feet or more,
4 Alternative 3 is able to accommodate the Bicycle Lane improvements contemplated by the Complete Streets Project: The
General Plan proposes Class IV and Class III bicycle facilities within the Planning Area.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page I-4
Development Buildout
When compared to the No -Project Alternative (adopted General Plan 2040, as most recently
updated by the 2019 Housing Element Update) Alternative 3 includes up to 2,055 housing units
(increase of 755 units); 200 hotel rooms (increase of 103 rooms); 40,000 square feet of public
open space (increase of 40,000 square feet); and 446,000 square feet of commercial space
(decrease of 64,000 square feet), including retail, dining, and entertainment uses (see SIR
Section 4.4, Description of Alternatives, and Table 4.4-1, Comparison of Key Characteristics for
Refined Project and Alternatives). The proposed increase in density is consistent with the major
conclusions of the Urban Land Institute — Los Angeles (ULkLA) Technical Assistance Panel (Tap)
Report,4 which states that "The TAP's vision for the Diamond Bar Town Center includes higher
residential densities than currently allowed in the Vision 2040 General Plan."5 Alternative 3 also
includes supporting infrastructure through the adoption of Alternative 3 and associated
entitlements.
To ensure a conservative approach, the analysis in the SIR assumed maximum Buildout of new
housing units, new commercial development, and related uses. Actual buildout is dependent on
market conditions, birth rates, death rates, immigration rates, availability of resources, and
entitlement processes under federal, state, and local regulations. Actual buildout of Alternative 3
would involve the development of new driveways and privately owned accessways between
development within the Planning Area in addition to the development associated with housing,
hotels, and commercial space, in order to present a worst -case scenario throughout the analysis
in the SIR. Based on the density of development, the SIR assumes that maximum buildout of
Alternative 3 would involve construction of three- to six -story -high buildings within the Planning
Area. New development would be required to conform to the Objective Design Standards and
Guidelines of the Specific Plan. Alternative 3 includes objective design standards that would apply
a unified design vision to all future development to create a "sense of place."
General Plan Amendment
A General Plan Amendment would be required to increase the maximum residential density
allowed within the Planning Area to allow Alternative 3 proposed density.
The "Town Center Mixed Use" land use designation in the Land Use and Economic Development
Chapter of the General Plan 2040 establishes a maximum floor area ratio (FAR) of 1.5 and a
residential density of 20.0 to 30.0 du/ac.6
Alternative 3 proposes the development of up to 2,055 housing units, which would result in a
maximum residential density of approximately 45.7 du/ac in the Planning Area and assumes that
all housing developments would include either 5 percent low-income or 15 percent moderate-
4 City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
April2021?bidld= . Accessed January 13, 2026.
5 Urban Land Institute -Los Angeles, April 2021. Technical Assistance Panel Report: Diamond Bar Town Center.
https://www.diamondbarca.gov/DocumentCenterNiew/8250/Diamond-Bar-Town-Center-Report-Apri]2021 ?bidld=
(accessed October 29, 2024).
6 City of Diamond Bar. August 2022. Diamond Bar General Plan 2040: Land Use and Economic Development
Element 2021-2029. https://www.diamondbarca.gov/DocumentCenter/View/8443/2021-2029-Housing-Element-
Update?bidld=
Diamond
Bar
Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page I-5
income units. Alternative 3 would involve amendments to the General Plan 2040 to update the
maximum residential density for the Town Center Mixed Use land use designation.
Zoning Amendment
An amendment to the City Zoning Map would be required to re -zone all parcels within the Planning
Area to "Specific Plan." Alternative 3 would specify the permitted uses, maximum residential
density, and FAR within the Planning Area.
All parcels in the Planning Area are zoned by the City as Regional Commercial (C-3), Community
Commercial (C-2), and Neighborhood Commercial (C-1). Title 22, Development Code, of the
City's Code of Ordinances states that the allowable FAR for nonresidential development in these
zones shall be from 0.25 to 1.001' which is less than the Alternative 3 FAR. Consistent with the
Housing Element 2021-2019, Alternative 3 would involve amendments to the City Zoning Map to
rezone all parcels in the Planning Area to "Specific Plan" to allow the proposed density and FAR
of Alternative 3.
1.5 CEQA Review Process
This section describes the environmental review process undertaken for this SIR pursuant to
CEQA.
Notice of Preparation and Scoping
The Notice of Preparation (NOP) was issued on June 5, 2023, and the public scoping period
was from June 5, 20231 to July 5, 2023. A Notice of Completion (NOC) of an initial study was
filed with the State Office of Planning and Research, and the NOP was filed with the Los Angeles
County Clerk -Recorder and distributed by issuance in the San Gabriel Tribune on June 5, 2023,
and notices mailed to 905 interested stakeholders, property owners, and business owners within
a 1,000400t radius of the Planning Area. A scoping meeting was held on June 8, 2023, at the
Windmill Room, Diamond Bar City Hall, 21810 Copley Drive, Diamond Bar, California 91765,
The NOP and Initial Study were available for review during the scoping period at the offices of
the City of Diamond Bar Planning Division, located at 21810 Copley Drive, Diamond Bar,
California 91765 and on the Planning Division website:
https://www.diamondbarca.gov/1065/Town-Center-Specific-Plan
The NOP and related comment letters received are included as Appendices A and C,
respectively, of the SIR.
Tribal Consultation
Pursuant to State law (Assembly Bill [AB] 52 and Senate Bill [SB] 18), the City contacted and
sent letters for consultation on June 7, 2022, to nine Native American Groups and received two
replies during the 90-day consultation request period required under SB 18:
� City of Diamond Bar. N.d. Code of Ordinances, Title 22 —Development Code, Chapter 22.10 —
Commercial/Industrial Zoning Districts.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page I-6
1. On June 10, 2022, Andrew Salas of the Gabrieleno Band of Mission Indians — Kizh
Nation stated that they agree with the Diamond Bar Town Center Specific Plan but would
like to request further consultation if ground disturbance is to occur for all future projects
at this location.
2. On July 7, 2022, Christina Conley of the Gabrielino Tongva Indians of California
responded stating that they have no comment on the Diamond Bar Town Center Specific
Plan.
In addition, the City contacted and sent letters for AB 52 consultation on July 9, 2025, to three
Native American Groups and received two replies during the 30-day required consultation request
period:
1. On July 9, 2025, Joseph Ontiveros of the Soboba Band of Luiseno Indians requested that
consultation be deferred to Anthony Morales of the San Gabriel Band of Mission Indians.
2. On July 10, 2025, Brandy Salas of the Gabrieleno Band of Mission Indians - Kizh Nation
stated that they have no concerns at this time and requested notification prior to any
ground -disturbing activities.
3. As of August 9, 2025, the City did not receive any response from Anthony Morales of the
Gabrieleno/Tongva San Gabriel Band of Mission Indians. The City made an unsuccessful
effort to contact Mr. Morales via telephone on July 9, 2025, and two additional contact
efforts were made via email on July 9 and 16, 2025.
Although no Native American (Tribal) consultation was requested for the Diamond Bar Town
Center Specific Plan under SB 18 and AB 52, consistent with the Certified General Plan EIR,
City staff shall facilitate project -specific consultation prior to ground disturbance occurring for
future projects within the Planning Area (Certified General Plan EIR Mitigation Measure 3.4-2).
No Tribal cultural resources have been previously recorded intersecting the Planning Area or
within a quarter -mile radius, and background research does not indicate the presence of Tribal
cultural resources within the Planning Area. Any Tribal cultural resources found on the project
site during construction would be protected by adherence to Resource Conservation Measures
RC-P-49 and RC-P-50. In accordance with Section 7050.5 of the California Health and Safety
Code, if human remains are encountered during excavation activities, the County Coroner shall
be notified within 24 hours of the discovery. Furthermore, the Diamond Bar Town Center
Specific Plan would implement Certified General Plan EIR Resource Conservation Measures
RC-G-15, RC-P-49, and RC-P-50, as well as comply with regulatory requirements relating to
the unanticipated discovery of Tribal cultural resources.
Draft SIR Review
The Draft SIR was distributed for review to the public and interested and affected agencies for
a period of 46 days from August 25, 2025, to October 10, 2025. An NOC of a Draft SIR was
filed with the State Office of Planning and Research, and the Notice of Availability (NOA) was
filed with the Los Angeles County Clerk -Recorder and distributed by issuance in the San Gabriel
Valley Tribune on August 25 and September 8, 2025, and notices mailed to 910 interested
stakeholders, property owners, and business owners within a 1,000400t radius of the Planning
Area.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page I-7
The NOA, Draft SIR, and all related technical studies were available for review during the public
review period at the offices of the City of Diamond Bar Planning Division, located at 21810
Copley Drive, Diamond Bar, California 91765 and on the Planning Division website:
https:www.diamondbarca.gov/1065/Town-Center-Specific-Plan
Final SIR and Certification
A total of 28 comment letters and emails were received during the 46-day public review period
between August 25, 2025, and October 10, 2025. The City, as Lead Agency, considered all
comments and has provided written responses to comments received on the Draft SIR per
CEQA Guidelines Section 15088. All comments received during the public review period and
responses to those comments are included in the Final SIR.
Relevant Plans and Environmental Studies
Pursuant to CEQA Guidelines Section 15150, an EIR may incorporate by reference all or
portions of another document which is a matter of public record or is generally available to the
public. Where all or part of another document is incorporated by reference, the incorporated
language shall be considered to be set forth in full as part of the text of the SIR. Documents
incorporated by reference must be briefly summarized in the SIR and made available to the
public for inspection at a public place or a public building. The following reports are hereby
incorporated by reference and are available for review at the City of Diamond Bar Planning
Division:
• City of Diamond Bar Existing Conditions Report, Volumes I, II, and III (March 2017)
• City of Diamond Bar Adopted General Plan, including Certified Housing Element
(December 2019—August 2022)
• City of Diamond Bar Adopted Climate Action Plan (December 2019)
• City of Diamond Bar 6t" Cycle Housing Element (Adopted by the City Council August
2022, certified by HCD October 2022)
• City of Diamond Bar Addendum No. 1 to General Plan Update EIR for Housing Element
(August 2022)
Diamond
Bar
Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page I-8
II POTENTIAL ENVIRONMENTAL EFFECTS THAT
ARE LESS THAN SIGNIFICANT
The analysis undertaken in support of the SIR for the Specific Plan determined that Alternative 3
(High Density, No Road Diet) will result in less than significant impacts, taking into consideration
clarifications and revisions to the Draft SIR, in relation to the following environmental resource
categories articulated in Appendix G of the State CEQA Guidelines:
11.1 AESTHETICS
Impact 3.1.1 Would the project create a new source of substantial light or glare which
would adversely affect daytime or nighttime views in the area?
Impact:
Less than Significant.
Finding:
The analysis in the SIR (Section 4.6.1, Aesthetics) determined that Alternative 3 will result in less
than significant impacts to aesthetics in relation to creating a new source of substantial light or
glare which could adversely affect daytime or nighttime views in the area. No mitigation measures
are required.
Rationale:
General Plan 2040 Policy LU-P-8 ensures that new residential development within the Planning
Area will be compatible with the prevailing character of the surrounding neighborhood in terms
of building scale, density, massing, and design, where the General Plan 2040 designates higher
densities and provides adequate transitions to existing development. Conformance with
provisions in the Diamond Bar City Code that limit light and glare for new non-residential and
residential development (Section 22.16.050. — Exterior lighting; Section 21.30.140. — Street
lighting; and Section 22.30.070. — Development standards for off-street parking) would be
required. Operation and maintenance of Alternative 3 would be implemented in accordance with
City's development code and in conformance with the development standards related to light
shielding for new or modified lighting sources, street lighting installation, and off-street parking
restrictions to reduce sources of light and glare to the extent feasible.
Furthermore, the General Plan 2040 requires that efficient materials and lighting to be
considered based on comfort, safety, visibility, cost, convenience, and environmental impact
during the redevelopment of the mixed -use Town Center.' In addition, the development of
Alternative 3 would be subject to conceptual design and plan check reviews in relation to light
and glare, as well as all design components would be required to comply with City Code section
22.16.050, Exterior Lighting.
' City of Diamond Bar. 2019. Diamond Bar General Plan 2040: Community Character & Placemaking.
https://www.diamondbarca.gov/DocumentCenterNiew/7090/3-Community-Characterr?bidld=
Diamond
Bar
Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page II-1
11.2 AIR QUALITY
Impact 3.2.1 Would the project conflict with or obstruct implementation of the applicable
air quality plan?
Impact:
Less than Significant for Construction and Operation.
Finding:
The analysis in the SIR (Section 4.6.2, Air Quality) determined that Alternative 3 will result in less
than significant impacts to air quality in relation to conflict with or obstruction of implementation of
the applicable air quality plan. No mitigation measures are required.
Rationale:
As discussed in the SIR, Alternative 3 would result in the same level of air quality emissions as
the refined project with respect to both its construction and operation. Accordingly, the SIR
findings for Impact 3.2.1 apply to Alternative 3, meaning Alternative 3 would not conflict with the
2022 AQMP, SCAG's forecasts, and the General Plan. Alternative 3 aligns with the General Plan,
which aims for a diverse and efficiently -operated local and regional ground transportation system
that reduces per capita VMT,2 and with SCAG's Connect SoCal strategies that focus on balancing
the conservation of open space with new development, improving mobility options, and creating
new economic growth in the region .3 The proposed mixed -use development would serve as a
center of activity for residents, provide housing, retail opportunities, and spaces for community
gatherings; and endeavors to influence long-term health by promoting compact development
patterns and transportation demand management measures to reduce VMT. Accordingly,
Alternative 3 would result in less than significant impacts and would not conflict with or obstruct
the implementation of an applicable air quality plan.
Impact 3.2.2 Would the project result in a cumulatively considerable net increase of any
criteria pollutant for which the project region is non -attainment under an
applicable federal or state ambient air quality standard?
Impact:
Less than Significant for Construction.
Finding:
The analysis in the SIR determined that Alternative 3 would result in less than significant impacts
to air quality for construction in relation to a cumulatively considerable net increase of any criteria
pollutant for which the project region is non -attainment under an applicable federal or state
ambient air quality standard.
2 City of Diamond Bar. 2019. Diamond Bar General Plan 2040.Chapter 5 —Resource Conservation.
https://www.diamondbarca.gov/DocumentCenterNiew/7092/5-Resource-Conservationr?bidld=
3 Southern California Association of Governments. September 2020, Connect SoCal.
https: //scag. ca.gov/sites/m ai n/fi les/fi le -attach ments/0903fcon nectsocal-pl an_0. pdf? 1606001176
Diamond
Bar
Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page II-2
Rationale:
The Certified General Plan EIR found that the 2022 Housing and Land Use Element Updates
would exceed South Coast Air Quality Management District (SCAQMD) significance thresholds
for volatile organic compounds (VOCs) and nitrous oxide (NOX) and that construction and
operational impacts would be significant and unavoidable.
Alternative 3 would reduce the construction footprint by dedicating 40,000 square feet (sf) to open
space. As with the Certified General Plan EIR, Diamond Bar Boulevard would not be altered for
the road diet. As a result, Alternative 3 would likely not align as well with Connect SoCal,
specifically the goals and policies pertaining to vehicle miles traveled (VMT) reduction in the
region.
As with the Certified General Plan EIR, Alternative 3 maintains existing longer pedestrian crossing
distances and less space on the existing public right-of-way for alternative uses such as wider
sidewalks, bus turnouts, and additional landscaping. However, Alternative 3 accommodates
Class IV bicycle lanes at Diamond Bar Boulevard, Golden Springs Drive, Grand Avenue, and
Prospectors Road and a Class III bicycle lane on Sunset Crossing Road.
Alternative 3 includes the same land use planning scenario evaluated in Section 3.2, Air Quality,
of the SIR, differing only in the exclusion of the road diet. As such, the findings in Section 3.2
would be comparable to the analysis to the Alternative 3 findings.
As shown in Table 4.6-1, Alternative 3: Overall Estimated Daily Construction Emissions vy Year
(Unmitigated), of the SIR, the Maximum Daily Construction Emissions between 2025 and 2041
would be below the SCAQMD Significance Criteria for all evaluated pollutants. In addition, as
shown in Tables 4.&1 and 4.&2, Alternative 3: Overall Estimated Daily Construction Emissions
by Year (Mitigated), of the SIR, the Maximum Daily Construction Emissions for Alternative 3 are
lower than those calculated for the land use planning scenario as evaluated in the Certified
General Plan EIR for all evaluated Criteria Pollutants. Thus, the construction of Alternative 3
would result in less than significant impacts with respect to a cumulatively considerable net
increase of any criteria pollutant for which the project region is non -attainment under an applicable
federal or state ambient air quality standard.
Impact 3.2.3 Would the project expose sensitive receptors to substantial pollutant
concentrations?
Impact:
Less than Significant for Construction.
Finding:
The analysis in the SIR determined that Alternative 3 would result in less than significant impacts
to air quality in relation to exposing sensitive receptors to substantial pollutant concentrations for
construction.
Diamond
Bar
Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page II-3
Rationale:
The Certified General Plan EIR found that the 2022 Housing and Land Use Updates would expose
sensitive receptors to substantial pollutant concentrations and that construction and operational
impacts from NOx, CO, PM2.5, and PM,owould be significant and unavoidable.
Alternative 3 would reduce the construction footprint by dedicating 40,000 sf to open space. As
with the Certified General Plan EIR, Diamond Bar Boulevard would not be altered for the road
diet. As a result, Alternative 3 would likely not align as well with Connect SoCal, specifically the
goals and policies pertaining to VMT reduction in the region.
As with the Certified General Plan EIR, Alternative 3 maintains the existing longer pedestrian
crossing distances and less space on the existing public right-of-way for alternative uses such as
wider sidewalks, bus turnouts, and additional landscaping. However, Alternative 3,
accommodates Class IV bicycle lanes at Diamond Bar Boulevard, Golden Springs Drive, Grand
Avenue, and Prospectors Road and a Class III bicycle lane on Sunset Crossing Road.
Alternative 3 includes the same land use development scenario evaluated in Section 3.2, Air
Quality, of the SIR, for the refined project. Alternative 3 and the "refined project" differ only in that
Alternative 3 does not include the road diet provided as an element of the refined project. As such,
the construction scenario for Alternative 3 differs only in that the lane configuration, median, and
sidewalks for Diamond Bar Boulevard within the Planning Area would remain in their baseline
condition (see SIR Table 4.&1, Alternative 3: Overall Estimated Daily Construction Emissions by
Year [Unmitigated], and Table 4.&2, Alternative 3: Overall Estimated Daily Construction
Emissions by Year [Mitigated]). As such, the findings in Section 3.2 would be comparable to the
Alternative 3 findings for construction.
The maximum daily construction emissions between 2025 and 2041 would be below the
SCAQMD significance thresholds for all evaluated criteria pollutants (SIR Table 4.6 WEE 1). In addition,
the maximum daily construction emissions for Alternative 3 are reduced when compared to those
calculated for the land use planning scenario evaluated in the Certified General Plan EIR for all
evaluated criteria pollutants (SIR Tables 4.&1 and 4.&2). The reduction in emission of criteria
pollutants results from the changes to the land use planning scenario for Alternative 3 when
compared to that approved in the General Plan 2040 EIR.
As a result, Alternative 3 would reduce the impacts of criteria pollutants during construction for
sensitive receptors, particularly those that live within one-half mile of the Planning Area, or those
that would travel via bicycle or bus through the Planning Area.
Impac3.2.4 Would the project result in other emissi
tons (such as those leading to odors)
adversely affecting a substantial number of people?
Impact:
Less than Significant for Construction and Operation.
Finding:
The analysis in the SIR (Section 4.6.2, Air Quality) determined that Alternative 3 will result in less
than significant impacts to air quality in relation to resulting in other emissions (such as odors)
adversely affecting a substantial number of people. No mitigation measures are required.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page II-4
Rationale:
Alternative 3 does not propose substantial change cm use type or function associated with
potential odor impacts during operation as specified by the California Air Resources Board
(CARB) Air Quality Handbook. During construction, Alternative 3 would potentially result in
temporary and localized odor releases throughout the Planning Area, such as diesel exhaust and
volatile organic compounds. Compliance with CARB and SCAQMD regulations would reduce
diesel fuel combustion odors during the construction. Alternative 3 would result in less than
significant impacts related to other emissions (such as odors) adversely affecting a substantial
number of people.
11.3 GREENHOUSE GAS EMISSIONS
Impact 3.3.1 Would the project generate GHG emissions, either directly or indirectly?
Impact:
Less than Significant.
Finding:
The analysis in the SIR (Section 4.6.3, Greenhouse Gas Emissions) determined that Alternative
3 would result in less than significant impacts in relation to the generation of greenhouse gas
(GHG) emissions, either directly or indirectly. No mitigation measures are required.
Rationale:
Alternative 3 would increase long-term operational GHG emissions, but it would achieve the goals
and policies related to VMT reduction and access to open space articulated in the Southern
California Association of Governments' (SCAG) Connect SoCal.4 Implementation of the City's
Climate Action Plan (CAP) recommended measures, in addition to compliance with applicable
State regulations, would reduce GHG emissions from Alternative 3.
11.4 HYDROLOGY AND WATER QUALITY
Impact 3.4.1 Would the project substantially decrease groundwater supplies or interfere
substantially with groundwater recharge such that the project may impede
sustainable groundwater management of the basin?
Impact:
Less than Significant.
a Southern California Association of Governments. April 4, 2024. Connect SoCal.
https://scag. ca. gov/sites/main/files/file-attachments/23-2987-con nect-socal-2024-final-complete-
040424. pdf? 1714175547
Diamond
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Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page
II-5
Finding.
The analysis in the SIR (Section 4.6.4, Hydrology and Water Quality) determined that Alternative
3 would result in less than significant impacts to hydrology and water quality in relation to a
substantial decrease in groundwater supplies or interference with groundwater recharge such that
the project may impede sustainable groundwater management of the basin. No mitigation
measures are required.
Rationale:
Alternative 3 would include 40,000 square feet of open space. Alternative 3 would be required
to include Low Impact Development measures as required by the City of Diamond Bar in
accordance with California Regional Water Quality Control Board Order No. R4-2012-0175,
which regulates municipal discharges of storm water and non -storm water by the Los Angeles
County Flood Control District, the County of Los Angeles, and 84 incorporated cities within the
coastal watersheds of Los Angeles County with the exception of the City of Long Beach.
11.5 NOISE
Impact 3.5.1 Would the project generate a substantial temporary or permanent increase
in ambient noise levels in the vicinity of the project in excess of standards
established in the local general plan or noise ordinance, or applicable
standards of other agencies?
Impact.
Less than Significant.
Finding:
The analysis in the SIR (Section 4.6.5, Noise) determined that Alternative 3 would result in less
than significant impacts to noise in relation to generation of noise levels in excess of established
standards. No mitigation measures are required.
Rationale:
All future development would be required to comply with the restrictions of the Diamond Bar City
Code. If a project requests to deviate, the project proponent would need to obtain permission from
the City, including conditions and standards to minimize noise impacts. Future developments
under Alternative 3 would be required to comply with the Diamond Bar City Code, Section
8.12,720, Construction Noise. As such, future developments would be required to limit
construction hours for exterior construction and hauling activities to between the hours of 7:00
a.m. and 7:00 p.m., Monday through Saturday. These developments would be required to be
constructed such that the noise levels at the affected residential and commercial properties would
not exceed the maximum noise level limits for mobile and stationary construction equipment.
With respect to operational noise, Alternative 3 would not result in new significant operational
impacts greater than what was determined in the Certified General Plan EIR, and mitigation is
not required. Furthermore, as a result of the supplemental analysis regarding the generation of
noise levels in excess of local standards undertaken in this SIR, the land use refinements
Diamond
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Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page II-6
proposed in the Specific Plan would not result in new or substantially more adverse impacts on
noise than those evaluated for the Certified General Plan EIR,
Impact 3.5.2 Would the project generate excessive groundborne vibration or
groundborne noise levels?
Impact:
Less than Significant.
Finding:
The analysis in the SIR (Section 4.6.5, Noise) determined that Alternative 3 would result in less
than significant impacts in relation to generation of groundborne vibration or groundborne noise
levels.
Rationale:
Large bulldozers and loaded trucks are the equipment anticipated to be used within the Planning
Area that would generate the highest ground -borne vibration levels. The vibration analysis for the
Certified General Plan EIR calculated the minimum distance that large bulldozers and loaded
trucks could operate at for Class I through IV structures without causing significant damage (see
Table 3.5-10, Certified General Plan EIR Distances within Vibration Damage Criteria, in the Draft
SIR), The Certified General Plan EIR found that construction activities would be required to not
operate within the distance for each structure type shown in Table 3.5-10 in the Draft SIR to avoid
exceeding the vibration structural damage criteria. These construction distance requirements and
Section 8,12.840 of the Diamond Bar City Codes would apply to all future development under
Alternative 3.
Regarding operation impacts, as the vibration from vehicles is temporary and intermittent, and it
generates up to 0.005 inch per second (in/sec) peak particle velocity (PPV), which is well below
the threshold of perception for humans (0,035 in/sec PPV).
11.6 PUBLIC SERVICES
Impact 3.6.1 Would the project result in substantial adverse physical impacts associated
with the provision of new or physically governmental facilities, need for new
or physically altered government facilities, the construction of which could
cause significant environmental impacts, in order to maintain acceptable
service ratios, response times, or other performance objectives with respect
to parks?
Impact:
Less than Significant.
s Section 8.12.840 of the Diamond Bar City Code states, "Operating or permitting the operation of any device that
creates vibration which is above the vibration perception threshold of any individual at or beyond the property
boundary of the source if on private property, or at 150 feet (46 meters) from the source if on a public space or public
right -of --way is prohibited. The perception threshold shall be a motion velocity of 0.01 in/sec over the range of one to
100 Hertz."
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page II-7
Finding:
The analysis in the SIR (Section 4.6.6, Public Services) determined that Alternative 3 would result
in less than significant impacts to park -related public services and, thus, will not result in
substantial adverse physical impacts associated with the provision of new or physically altered
parks in order to maintain acceptable service ratios, response times or other performance
objectives. No mitigation measures are required.
Rationale:
Alternative 3 would increase population in line with the 0.6 percent overall population growth
outlined in the Certified General Plan EIR. This increased population could lead to a demand for
more parks. Alternative 3, however, is not anticipated to cause a substantial population increase.
Furthermore, as individual residential development projects are implemented, developers would
be required to comply with the Quimby Act and provide a dedication of land or in lieu of fees to
support the City's parkland standard, which would reduce these impacts.
Impact 3.6.2 Would the project result in substantial adverse physical impacts associated
with the provision of new or physically governmental facilities, need for new
or physically altered government facilities, the construction of which could
cause significant environmental impacts, in order to maintain acceptable
service ratios, response times, or other performance objectives for other
public facilities?
Impact:
Less than Significant.
Finding:
The analysis in the SIR (Section 4.6.6, Public Services, and Section 5.5, Impacts Found Not to
Be Significant) determined that Alternative 3 would result in less than significant impacts to other
public facilities, such as libraries, regarding capacity or service level, or resulting in substantial
adverse physical impacts associated with the provision of new or physically altered governmental
facilities in order to maintain acceptable service ratios, response times or other performance
objectives. No mitigation measures are required.
Rationale:
Fire prevention requires the Los Angeles County Fire Department to inspect all commercial
buildings in the City to detect fire and life hazards. In addition, the City adheres to the California
Building Code and Fire Code regarding fire safety, including standards for road widths and
access, as well as building standards (e.g., construction materials, sprinkler systeMS) 0617
Alternative 3 would comply with Los Angeles Fire Department standards, the Diamond Bar City
Code, and the California Building Code and Fire Code, which would ensure that fire protection
6 2022 California Building Code, Title 24. https://codes.iccsafe.org/content/CABC2022P1
California Building Standards Commission. 2023. Revision Record for the State of California. 2022 Title 24, Part 9,
California Fire Code. https://www.iccsafe.org/wp.content/uploads/errata_central/2022-California-Fire-Code-Part-9-
Errata-eff.-J an u ary-2023-55905221. pdf
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page II-8
capacity and service levels are maintained. Therefore, Alternative 3 would result in less than
significant impacts in relation to fire protection.
As discussed in the Certed General Plan EIR, support for crime prevention in the Planning Area
would be provided by the Crime Prevention through Environmental Design and other public safety
programs, which would help keep service demand increases to a minimum. Alternative 3 would
be a relatively compact/infill development contiguous to existing urbanized areas that are currently
served by existing police stations. In addition, General Plan 2040 policies regarding emergency
access and travel flow would ensure that emergency vehicles could efficiently access the
Planning Area, thereby reducing the need for new facilities. Therefore, Alternative 3 would result
in less than significant impacts in relation to police protection.
Alternative 3 is not anticipated to cause a substantial population increase beyond the anticipated
0.6 percent overall population growth rate for the City in the Housing Element 2021-2029.
According to the Pomona Unified School District (PUSD) Strategic Plan, PUSD has planned for
the economic development and increased capacity for corresponding enrollments as well as
student retention.8 Generally, student enrollment in the PUSD has been trending down.9 With that
pIan in place, the public schools in the PUSD have the capacity to absorb more students as the
population increases. Nonetheless, in accordance with SB 50 and PUSD Resolution No. 6 (2020-
21), "Authorizing the Imposition and Collection of Increased Developer Fees on New Residential
Construction," the PUSD would collect fees from new residential development to be used for
school facilities. For purposes of CEQA, these fees would constitute complete and full mitigation
of any potential impacts related to the demand for new or expanded school facilities. Therefore,
the refined project would result in less than significant impacts associated with the provision of
new or physically altered school facilities in order to maintain acceptable service ratios.
Under Alternative 3, future residents in the Planning Area would be served by the Diamond Bar
Library, located at 21810 Copley Drive. The Diamond Bar Library's Memorandum of
Understanding (MOU) (dated July 5, 2011) for operations allowed the County to relocate the
Diamond Bar Library into a larger and more modern facility. This updated facility improved library
services provided to City residents. Future potential property owners within the Planning Area
would pay County property tax. The County may, through property tax revenue, improve the
services provided within the existing Diamond Bar Library to adjust for the increase of residents
as a result of the development of Alternative 3.10 The improvements made from the capital
collected from the residential developments would work toward the Los Angeles County Library's
Strategic Plan for 2024. These improvements may further the County library's objectives, such as
ensuring safe meeting places for communities, maintaining pillars of service, and developing new
library advocates." Consistent with General Plan Policy PF-P-25, the City and the County would
continue to cooperate to ensure adequate provision of library services.
s Pomona Unified School District. 2015. Promise of Excellence: PUSD Strategic Plan 2015-2020.
https://4.fi les.edl. io/ca53/07/05l18/ 172730-f37a 1 a36-3e3f-434d-b959-eel a9053eb45. pdf
s Pomona Unified School District. 2015. Promise of Excellence: PUSD Strategic Plan 2015-2020.
https://4.files.edl.io/ca53/07/05/18/172730-f37al a36-3e3f-434d-b959-eel a9O53eb45.pdf
io County of Los Angeles Chief Executive Office. July 2011. Forty -Year Lease and Memorandum of Understanding
with the City of Diamond Bar: The Diamond Bar Library, 2180 Copley Drive, Diamond Bar.
LA County Library, 2024, Where Community Happens, Strategic Plan 2024-2028. https://lacountylibrary.org/wp-
content/uploads/2024/03/LACountyLibrary_Strategic_Plan_2024-28.pdf (accessed December 2, 2024).
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page II-9
1121 RECREATION
Impact 3.7.1 Would the Project 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?
Impact:
Less than Significant.
Finding:
The analysis in the SIR (Section 4.6.7, Recreation) determined that Alternative 3 would result in
less than significant impacts to recreation in relation to an increase of existing neighborhood and
regional parks or other recreational facilities such that substantial physical deterioration of the
facility would occur or accelerate. No mitigation measures are required.
Rationale:
Alternative 3 would have a significant impact on regional parks and recreational facilities if the
increased residential population would deteriorate existing facilities or require construction to
expand the existing parks. All parks and recreation facilities proposed as part of Alternative 3
would occur within the existing development footprint. Further, any development under
Alternative 3 would be required to comply with the Quimby Act and City regulations to address
the increased recreation facility demands. Payment of an in -lieu fee would be required, if the
development would create subdivisions (as discussed in Section 3.11, Recreation, of the Draft
SIR). This would ensure that additional demand for parks would not result in the physical
deterioration of existing parks and facilities within the City.
Impact 3.7.2 Does the project include recreational facilities or require the construction or
expansion of recreational facilities which might have an adverse physical
effect on the environment?
Impact:
Less than Significant.
Finding:
The analysis in the SIR (Section 4.6.7, Recreation) determined that Alternative 3 would result in
less than significant impacts to recreation in relation to adverse physical effects on the
environment as a result of proposed construction or expansion of recreational facilities. No
mitigation measures are required.
:I�-iR•T�Ft_ C�
All parks/recreational facilities proposed as part of Alternative 3 (including 40,000 sf of open
space) would occur within the existing development footprint, and potential impacts are accounted
for in the relevant sections throughout this SIR. Furthermore, future residential subdivisions under
the Quimby Act would contribute land or in lieu fees.
Diamond
Bar
Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page II-10
11.8 UTILITIES AND SERVICE SYSTEMS
Impact 3.9.1 Would the project require or result in the relocation or construction of new
or expanded water, wastewater treatment or storm water drainage, electric
power, natural gas, or telecommunications facilities, the construction or
relocation of which could cause significant environmental effects?
Impact; Less than Significant.
Finding:
The analysis in the SIR (Sections 3.9, Utilities and Service Systems, and 4.6.9, Utilities and
Service Systems) determined that Alternative 3 would result in less than significant impacts in
relation to the relocation or construction of new or expanded water, wastewater treatment or storm
water drainage, electric power, natural gas, or telecommunications facilities, the construction or
relocation of which could cause significant environmental effects. No mitigation measures are
required.
Rationale:
The Planning Area is served by the Walnut Valley Water District (WVWD). The majority of the
water supply is imported because of a lack of local potable groundwater. As determined in the
Certified General Plan EIR, although drought conditions will continue to pose potential issues for
water supply demand, a "drought -proof' recycled water system is used by parks and schools to
ease overall demand on the WVWD potable water system. Additionally, the refined project will
adhere to policies which promote water conservation (Diamond Bar Code of Ordinances §
8.14.010). Through various water conservation measures, the City's average annual water usage
from 2010 to 2015 steadily decreased. In the City of Diamond Bar General Plan Update Existing
Conditions Report — Volume III, it was projected that by 2035, the water supply will be
approximately 22,358 acre-feet (AF), while usage will be approximately 21,462 AF. In addition,
the Water Supply Assessment (WSA) prepared for the Diamond Bar Town Center Specific Plan
(SIR Appendix H) indicates that sufficient water supplies can be reasonably concluded to be fully
reliable and available to meet WVWD's existing demands and future demands through fiscal year
(FY) 2044-45. Based on these projections, it is anticipated that WVWD will sufficiently provide
potable water for the projected population growth in the City, including the land use development
scenario for Alternative 3.
The existing City sewer system within and around the region of Alternative 3 is comprised of
numerous sewer lines of varying sizes, slopes, and materials. The Los Angeles County Public
Health regulations for wastewater treatment systems, as required by statewide AB 885, set
standards for wastewater treatment and monitoring requirements. The local system of sewer lines
and pump stations feed two trunk sewer lines that convey wastewater to an LACSD treatment
facility.12 As a result, the demand for existing treatment infrastructure may be reduced and
potential impacts of any future decisions regarding the provisions of new infrastructure will be
considered. Alongside compliance with state and local regulations, impacts would be less than
significant. Therefore, no new or expanded wastewater treatment would be required for the
�2 City of Diamond Bar. 2023. City of Diamond Bar General Plan Update Existing Conditions Report —Volume III.
https://www.diamondbarca.gov/DocumentCenterNiew/7518/General-Plan-Existing-Conditions-Report---Volume-
III 011017?bidld=
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page II-11
implementation of Alternative 3. Further, the Certified General Plan EIR noted that conversation
methods to curb demand, ensure coordinated planning for provisions of public facilities including
water and wastewater infrastructure and ensure facilities be designed and constructed to preserve
the natural character of the Planning Area would reduce the demand on wastewater infrastructure.
WVWD'S water supply sources currently include treated and untreated, imported surface water
purchased from MWD through Three Valleys Municipal Water District. Per the WSA (SIR
Appendix H), the additional water usage by the refined project would range from about 18.9 and
20.1 million gallons a day (MGD) and, consequently, it is anticipated that the Three Valleys
Municipal Water District would have sufficient capacity from its imported sources to meet its
average day demands over the next 20 years, inclusive of the Alternative 3 land use scenario.
Alternative 3's potential impacts would be offset by local, regional, and statewide mandates for
solid waste reduction, water availability assessments, and required wastewater treatment
capacity assessments. Applicable statewide regulations regarding waste management include
the State Mandatory Organic Waste Collection (SB 1383), Mandatory Commercial Recycling
Regulation (AB 341) and California Solid Waste Reuse and Recycling Act (AB 939) as well as
SB 6101 SB 221 and SB 1262 (amending Sections 10910-10915 of the State Water Code).
Impact 3.9.2 Would the project have sufficient water supplies available to serve the
Project and reasonably foreseeable future development during normal, dry,
and multiple dry years?
Impact: Less than Significant.
Finding:
The analysis in the SIR (Section 4.6.9, Utilities and Service Systems) determined that Alternative
3 would result in less than significant impacts in relation to sufficient water supplies available to
serve reasonably foreseeable future development during normal, dry and multiple dry years. No
mitigation measures are required.
Rationale:
As discussed in the WSA (Appendix H to the SIR), the Specific Plan would result in a net
additional water demand during an average/normal year of up to 372 acre-feet per year (AFY)
by FY 2044-45. WVWD's estimated water demands are projected to be approximately 21,803
AFY by FY 2044-45. Based on the demonstrated reliability of WVWD's combined water supply
sources in the United States, sufficient water supplies can be fully reliable and available to meet
WVWD's existing demands and future demands through FY 2044-45, including during single
and multiple dry years (i.e., 5 consecutive dry years).
Furthermore, each entitlement request within the Planning Area will submit a Water Availability
Request application to the water purveyor for them to perform flow tests and hydraulic analysis
of their water system to determine if adequate domestic and fire water flows and pressures are
available in the Planning Area.
Diamond
Bar
Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page II-12
Impact 3.9.3 Would the project result in a determination by the wastewater treatment
provider which serves or may serve the Project that it has adequate capacity
to serve the Project's projected demand in addition to the provider's existing
commitments?
Impact: Less than Signcant.
Finding:
The analysis in the SIR (Section 4.6.9, Utilities and Service Systems) determined that Alternative
3 would result in less than significant impacts in relation to the capacity of wastewater treatment
facilities. No mitigation measures are required.
Rationale:
The development of Alternative 3 would generate wastewater and would require sanitary sewer
wastewater treatment. However, goals and policies proposed in the General Plan aim to conserve
water by curbing demand for domestic and commercial purposes, promoting water conservation
strategies, and ensuring coordinated planning from the provision of public facilities including water
infrastructure. Current regulations require compliance with water quality standards and would not
allow development without adequate utility capacity, including wastewater treatment capacity.
The future development that would occur as a result of Alternative 3 would be reviewed by the
City and Los Angeles County Sanitation Districts to determine that sufficient capacity exists to
serve the development.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page II-13
III POTENTIAL ENVIRONMENTAL EFFECTS THAT
CAN BE MITIGATED TO A LEVEL OF
INSIGNIFICANCE
The analysis undertaken in support of the SIR for the Specific Plan did not identify any potentially
significant impacts that were able to be reduced to a level of insignificance after the consideration
of feasible alternatives and mitigation measures,
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page III-1
IV SIGNIFICANT UNAVOIDABLE ADVERSE IMPACTS
THAT CANNOT BE MITIGATED BELOW THE
LEVEL OF SIGNIFICANCE
The Final SIR determined that implementation of Alternative 3 would result in the following
significant environmental effects, which, even after application of feasible mitigation measures
and compliance with existing statutes, regulations, uniform codes, and project features, cannot
be mitigated to below a level of significance and therefore will remain significant and unavoidable.
Findings supporting the determinations are provided below.
IV.1 Air Quality
Operation
Impact 3.2.2 Would the project result in a cumulatively considerable net increase of any
criteria pollutant for which the project region is non -attainment under an
applicable federal or state ambient air quality standard?
Impact:
Significant and Unavoidable for Operations.
Finding:
The analysis in the Final SIR determined that Alternative 3 would result in significant and
unavoidable impacts to air quality during the operational phase of the project in relation to a
cumulatively considerable net increase of any criteria pollutant for which the project region is non -
attainment under an applicable federal or state ambient air quality standard.
Rationale:
The Certified General Plan EIR found that the 2022 Housing and Land Use Element Update would
exceed South Coast Air Quality Management District (SCAQMD) significance thresholds for
volatile organic compounds (VOCs) and nitrous oxide (NOX) and that construction and operational
impacts would be significant and unavoidable.
Alternative 3 would reduce the construction footprint by dedicating 40,000 square feet (sf) to open
space.
Alternative 3 includes the same land use planning scenario evaluated in Section 3.2, Air Quality,
of the SIR, differing only in the exclusion of the road diet.
Unmitigated Alternative 3 would be below the SCAQMD threshold for criteria pollutants in all
categories except reactive organic gases (ROGs) and particulate matter 2.5 microns or less in
diameter (PM2.5) (see Table 4.6-3, Alternative 3: Unmitigated Operations Emissions Threshold
Evaluation, of the SIR). However, Alternative 3 has reduced emissions for all criteria pollutants
when compared to the land use planning scenario evaluated in the Certified General Plan EIR for
all criteria pollutants, except ROGs (which were not evaluated in the Certified General Plan EIR)
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page IV-1
and PM2.5. As demonstrated in the SIR, operational impacts of mitigated Alternative 3 are reduced
to below the SCAQMD significance threshold for operations for all categories, except ROGs and
PM2.5. Alternative 3 would be below the SCAQMD threshold for criteria pollutants in all categories
except ROGs and PM2.5 (see Table 4.64, Alternative 3: Mitigated Operations Emissions
Threshold Evaluation, of the SIR). Only emissions of PM2.5 for Alternative 3 remain above the
SCAQMD significance operations thresholds even after the consideration of mitigation (Table 4.6-
4). Although emissions of PM2.5 for Alternative 3, at 56.49 pounds per day (1.48 pounds per day
above the threshold), remain significant and unavoidable, emissions are substantially reduced
from the 352 pounds per day for the approved land use planning scenario in the Certified General
Plan EIR.
The following mitigation measures have been identified in the SIR to reduce this impact:
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.'
• 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 or
equivalent.
• Require a minimum of 50 percent of construction debris to 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.
MM-AQ-2: Future Development. Future development would be required to demonstrate
consistency with SCAQMD's operational thresholds. For projects where operational emissions
exceed regulatory thresholds, the following measures may be used to reduce impacts. Note the
following measures are not all inclusive and developers have the option to add or substitute
measures that are equally or more appropriate for the scope of their project.
• Develop a project specific Transportation Demand Management (TDM) program for
residents and/or employees that provides opportunities for carpool/vanpools.
• Provide onsite solar/renewable energy in excess of regulatory requirements.
• Require that owners/tenants of non-residential or multi -family residential developments
use architectural coatings that are 10 grams per liter or less when repainting/repairing
properties.
• Require dripless irrigation sensor units that prevent watering during rainstorms.
MM-AQ-3: The SCAG Mitigation Monitoring and Reporting Program (MMRP) forthe final Connect
SoCal PEIR provides guidance for lead agencies in the consideration of project -level mitigation
' City of Diamond Bar. 2019. Diamond Bar Comprehensive General Plan Update and Climate Action Plan Draft
Environmental Impact Report. https://ceganet.opr.ca.gov/2018051066/2
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page IV-2
measures to reduce substantial adverse effects related to a violation of air quality standards, in
accordance with sections 15091(a)(2) and 15126.4(a)(1)(B) of the State CEQA Guidelines, The
City shall consider implementation of the following measures to reduce impacts, including (but not
limited to):2
• Suspend grading and earthmoving when wind gusts exceed 25 miles per hour unless the
soil is wet enough to prevent dust plumes.
• Cover trucks when hauling dirt.
• Require projects to use Tier 4 Final equipment or better for all engines above 50
horsepower (hp). In the event that construction equipment cannot meet to Tier 4 Final
engine certification, the project representative or contractor must demonstrate through
future study with written findings supported by substantial evidence that is approved by
SCAG before using other technologies/strategies.
MM-AQ-4: Per the CAPCOA Handbook,3 the City shall implement the following measure to
reduce construction emissions further for Alternative 3:
• C-3: Use Local Construction Contractors
MM-AQ-5: Per the CAPCOA Handbook,4 the City shall implement the following measures to
reduce operation emissions further for Alternative 3, including (but not limited to):
• E-2: Require Energy Efficient Appliances
• E-12-A: Install Alternative Type of Water Heater in Place of Gas Storage Tank Heater in
Residences
• E-12-B: Install Electric Space Heater in Place of Natural Gas Heaters in Residences
• E-13: Install Electric Ranges in Place of Gas Ranges
• E-15: Require AII-Electric Development
• T-23: Community -Based Travel Planning
• ASA: Use Low-VOC Cleaning Supplies
• AS-2: Use Low-VOC Paints
• LLA: Replace Gas Powered Landscape Equipment with Zero -Emission Landscape
Equipment
MM-AQ-6: The CAPCOA Handbooks also offers qualitative or supporting measures. The
Alternative 3's Mobile and Area emissions are the two most prominent sources of operational Air
Quality emissions based on the best available data. The City shall consider implementation of the
2 Southern California Association of Governments. May 2020. MMRP for the Connect SoCal Final PEIR.
https: //scag. ca.gov/sites/main/fi lesJfile-attachments/exh i
a_connectsocal_peir, pdf#: :text=M/o20is%20the°/o20i menLw20or/o20this9/o20prog ram°/o20to°/o3A, and°/o20°/o287%29
%20utilize%20existing%20review%20processes%20wherever%20feasible.
s California Air Pollution Control Officers Association, December 2021. Handbook for Analyzing Greenhouse Gas
Emission Reductions, Assessing Climate Vulnerabilities, and Advancing Health and Equity.
https:Hcaleemod.com/documents/handbook/full_handbook. pdf
4 California Air Pollution Control Officers Association, December 2021. Handbook for Analyzing Greenhouse Gas
Emission Reductions, Assessing Climate Vulnerabilities, and Advancing Health and Equity,
https:Hcaleemod.com/documents/handbook/full_handbook. pdf
a California Air Pollution Control Officers Association, December 2021. Handbook for Analyzing Greenhouse Gas
Emission Reductions, Assessing Climate Vulnerabilities, and Advancing Health and Equity,
https:Hcaleemod.com/documents/handbook/full_handbook. pdf
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page IV-3
following supporting measures to reduce transportation emissions further for Alternative 3,
including (but not limited to):
• T-30: Using cleaner -fueled vehicles.
• T-18: Provide Pedestrian Network Improvement.
• T-13: Implement Employee Parking Cash -Out.
• T-21-A: Implement Conventional Carshare Program.
MM-AQ-7: The City shall consider implementation of the following CAPCOA Handbook
supporting measure to reduce Area emissions:
• LL-2: Implement a yard equipment exchange program, which would require Alternative
3 to participate in an established yard equipment exchange program, supplement an
established program, or implement a new program.
The unmitigated operational phase of Alternative 3 would result in significant emissions of two
criteria pollutants: ROGs and PM2.5 (see SIR Table 4.6-3). The implementation of MM-AQ-1, MM-
AQ-2, MM-AQ-3, MM-AQ-4, MM-AQ-5, MM-AQ-6, and MM-AQ-7 would reduce air quality
impacts in relation to cumulatively considerable net increase of four criteria pollutants—NOx, CO,
S02, and PMio—for which the region is in non -attainment under the National Ambient Air Quality
Standards or California Ambient Air Quality Standards to below the SCAQMD significance
operation thresholds. Emissions of ROGs and PM2.5 would exceed the SCAQMD threshold of
significance, causing operational emissions of criteria pollutants to remain significant and
unavoidable. However, the operational emission of NOX, CO, PM2.5, and PMJo would be
substantially lower than those evaluated in the land use planning scenario for the General Plan
2040.
Significant and unavoidable impacts of the operational phase of the project necessitate a
statement of overrng consideration (see Section X, CEQA Guidelines Section 15093 Findings:
Statement of Overriding Considerations).
Impact 3.2.3 Would the project expose sensitive receptors to substantial pollutant
concentrations?
Impact:
Significant and Unavoidable for Operation.
Finding:
The analysis in the Final SIR determined that Alternative 3 would result in significant and
unavoidable impacts to air quality in relation to exposing sensitive receptors to substantial
pollutant concentrations during the operational phase of the project.
Rationale:
Although Alternative 3 results in significant and unavoidable impacts to sensitive receptors as a
result of exposure to criteria pollutants in excess of the SCAQMD significance operational
thresholds, the operations emissions would be substantially lower than that evaluated for the
Certified General Plan EIR maximum daily operations thresholds. The Certified General Plan EIR
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page IV-4
found that the 2022 Housing and Land Use Updates would expose sensitive receptors to
substantial pollutant concentrations and that operational impacts from NOx, CO, PM2.5, and PM,o
would be significant and unavoidable (see Table 4.6-3, Alternative 3: Unmitigated Operations
Emissions Threshold Evaluation, and Table 4.64, Alternative 3: Mitigated Operations Emissions
Threshold Evaluation, of the SIR). ROGs were not evaluated in the Certified General Plan EIR.
The unmitigated operational impacts of criteria pollutants for NOx, CO, and PM1ofor Alternative 3
would be below the SCAQMD significance operations thresholds. Only emission of PM2.5 for
Alternative 3 would remain above the SCAQMD significance operations thresholds even after the
consideration of mitigation (Table 4.6-4). Although emissions of PM2.5 for Alternative 3, at 56.49
pounds per day (1.48 pounds per day above the threshold), remain significant and unavoidable,
emissions are substantially reduced from the 352 pounds per day for the approved land use
planning scenario in the Certified General Plan EIR.
Alternative 3 includes the same land use development scenario evaluated in Section 3.2, Air
Quality, of the SIR, for the refined project. Alternative 3 and the refined project differ only in that
Alternative 3 does not include the road diet provided as an element of the refined project. As such,
the construction scenario for Alternative 3 differs only in that the lane configuration, median, and
sidewalks for Diamond Bar Boulevard within the Planning Area would remain in their baseline
condition (see SIR Table 4.6-1, Alternative 3: Overall Estimated Daily Construction Emissions by
Year [Unmitigated], and Table 4.6-2, Alternative 3: Overall Estimated Daily Construction
Emissions by Year [Mitigatedb. As such, the findings in Section 3.2 would be comparable to the
Alternative 3 findings for construction.
Alternative 3 would have a corresponding reduction in the impacts of criteria pollutants for
sensitive receptors, particularly those that live within one-half mile of the Planning Area, or those
that would travel via bicycle or bus through the Specific Plan Area.
Implementation of MM-AQ-1, MM-AQ-2, MM-AQ-3, MM-AQ-4, MM-AQ-5, MM-AQ-6, and MM-
AQ-7, as listed above, would be required to reduce this impact.
The implementation of MM-AQ-1, MM-AQ-2, MM-AQ-3, MM-AQ-4, MM-AQ-5, MM-AQ-6, and
MM-AQ-7 would reduce air quality impacts in relation to cumulatively considerable net increase
of criteria pollutants for which the region is in non -attainment under the National Ambient Air
Quality Standards or California Ambient Air Quality Standards to below SCAQMD threshold of
significance for four criteria pollutants: NO, CO, S02, and PM,o (see Table 4.6-4, Alternative 3:
Mitigated Operations Emissions Threshold Evaluation, in the SIR). Operational emissions of
ROGs and PM2.5 would exceed the SCAQMD operations significance threshold, causing
operational emissions of criteria pollutants to remain significant and unavoidable (Table 4.6-4).
However, the operational emission of NOx, CO, PM2.5, and PM10 would be substantially lower than
those evaluated in the land use planning scenario for the approved General Plan 2040 (Table
4.6-4).
Significant and unavoidable impacts of the operational phase of the project necessitate a
statement of overriding consideration (see Section X, CEQA Guidelines Section 15093 Findings:
Statement of Overriding Consideration).
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page IV-5
IV.2 Transportation
Impact 3.8-1 Would the project conflict with or be inconsistent with CEQA Guidelines
Section §15064.3, subdivision (b)?
Significant and Unavoidable.
Finding:
The analysis in the Final SIR determined that Alternative 3 would result in significant and
unavoidable impacts to transportation in relation to conflicting with or being inconsistent with
CEQA Guidelines Section 15064.3, Subdivision (b).
Rationale:
The Certified General Plan EIR determined that impacts would be significant and unavoidable in
relation to conflicting with or being inconsistent with CEQA Guidelines Section 15064.3,
Subdivision (b), as implementation of the Diamond Bar General Plan 2040 would increase both
resident and employee VMT per capita on a citywide basis, even with the City's goals and policies
to reduce potential impacts. No mitigation was identified in the Certified General Plan EIR.
Alternative 3 would not include a road diet. TDM measures (Mitigation Measure MM-TRANS-1)
would be implemented with Alternative 3. Nonetheless, VMT would likely increase with Alternative
3, compared to the Certified General Plan EIR, because there would be no road diet to slow
vehicle speeds, reduce traffic volume, and improve safety for all road users. Therefore, compared
to the Certified General Plan EIR, Alternative 3 would similarly result in significant and
unavoidable VMT impacts, but impacts would be greater than under the Certified General Plan
EIR because there would be no road diet.
The following Mitigation Measure has been identified in the SIR to reduce this impact:
MM-TRAN4Z-1: TDM Program. The Alternative 3 shall incorporate design features and
transportation demand management (TDM) measures known to reduce baseline and cumulative
project -generated VMT as much as feasible. These features and measures, originally described
in the Transportation Study for the Diamond Bar Town Center Specific Plan project, comprise the
project's TDM Program, The TDM Program conforms to VMT mitigation guidelines found in City
of Diamond Bar Transportation Study Guidelines for Vehicle Miles Traveled and Level of Service
Assessment (September 2020).
Some components of the TDM Program consist of physical features of Alternative 3's design
which shall be implemented over the duration of buildout of Alternative 3. Others which have an
operational component will be implemented as early as feasible based on the land use mix and
infrastructure as the project is built over time. The City shall designate a TDM Coordinator to
oversee implementation and ensure continued operation of the VMT reduction strategies. The
TDM Coordinator shall also produce annual monitoring reports describing the TDM strategies
implemented under the TDM Program and the effectiveness of the program. The reports shall be
submitted to the City for review to ensure that the mitigation obligations described in the TDM
Program Plan are fulfilled, The TDM Coordinator position — which may be part-time or full-time
Diamond
Bar
Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page
IV-6
as deemed necessary — shall eventually be funded through fees paid by the developers for
common area maintenance and management.
Each feature and measure is described in detail below, along with its implementation schedule,
measure of effectiveness, and monitoring and reporting requirement:
• Increased Bicycle Access: Through the City's Complete Streets Project (being undertaken
separately from Alternative 3), Alternative 3 shall incorporate Class IV protected bicycle
lanes on Diamond Bar Boulevard, Grand Avenue Golden Springs Drive, and Prospectors
Road and a Class III bicycle lane on Sunset Crossing Roads. This improvement from
unprotected to protected bicycle lanes reduces stress for bicyclists and, therefore,
encourages bicycles as a mode choice. These bicycle lanes would be implemented as part
of the Alternative 3, which would dictate its timing. Aside from ensuring it is included in the
Alternative 3, there is no further monitoring or reporting requirement for this measure.
• Bike Facilities: The TDM Program shall include secure bicycle parking for residents and
employees per City requirements. Each application for development under the Diamond
Bar Town Center Specific Plan will be required to demonstrate that it provides bicycle
parking in accordance with City requirements. The annual monitoring report would
summarize how many bicycle parking spaces have been installed within the Planning Area.
• First -Mile / Last -Mile Space: The TDM Program shall dedicate space in a central location
for first mile / last -mile solutions such as bike share, scooter share, or a future mode to
serve medium -distance trips to larger transit hubs, such as the City of Industry Metrolink
Station, located approximately 3.3 miles away. This space, which may be located in a
parking structure, a building, or outside, will be set aside and constructed prior to receiving
certificate of occupancy for 50% of allowed development (measured in square feet) under
the Diamond Bar Town Center Specific Plan. Further, the TDM Coordinator will work with
one or more service providers to populate the space with first -mile / last -mile solutions made
available to the public. Prior to construction of this space, the annual monitoring report will
track the amount of development that has occurred under the Diamond Bar Town Center
Specific Plan to ensure the space is provided on schedule. Following its construction, the
annual monitoring report will identify the services provided, pricing, and the level of
utilization on a monthly basis over the prior year. Based on the Transportation Study, there
is no target level of utilization for these services. However, the TDM Coordinator should
periodically review the costs and benefits of the program compared with the level of
utilization and, if necessary, identify alternative types of services that may be provided within
this space to more effectively reduce VMT.
• Improved Pedestrian Network: This TDM Program includes the development of new
connections within the Planning Area and connecting to other areas. The refined project
would improve pedestrian connectivity within the Planning Area such as between the portion
of the site fronting Golden Springs Drive and the portion of the site fronting Diamond Bar
Boulevard, which is currently blocked by buildings, landscaping, and a grade differential. It
would improve pedestrian connectivity to the surrounding areas, including by providing a
connection to Prospectors Road and the residential neighborhood it serves. These features
enhance walkability and accessibility. These pedestrian network connections are
fundamental to the design guidelines incorporated into the Diamond Bar Town Center
Specific Plan and will be implemented gradually throughout the duration of buildout. There
is no further monitoring or reporting requirement for this measure.
• Car Sharing Program or Rideshare Subsidies: The TDM Program shall either provide
parking spaces and subsidies for car sharing services such as ZipCar, Car2Go, GetAround,
etc. or the TDM Coordinator may develop agreements with one or more rideshare
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page IV-7
companies (e.g., Uber or Lyft) to provide subsidized rides for eligible residents and
employees to or from the Planning Area. Such programs allow residents to forego car
ownership but still have a vehicle available for certain types of trips where walking, bicycling,
carpooling, or transit are not reasonable options. If the car sharing service option is
selected, spaces shall be set aside upon construction of any parking structure in the
Planning Area and the TDM Coordinator will work with a service provider to provide a car
sharing solution with at least two vehicles. The efficacy of the program shall be measured
by the number of uses per month per vehicle. If the vehicles are used an average of two or
more times per day, the TDM Coordinator should consider adding to the fleet. If the vehicles
are used fewer than one time per day on average, the TDM Coordinator should consider
additional marketing or reducing the fleet. If a rideshare agreement is made in lieu of a car
sharing service, it shall be implemented prior to receiving a certificate of occupancy for 30%
of allowed development under the Diamond Bar Town Center Specific Plan and would be
open to all residents and employees within the Planning Area. The program should target
participation on a monthly basis by at least 5% of households and 1 % of employees. If
participation is below these levels, the TDM Coordinator should consider additional
marketing or increasing subsidies. The annual monitoring report will include a summary of
the services offered and prices (or subsidy amounts) and a summary of utilization on a
monthly basis, including the number of unique users.
• Commute Trip Reduction Marketinq & Education: The TDM Program shall implement a
marketing campaign for project employees and visitors encouraging the use of transit,
shared rides, and active modes to reduce VMT. The TDM Program would target this
campaign at employees, residents, and visitors to the Planning Area. This campaign would
be implemented following certificate of occupancy for 30% of allowed development under
the Diamond Bar Town Center Specific Plan. The annual monitoring reports shall include a
copy of all marketing and educational materials and a summary of any outreach efforts from
the prior year.
• Employee Parking Cash -out: The TDM Program shall charge employers for employee
parking and employers will be required to reimburse employees for the cost of parking if
they don't park a car at work. This provides a direct monetary benefit to the employee for
choosing alternative travel modes and has been shown to reduce VMT. Paid employee
parking cannot begin until parking areas are converted to controlled access which will not
occur until one or more parking structures are completed. Therefore, employee parking
cash -out shall begin upon commencement of paid employee parking. The efficacy of the
employee parking cash -out program should be measured as the ratio of the number of
employees taking advantage of the cash -out program to the number of leased spaces by
employers. The program should target a 2% participation rate in accordance with the level
of employee VMT reduction estimated in the Transportation Study. The annual monitoring
report shall include the numbers used to calculate the participation rate as well as
information on parking pricing. If the target participation rate is not met, corrective measures
should be implemented by the TDM Coordinator, such as enhanced marketing of the
program or raising the price of parking.
• Unbundled Residential Parking: The TDM Program shall require parking to be leased to
residents separately from their residential unit leases. This makes the cost of automobile
storage transparent to residents, provides a direct monetary benefit to living without owning
a vehicle, and reduces VMT by encouraging alternate modes of transportation. To ensure
effectiveness, the TDM Program shall require pairing with the implementation of a
residential parking permit program in nearby residential neighborhoods to avoid shifting
project resident parking into those neighborhoods. Unbundled residential parking will be
incorporated into any and all residential development under the Diamond Bar Town Center
Specific Plan. The efficacy of the unbundled residential parking program should be
Diamond Bar Town Center Specific Plan
February 25, 2026
Findings of Fact and Statement of Overriding Considerations
Page IV-8
measured as the ratio of the number of leased residential spaces compared to the parking
requirement associated with the residential units, as calculated based on the City Code of
Ordinances, Section 22.30.040 accounting for the specific unit mix. The target ratio should
be 95% or lower (i.e., 5% lower lease rate than required parking ratio) in accordance with
the level of residential VMT reduction estimated in the Transportation Study. The annual
monitoring report shall include the numbers used to calculate the residential parking ratio
as well as information on parking pricing. If the target ratio is not met, residential parking
pricing should be increased and marketing and education efforts to residents regarding
alternative modes of transportation should be increased.
The ultimate goal of the TDM Program is to reduce VMT in the most effective manner possible,
which may require periodic re-evaluation of the measures described above. The TDM Coordinator
shall use the information compiled in the annual reports to evaluate the effectiveness of the
operational measures and assess when a change is warranted. Any change to the TDM Program
must be reviewed and approved by City staff through a determination that it will provide equivalent
or greater VMT reduction than the measure(s) being replaced.
With the implementation of MM-TRANS-1, impacts would remain significant and unavoidable in
relation to baseline and cumulative project -generated VMT under Alternative 3.
Significant and unavoidable impacts of the operational phase of the project necessitate a
statement of overriding consideration (see Section X, CEQA Guidelines Section 15093 Findings:
Statement of Overriding Consideration).
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page IV-9
V FINDINGS REGARDING RECOMMENDED
PROJECT AND ALTERNATIVES NOT
RECOMMENDED FOR ADOPTION
In April 2021, the Urban Land Institute -Los Angeles (ULI-LA) convened a Technical Assistance
Panel (TAP) to prepare the Technical Assistance Panel Report: Diamond Bar Town Center (TAP
Report).' The focus of the TAP Report was the consideration of market possibilities,
implementation strategies, and design frameworks for implementing the Town Center defined in
the General Plan, A Town Center Specific Plan was recommended to provide detailed
development standards, infrastructure requirements and implementation measures for the Town
Center. As part of the TAP's Town Center Specific Plan analysis, the real estate economics firm
RCLCO Real Estate Consulting prepared a market feasibility study for the Town Center, which
concluded that (1) market demand exists for over 2,000 housing units (an average of 44 units per
acre), including more than 1,500 rental units of varying product types, based on market conditions,
demographics and locational advantages in Diamond Bar; (2) a strong opportunity is presented
for redevelopment and repositioning of existing retail space, which would benefit from synergies
created by new housing; and (3) there is low demand for office development in the area.2
The market feasibility study also mentioned the commitment to the Complete Streets Project and
the importance of future roadway improvements.0 "California passed the California Complete
Streets Act (Complete Streets) in 2008, requiring circulation elements to include a complete
streets approach that balances the needs of all users of the street."' Complete Streets policies
and framework have been required to be part of a City General Plan Circulation Element since
January 30, 2011. Complete Streets are streets that are designed, constructed, operated,
maintained, and are compatible with adjacent land uses as a balanced, multi -modal transportation
network enabling safe comfortable, and attractive access to all users regardless of their
transportation mode, ability, or age .5 The Complete Streets approach was incorporated and
adopted into the City's General Plan in 2019.E Under the Complete Streets approach, the City's
roadways are characterized based on "through movement" and "level of access," both of which
are requirements for complying with this approach towards mobility.
In November 21, 2023, the City Council authorized funds to incorporate improvements that are
elements of the Diamond Bar Complete Streets Project, for Diamond Boulevard, between Golden
Springs Drive and Palomino Drive, including elements that enhance multi -modal transportation,
' Urban Land Institute -Los Angeles. April 2021. Technical Assistance Panel Report: Diamond Bar Town Center.
https://www.d iamondbarca.gov/DocumentCenterNiew/8250/Diamond-Bar-Town-Center-Report-Apri12021 ?bidld=
(accessed March 10, 2023),
2 RCLCO Real Estate Consulting. Existing Conditions & Market Demand Analysis: Diamond Bar Town Center for the
Cit of Diamond Bar, California. September 6, 2022,
3 RCLCO Real Estate Consulting, Existing Conditions & Market Demand Analysis: Diamond Bar Town Center for the
Cit of Diamond Bar, California. September 6, 2022,
4 City of Diamond Bar. 2019. City of Diamond Bar General Plan 2040.
https://www.diamondbarca.gov/DocumentCenterNiew/7072/Diamond-Bar-General-Plan-2040?bidld=
5 City of Diamond Bar. 2019. City of Diamond Bar General Plan 2040.
https://www,diamondbarca.gov/DocumentCenterNiew/7072/Diamond-Bar-General-Plan-2040?bidld=
6 City of Diamond Bar. 2019. City of Diamond Bar General Plan 2040: Circulation Element.
https://www,diamondbarca.gov/DocumentCenterNiew/7072/Diamond-Bar-General-Plan-2040?bidld=
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 202E Page V-1
stormwater treatment, and decorative street amenities.' The City successfully secured funding for
Diamond Bar Complete Streets Project elements between Golden Springs Drive and Palomino
Drive from multiple sources, including Los Angeles County Metropolitan Transportation Authority
(LACMTA) Regional Measure Multi -year Subregional Program; California Transportation
Commission Active Transportation Planning Organization Cycle 6; and LACMTA-administered
Caltrans-Managed Federal Surface Transportation Program -Local. (subsequently replaced with
Proposition C funds). On December 17, 2024, the City adopted a categorical exemption for the
Complete Streets project.8 On September 23, 2025, the City advertised for construction bids for
the Diamond Bar Boulevard Complete Streets project elements. The recommended contractor
was presented to the City Council for approval on November 4, 2025. The City Council approved
the project and Construction Agreement via Resolution No. 2025-34. Construction of the
Complete Streets Project is scheduled to be initiated in February 2026.9
V.1 Range of Reasonable Alternatives
Section 15126.E of the State CEQA Guidelines requires the evaluation of a range of reasonable
alternatives to the project, or to the location of the project that would feasibly attain most of the
basic objectives of the project but would avoid or substantially lessen any of the significant project
effects. The analysis of alternatives is limited to those that the City determines could feasibly attain
most of the basic objectives of the project. Section 15126.6(f) of the State CEQA Guidelines
describes feasibility as being dependent on several factors, including site suitability, economic
viability, availability of infrastructure, specific plan consistency, consistency with other plans or
regulatory limitations, jurisdictional boundaries, and the ability of the project proponent to gain
access to or acquire an alternative site.
In light of the TAP Report's findings,'° the market feasibility study prepared by RCLCO Real Estate
Consulting" to support the TAP Report, and the City's Complete Streets Project, the City identified
the High Density, Maximum Buildout with Road Diet version of the Specific Plan, evaluated in the
SIR as the "refined project," as it refined the land use scenario for the Planning Area that was
adopted in General Plan 2040, as amended by 2021-2029 Housing Element) as the proposed
project for evaluation in the SIR. Consistent with the requirements of Section 15126.9(e)(2) of the
CEQA Guidelines, a No -Project Alternative was analyzed representing what would be reasonably
expected to occur in the foreseeable future if the project or action alternative is not adopted and
implementation of the Town Center is undertaken consistently with the 2021-2029 Housing
� City of Diamond Bar. November 21, 2023. First Amendment to the Professional Services Agreement with MNS
Engineers, Inc. for the Design of Diamond Bar Complete Street Project (CIP# PW17400). City Council Agenda
Report. Prepared by Daniel Fox, City Manager, for Honorable Mayor and Members of the City Council.
a City of Diamond Bar. December 17, 2024. Adopt Resolution Authorizing Execution of Funding Agreements for State
and Federal Funding, Approve V VWD Utility Agreement, Approve LACFCD Trash Excluder Agreement and Adopt a
Class 1 CEQA Exemption for the Diamond Bar Boulevard Complete Streets Project. City Council Agenda Report.
Prepared by Daniel Fox, City Manager, for Honorable Mayor and Members of the City Council.
s City of Diamond Bar, November 4, 2025. Award of Construction Agreement for the Diamond Bar Boulevard
Complete Streets Project - CIP No. S1256 (Gentry Brothers, Inc.) and Approval of Amendment 2 to a Professional
Services Agreement for Construction Management and Inspection Services (Local Agency Engineering Associates,
Inc.). City Council Agenda Report. Prepared by Daniel Fox, City Manager, for Honorable Mayor and Members of the
City Council.
10 City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
Apri12021?bidI& . Accessed January 13, 2026.
" RCLCO Real Estate Consulting. Existing Conditions & Market Demand Analysis: Diamond Bar Town Center for the
'it of Diamond Bar, California. September 6, 2022.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 202E Page V-2
Element Update. The No -Project Alternative was not analyzed as keeping the property in the
existing conditions (as of 2023) would be inconsistent with Diamond Bar Town Center planning
objectives. As required by Section 15126.6 of the CEQA Guidelines, three additional alternatives,
representing a reasonable range of alternatives, that are responsive to the TAP Report and
supporting market feasibility study were defined: Alternative 1 (Medium Density with Road Diet),
Alternative 2 (Low Density with Road Diet), and Alternative 3 (High Density, No Road Diet).
Alternatives 1 and 2 reduced the density of dwelling units, reduced the number of hotel rooms,
and reduced the maximum allowable retail/commercial area, while retaining the open space, road
diet and bicycle lanes that were elements of the refined project. Alternative 3 retained the dwelling
units, hotel room, retail/commercial area, open space, and bicycle lanes evaluated for the refined
project and deleted the road diet evaluated for the refined project, leaving Diamond Bar in a
comparable configuration within the Planning Area. Alternative 3 provides a balance of land uses
that would achieve the highest number of housing units and hotel rooms, square footage of
retail/commercial space, and square footage of open space within the Planning Area; retains
Diamond Bar Boulevard in a comparable condition to its existing condition; retains sidewalks
adjacent to Diamond Bar Boulevard; and adds Class IV and Class III bicycle lanes. In addition,
Alternative 3 is able to accommodate the bicycle lane improvements contemplated by the City's
Complete Streets Project. As a result of the analysis contained in the SIR regarding the
environmental, health, and social characteristics of the project and alternatives, the City
Community Development Director recommended Alternative 3: High Density, No Road Diet,
rather than the refined project, as the land use planning and development scenario that best
meets the needs of the City.
V.2 Comparative Analysis of Alternatives
This section of the Findings of Fact provides a comparative analysis of recommended Alternative
3 and the four alternatives evaluated in the SIR in relation to three factors:
• Attainment of the development goals resulting from the TAP Report,'2 and supporting
marketing feasibility study1l3 City adopted Complete Streets Project (Table V.2-1,
Comparison of Specific Plan Elements for Recommended Project and Alternatives)
1. Market demand exists for over 2,000 housing units;
2. Redevelopment and repositioning of existing retail space, which would benefit from
synergies created by new housing; and
3. Low demand for office development in the area
• Ability to meet Diamond Bar Town Center Specific Plan Objectives (Table V.2-2, Ability of
Recommended Project and Alternatives to Meet the Diamond Bar Town Center Specific
Plan Objectives)
• Environmental impacts (Table V.2-3, Comparative Analysis of Impacts for Recommended
Alternative 3 and Alternative Considered)
12 City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
April2021?bidl& . Accessed January 13, 2026.
13 RCLCO Real Estate Consulting. Existing Conditions & Market Demand Analysis: Diamond Bar Town Center for the
Cit of Diamond Bar, California. September 6, 2022.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page V-3
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TABLE V.2-2
ABILITY OF RECOMMENDED ALTERNATIVE 3 AND ALTERNATIVES
TO MEET DIAMOND BAR TOWN CENTER SPECIFIC PLAN OBJECTIVES
Does the Alternative (Alt.)
Accomplish the Project
Objectives?
Recommended
No -Project
Refined
Project Objectives
Alt. 3
Alt.
Project
Alto
Alt. 2
1. Implement the community vision, goals, and policies
Yes
Yes
Yes
Yes
Yes
of the General Plan, which established the Town
Center Mixed Use land use designation to "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, andgather."
2. Make the Town Center a complete neighborhood with
Yes
No >
Yes
Yes
Yes
a sense of place, that takes advantage of its location,
to provide residents and visitors a unique experience.
3. Ensure that the physical design and programming of
Yes
No
Yes
Yes
Yes
the Town Center supports health, wellbeing, and
environmental sustainability, the latter so as to make
progress toward meeting the greenhouse gas
reduction targets of the Diamond Bar Climate Action
Plan by supporting compact, infill, mixed -use
development,
4. Allow for cardite I car -optional living allowing those
Yes
No -
Yes
Yes
Yes
who choose not to use their car on a daily basis or
who choose not to own a car at all to be easily
accommodated, thus furthering progress to the City's
climate action goals
5. Provide great public spaces, and small parks with
Yes
No
Yes
Yes
Yes
regenerative landscapes to support the goal of
environmental sustainabilit
6. Include a mix of uses and urban housing types at a
Yes
Yes
Yes
Yes
Yes
range of affordability levels, so as to implement the
6th Cycle Housing Element (Chapter 9 of the
General Plan) and to fulfill Diamond Bar's
commitment to provide affordable housing
opportunities by rezoning the Town Center Specific
Plan project area to facilitate the development of a
portion of Diamond Bar's Regional Housing Needs
Assessment (RHNA) allocation, including the
production of housing that will be affordable to lower -
income households.
7. Provide flexibility for the future —particularly for retail
Yes
Yes
Yes
Yes
Yes
and commercial space —so as to adapt to changes in
lifestyle and market conditions that are likely to occur
throughout the lifes an of the plan
8. Facilitate the development of the Town Center in
Yes
Yes
Yes
Yes
Yes
phases or increments so as to recognize the multiple
owners in the Plan Area and the expectation that
these owners will likely have different time frames for
redevelopment
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page V-5
TABLE V.2-3
COMPARATIVE ANALYSIS OF IMPACTS FOR RECOMMENDED ALTERNATIVE 3 AND
ALTERNATIVES CONSIDERED
1
Level
of
impact
Comparison
No -Project
Recommended
Alternative
Alternative 1
Alternative 3
(Housing
Refined Project
(Medium
Alternative 2
(High Density,
Element
(High Density
Density with
(Low Density with
Impact
No Road Diet)
Update)
with Road Diet
Road Diet
Road Diet
Aesthetics
Light and Glare
LTS
LTS Similar
LTS Similar
LTS Lesser
LTS Lesser
Air Quality
Air Quality Plan
LTS
LTS (Similar)
LTS (Similar)
LTS (Similar)
LTS (Similar)
Air Quality Standards
SU
SU (Similar)
SU (Lesser)
SU (Lesser)
SU (Lesser)
Sensitive Receptors
SU
SU (Similar)
SU (Similar)
SU (Lesser)
SU (Lesser)
Odors
LTS
LTS Similar
LTS Similar
LTS Similar
LTS Similar
Greenhouse Gas Emissions
Greenhouse Gas Emissions
LTS
LTS Greater
LTS Lesser
LTS Lesser
LTS Lesser
Hydrology and Water Quality
Groundwater
LTS
LTS Greater
LTS Similar
LTS Similar
LTS Similar
Noise
Ambient Noise
LTS
LTS (Similar)
LTS (Similar)
LTS (Similar)
LTS (Similar)
Groundborne Vibration
LTS
LTS Similar
LTS Similar
LTS Similar
LTS Similar
Public Services
Park Facilities
LTS
LTS (Similar)
LTS (Similar)
LTS (Similar)
LTS (Similar)
Other Public Facilities
LTS
LTS Similar
LTS Similar
LTS Similar
LTS Similar
Recreation
Deterioration of Facilities
LTS
LTS (Similar)
LTS (Similar)
LTS (Similar)
LTS (Similar)
Construction of Facilities
LTS
LTS Similar
LTS Similar
LTS Similar
LTS Similar
Transportation
Vehicle Miles Traveled
SU
SU Greater
SU Similar
SU Similar
SU Similar
Utilities and Service Systems
Water or Wastewater Facilities
LTS
LTS (Similar)
LTS (Similar)
LTS (Similar)
LTS (Similar)
Water Supply
LTS
LTS (Similar)
LTS (Similar)
LTS (Similar)
LTS (Similar)
Wastewater Capacity
LTS
LTS Similar
LTS Similar
LTS Similar
LTS Similar
Note: NI = No Impact; LTS = Less than Significant; LTSM = Less than Significant with Mitigation; SU = Significant and
Unavoidable.
Less = Impacts are less than those that would occur with the Alternative 3; Similar = Impacts are similar to those that would
occur with the Alternative 3; Greater = Impacts are greater than those that would occur with the Alternative 3.
.2.1 Recommended Alternative 3: High Density, No Road Diet
Specific Plan Elements: Recommended Alternative 3 was designed to implement General Plan
2040 by supporting its vision and development policies which guide the physical growth of the
Town Center Planning Area, taking into consideration the recommended Specific Plan elements
resulting from the TAP Report,14 and supporting market feasibility study.15 In addition,
14 City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
Apri12021 ?bid Id . Accessed January 13, 2026.
'S RCLCO Real Estate Consulting. Existing Conditions & Market Demand Analysis: Diamond Bar Town Center for the
'it of Diamond Bar, California. September 6, 2022,
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page V-6
Recommended Alternative 3 does not include a road diet, and as such is compatible with the
City's Complete Streets Project.
Alternative 3 achieves the highest number of housing units and hotel rooms, square footage of
retail/commercial space, and square footage of open space within the Planning Area; retains
Diamond Bar Boulevard in a comparable condition to the existing condition; retains sidewalks
adjacent to Diamond Bar Boulevard; and adds Class IV and Class III bicycle lanes (Table V.2-
1), as indicated below:
• Up to 21055 multi -family housing units
• 200 hotel rooms,
• 446,000 square feet (sf) of commercial leasable space
• 40,000 sf of open space
• Six lanes of Diamond Bar Boulevard are retained within the Specific Plan Area, with 11-
foot-wide lane widths, and 10400t-wide turn pockets
• Does not accommodate parking on Diamond Bar Boulevard
• Existing & to 15400t-wide sidewalks adjacent to Diamond Bar Blvd are retained
• Class IV Bicycle Lanes on Diamond Bar Boulevard, Golden Springs Drive, Grand Avenue,
and Prospectors Road, and Class III on Sunset Crossing Road
Recommended Alternative 3 achieves and exceeds the 2,000 dwelling units recommended by
the TAP Report,'s adds 103 hotel room, adds 40,000 sf of open space, and retains 446,000 sf
of retail/commercial space. Recommended Alternative 3 also preserves six lanes on Diamond
Bar Boulevard within the Specific Plan area and, as such, is compatible with the City's Complete
Streets Project.
Effectiveness in Meeting Project Objectives: Recommended Alternative 3, meets the eight
objectives established for the Diamond Bar Town Center Specific Plan (see Table V.2-2).
Alternative 3 Environmental Impacts: Recommended Alternative 3 results in less than
significant impacts to light and glare, consistency with air quality plans, construction emissions,
)dors, greenhouse gas emissions, depletion of groundwater, ambient noise, groundborne
vibration, park facilities, other public facilities, deterioration of existing recreation facilities, or the
need to construct new recreation facilities, water or wastewater facilities, water supply or
wastewater capacity (Table V.2-3). Recommended Alternative 3 results in significant and
unavoidable impacts related to emissions of criteria pollutants, ROG and PM2.5, during operation
and exposure of sensitive receptors to criteria air pollutants. Although Traffic Demand
Management measures would be employed with Recommended Alternative 3, per capita vehicle
miles travelled would be expected to increase in the Specific Plan area due to the addition of
2,055 dwelling units and 200 hotel rooms over the existing condition, and 705 more dwelling units
than General Plan 2040, as updated by the 2021-2029 Housing Element Update (Table V.2-3).
Recommended Alternative 3 requires implementation of seven Air Quality measures identified in
the Certified General Plan EIR: MM-AQ-1, MM-AQ-2, MM-AQ-3, MM-AQ-4, MM-AQ-5, MM-AQ-
6, and MM-AQ-7. In addition, Recommended Alternative 3 requires implementation of MM-
TRANS-1. Alternative 3 is the recommended alternative because it provides a balance of land
's City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
Apri12021?bidl& . Accessed January 13, 2026.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page V-7
uses that would achieve the highest number of housing units and hotel rooms, square footage of
retail/commercial space, and square footage of open space within the Planning Area; retains
Diamond Bar Boulevard in a comparable condition to the existing condition; retains sidewalks
adjacent to Diamond Bar Boulevard; and adds Class IV and Class III bicycle lanes. Alternative 3
is able to accommodate the bicycle lane improvements contemplated by the Complete Streets
Project. In addition, turn lane width and turn pocket width are based on the width with the
Complete Streets Project in place for the approved General Plan 2040 and proposed Alternative
3.
V.2.2 No -Project Alternative (Housing Element Update)
Specific Plan Elements: Under the No -Project Alternative, the Specific Plan Area would be
subject to the General Plan 2040, as updated by the 2021-2029 Housing Element and Land
Use Planning Element policies, regulations, development standards, and land use designations
that apply to the Town Center Mixed Use, land use designation. Under the No -Project
Alternative (Housing Element Update), the maximum FAR would be 1.5 for the entire Town
Center. The No -Project Alternative would allow for development in the Town Center Focus Area
consistent with the approved Town Center development density from the Housing Element
Update:
• Up to 1,350 multi -family dwelling units
• 97 hotel rooms
• 510.000 sf of commercial leasable space
• 0 sf of open space
• Six lanes of Diamond Bar Boulevard are retained within the Specific Plan Area, with 11-
to 14.5400t-wide lane widths, and 8.5- to 15400t-wide turn pockets
• Does not accommodate parking on Diamond Bar Boulevard
• Existing 8- to 15400t-wide sidewalks adjacent to Diamond Bar Blvd are retained
• Class IV Bicycle Lanes on Diamond Bar Boulevard, Golden Springs Drive, Grand Avenue,
and Prospectors Road and Class III on Sunset Crossing Road
When compared to Recommended Alternative 3, the No -Project Alternative results in 705 fewer
dwelling units, 103 fewer hotel rooms, no open space, and 64,000 more sf of retail/commercial
space, thus falling far short of the recommendations of the TAP Report." It provides no open
space. As with Recommended Alternative 3, the No -Project Alternative preserves six lanes on
Diamond Bar Boulevard within the Specific Plan area and, as such, is compatible with the City's
Complete Streets Project.
Effectiveness in Meeting Project Objectives: Under the No -Project Alternative, four of the eight
objectives —Objectives 1, 6, 7, and 8—would be met (see Table V.2-2). Although the No -Project
Alternative meets Objective 1 by providing 1,350 dwelling units, this is only 68 percent of the
market demand for 2,000 dwelling units identified by the TAP Report.'' The No -Project Alternative
fails to meet Objectives 2, 31 4, and 5, because it does not include components that would create
a sense of place, such as open space, and would not further the City's progress toward its climate
�7 City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
Apri12021?bidld= .Accessed January 13, 2026.
1e City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
Apri12021?bidld= . Accessed January 13, 2026,
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page V-8
action goals (Table V.2-2). In addition, the No -Project Alternative would not meet the market
demand of over 2,000 housing units determined by the market feasibility study" (Table V.2-2).
Comparative Impacts of the No -Project Alternative: As with Recommended Alternative 3, the
No -Project Alternative results in less than significant impacts to light and glare, consistency with
air quality plans, odors, greenhouse gas emissions, depletion of groundwater, ambient noise,
groundborne vibration, park facilities, other public facilities, deterioration of existing recreation
facilities, or the need to construct new recreation facilities, water or wastewater facilities, water
supply or wastewater capacity (Table V.2-3). The No -Project Alternative results in significant and
unavoidable impacts related to emissions of criteria pollutants, NOx, PM2.5, and PMjo, during
construction and exposure of sensitive receptors to criteria air pollutants due to the proximity and
intensity of construction activities. The No -Project Alternative results in significant and
unavoidable impacts related to exposure of sensitive receptors to criteria air pollutants due to the
proximity and intensity of construction activities. In addition, like Recommended Alternative 3, the
No -Project Alternative would result in significant and unavoidable impacts due to the 1,350
additional dwelling units, 97 hotels rooms, and retention of 510,000 sf of retail/commercial space.
Without increasing local housing, the No -Project Alternative would exacerbate the per capita VMT
by focusing on destination trips from housing and office space beyond the limits of the Specific
Plan Area. Unlike Recommended Alternative 3, the No -Project Alternative does not require Traffic
Demand Management measures that would be employed with Recommended Alternative 3, thus
further contributing to increase per capita VMT (Table V.2-3).
The No -Project Alternative does not resolve the significant and unavoidable impacts that would
occur with the recommended Alternative 3.
As with Recommended Alternative 3, the No-ProjectAnernative requires implementation of seven
Air Quality Measures identified in the Certified General Plan EIR: MM-AQ-1, MM-AQ-2, MM-AQ-
3, MM-AQ-4, MM-AQ-5, MM-AQ-6, and MM-AQ-7. MM-TRANS-1 was not included in the Certified
General Plan EIR.
The No -Project Alternative is, thus, deemed to be infeasible and is not recommended as it would
only meet four of the eight project objectives and would not avoid significant environmental
impacts. In addition, the No -Project Alternative would exacerbate the per capita VMT and would
not provide a balance of land uses that would achieve the highest number of housing units and
square footage of open space within the Planning Area.
4
2.3 Refined Project, High Density with Road Diet
Specific Plan Elements: As with Recommended Alternative 3, the Refined Project was designed
to implement General Plan 2040 by supporting its vision and development policies which guide
the physical growth of the Town Center Planning Area, taking into consideration the
recommended Specific Plan elements resulting from the TAP Report,20 and supporting market
19 RCLCO Real Estate Consulting. Existing Conditions &Market Demand Analysis: Diamond Bar Town Center for the
Cit of Diamond Bar, California. September 6, 2022.
20 City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
April2021?bidld= . Accessed January 13, 2026.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page V-9
feasibility study.2',22 Unlike Recommended Alternative 3, the refined project includes a road diet
and, as such, is incompatible with the City's Complete Streets Project.
As with Recommended Alternative 3, the refined project achieves the highest number of
housing units and hotel rooms, square footage of retail/commercial space, and the same square
footage of open space within the Planning Area and adds bicycle lanes (Table V.2-1):
• Up to 2,055 multi -family housing units
• 200 hotel rooms
• 446,000 sf of commercial leasable space
• 40,000 sf of open space
• Four of six lanes of Diamond Bar Boulevard are retained within the Specific Plan Area,
with 11-14.54eet-wide lane widths, and 5- to 154eet-wide turn pockets
• Accommodates parking on Diamond Bar Boulevard
• Existing 84eet wide sidewalks adjacent to Diamond Bar Boulevard are retained
• Class IV Bicycle Lanes on Diamond Bar Bolulevard, Golden Springs Drive, Grand
Avenue, and Prospectors Road and Class III bicycle lane on Sunset Crossing Road
The proposed refinements to Diamond Bar Boulevard within the Specific Plan Area are
incompatible with the City's Complete Streets Project.
Effectiveness in Meeting Project Objectives: As with Recommended Alternative 3, the refined
project meets the eight objectives established for the Diamond Bar Town Center Specific Plan
(see Table V.2-1).
Comparative Impacts of the Refined Project Alternative: As with Recommended Alternative
3, the refined project results in less than significant impacts to light and glare, consistency with air
quality plans, odors, greenhouse gas emissions, depletion of groundwater, ambient noise,
groundborne vibration, park facilities, other public facilities, deterioration of existing recreation
facilities, or the need to construct new recreation facilities, water or wastewater facilities, water
supply or wastewater capacity (Table V.2-3). As with Recommended Alternative 3, the refined
project results in significant and unavoidable impacts related to emissions of criteria pollutants,
ROG, and PM2.5, during operation and exposure of sensitive receptors to criteria air pollutants
(Table V.2-3). As with Recommended Alternative 3, the refined project requires Traffic Demand
Management measures to be applied; however, per capita VMT would be expected to increase
in the Specific Plan area due to the addition of 2,055 dwelling units and 200 hotel rooms over the
existing conditions, and 705 more dwelling units than General Plan 2040, as updated by the 2021-
2029 Housing Element Update (Table V.2-3).
The refined project does not resolve the significant and unavoidable impacts that would occur
with the recommended Alternative 3.
As with Recommended Alternative 3, the refined project requires implementation of seven Air
Quality measures identified in the Certified General Plan EIR: MM-AQ-1, MM-AQ-2, MM-AQ-3,
21 City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
Apri12021?bidld= .Accessed January 13, 2026.
z2 RCLCO Real Estate Consulting. Existing Conditions & Market Demand Analysis: Diamond Bar Town Center for the
'it of Diamond Bar, California. September 6, 2022,
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page V-10
MM-AQ-4, MM-AQ-5, MM-AQ-6, and MM-AQ-7. In addition, as with Recommended Alternative
3, the refined project requires implementation of MM-TRANS-1.
The refined project is, thus, deemed to be infeasible and is not recommended as it would be
incompatible with the Complete Streets Project (see Table V.2-1). The incompatibility of the road
diet element of the refined project with the adopted Complete Streets Project was determined by
the Director of Community Development to not be in the best interest of the City.
V.2.4 Alternative 1 (Medium Density with Road Diet)
Specific Plan Elements: As with Recommended Alternative 3, Alternative 1 was designed to
implement General Plan 2040 by supporting its vision and development policies which guide
the physical growth of the Planning Area, taking into consideration the recommended Specific
Plan elements resulting from the TAP Report123 and supporting market feasibility stud y.24 Unlike
Recommended Alternative 3, Alternative 1 includes a road diet and, as such, is incompatible
with the City's Complete Streets Project.
As with Recommended Alternative 3, Alternative 1 provides dwelling units and hotel rooms,
retail/commercial space, and open space within the Diamond Bar Specific Plan Area and adds
bicycle lanes (Table V.2-1):
• Up to 1,677 multi -family housing units
• 175 hotel rooms
• 426,000 sf of commercial leasable space
• 40,000 sf of open space
• Four of six lanes of Diamond Bar Boulevard are retained within the Specific Plan Area,
with 11- to 14.5400t-wide lane widths, and 5- to 15400t-wide turn pockets
• Accommodates parking on Diamond Bar Boulevard
• Existing 8400t-wide sidewalks adjacent to Diamond Bar Boulevard are retained
• Class IV Bicycle Lanes on Diamond Bar Blvd, Golden Springs Drive, Grand Avenue, and
Prospectors Road and Class III bicycle lane on Sunset Crossing Road
Alternative 1 calls for less development than Recommended Alternative 3. Specifically, there
would be 378 fewer dwelling units, 25 fewer hotel rooms, and 20,000 sf less retail/commercial
space. As with Recommended Alternative 3, Alternative 1 calls for the development of 40,000
sf of open space. Unlike Recommended Alternative 3, Alternative 1 includes a road diet
reducing Diamond Bar Boulevard from six lanes within the Planning Area to four lanes.
The proposed refinements to Diamond Bar Boulevard (reduction from six lanes to four lanes)
within the Specific Plan Area are incompatible with the City's Complete Streets Project.
Effectiveness in Meeting Project Objectives: As with Recommended Alternative 3, Alternative
1 meets the eight objectives established for the Diamond Bar Town Center Specific Plan; however,
Objectives 6 and 7 would only be partially met due to the reductions in dwelling units and
Zs City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
April2021?bidld= . Accessed January 13, 2026.
24 RCLCO Real Estate Consulting, Existing Conditions & Market Demand Analysis: Diamond Bar Town Center for the
Cit of Diamond Bar, California. September 6, 2022,
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page V 11
retail/commercial space (see Table V.2-1). Although Alternative 1 meets Objective 1 by providing
1,677 dwelling units, this is only 84 percent of the market demand for 2,000 dwelling units
identified by the TAP Report.21
Comparative Impacts of Alternative 1: As with Recommended Alternative 3, Alternative 1
results in less than significant impacts to light and glare, consistency with air quality plans, odors,
greenhouse gas emissions, depletion of groundwater, ambient noise, groundborne vibration, park
facilities, other public facilities, deterioration of existing recreation facilities, or the need to
construct new recreation facilities, water or wastewater facilities, water supply or wastewater
capacity (Table V.2-3). As with Recommended Alternative 3, Alternative 1 results in significant and
unavoidable impacts related to emissions of criteria pollutants, ROG and PM2.5, during operation
and exposure of sensitive receptors to criteria air pollutants (Table V.2-3). As with Recommended
Alternative 3, Alternative 1 requires Traffic Demand Management Measures to be applied;
however, per capita VMT would be expected to increase in the Specific Plan area due to the
addition of 1,677 dwelling units and 175 hotel rooms over the existing condition, and 327 more
dwelling units than General Plan 2040, as updated by the 2021-2029 Housing Element Update
(Table V.2-3).
Alternative 1 does not resolve the significant and unavoidable impacts that would occur with the
recommended Alternative 3.
As with Recommended Alternative 3, Alternative 1 requires the implementation of seven Air
Quality measures identified in the Certified General Plan EIR: MM-AQ-1, MWAQ-2, MWAQ-3,
MM-AQ4, MWAQ-5, MWAQ-6, and MWAQ-7. In addition, as with Recommended Alternative 3,
Alternative 1 requires implementation of MM-TRANS-1.
Alternative 1 is, thus, deemed to be infeasible and is not recommended as it would not meet all
of the project objectives as fully as Alternative 31 would not avoid the significant impacts that would
occur under Alternative 3, and would be incompatible with the Complete Streets Project (see
Table V.2-1). The incompatibility of the road diet element of Alternative 1 with the adopted
Complete Streets Project was determined by the Director of Community Development to not be
in the best interest of the City. In addition, Alternative 1 would not fully provide a balance of land
uses that would achieve the highest number of housing units and commercial space within the
Planning Area as it would provide fewer housing units and commercial space than Alternative 3.
V.2.5 Alternative 2: Low Density with Road Diet
Specific Plan Elements: As with Recommended Alternative 3, Alternative 2 was designed to
implement General Plan 2040 by supporting its vision and development policies which guide
the physical growth of the Town Center Planning Area, taking into consideration the
recommended Specific Plan elements resulting from the TAP Report,26 and supporting market
25 City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
Apri12021?bidld= .Accessed January 13, 2026.
2s City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
Apri12021?bidld= . Accessed January 13, 2026.
Diamond
Bar
Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page U 12
feasibility study.27 Unlike Recommended Alternative 3, Alternative 2 includes a road diet and, as
such, is incompatible with the City's Complete Streets Project.
As with Recommended Alternative 3, Alternative 2 provides dwelling units and hotel rooms,
retail/commercial space, and open space within the Planning Area and adds bicycle lanes
(Table V.2-1):
• Up to 1,350 multi -family housing units
• 150 hotel rooms
• 4111000 sf of commercial leasable space
• 40,000 sf of open space
• Four of six lanes of Diamond Bar Boulevard are retained within the Planning Area, with
11- to 14.5400t-wide lane widths, and 5- to 15400t-wide turn pockets
• Accommodates parking on Diamond Bar Boulevard
• Existing 8-foot-wide sidewalks adjacent to Diamond Bar Boulevard are retained
• Class IV Bicycle Lanes on Diamond Bar Blvd, Golden Springs Drive, Grand Avenue, and
Prospectors Road and Class III bicycle lane on Sunset Crossing Road
Alternative 2 calls for even less development than recommended Alternative 3. Specifically,
there would be 705 fewer housing units, 50 fewer hotel rooms, and 35,000 sf less
retail/commercial space. As with Recommended Alternative 3, Alternative 2 calls for
development of 40,000 sf of open space. Unlike Recommended Alternative 3, Alternative 1
includes a road diet reducing Diamond Bar Boulevard from six lanes within the Planning Area
to four lanes.
The proposed refinements to Diamond Bar Boulevard (reduction from six lanes to four lanes)
within the Specific Plan Area are incompatible with the City's Complete Streets Project.
Effectiveness in Meeting Project Objectives: As with Recommended Alternative 3, Alternative
2 meets the eight objectives established for the Diamond Bar Town Center Specific Plan;
(however, Objectives 6 and 7 would only be partially met due to the reductions in dwelling units
and retail/commercial space) (see Table V.2-1). Although Alternative 2 meets Objective 1 by
providing 1,350 dwelling units, this is only 68 percent of the market demand for 2,000 dwelling
units identified by the TAP Report.28
Comparative Impacts of Alternative 2: As with Recommended Alternative 3, Alternative 2
results in less than significant impacts to light and glare, consistency with air quality plans, odors,
greenhouse gas emissions, depletion of groundwater, ambient noise, groundborne vibration, park
facilities, other public facilities, deterioration of existing recreation facilities, or the need to
construct new recreation facilities, water or wastewater facilities, water supply or wastewater
capacity (Table V.2-3). As with Recommended Alternative 3, Alternative 2 results in significant and
unavoidable impacts related to emissions of criteria pollutants, ROG and PM2.5, during operation
and exposure of sensitive receptors to criteria air pollutants (Table V.2-3). As with Recommended
Alternative 3, Alternative 2 requires Traffic Demand Management Measures to be applied;
27 RCLCO Real Estate Consulting. Existing Conditions & Markef Demand Analysis: Diamond Bar Town Center for the
Cit of Diamond Bar, California. September 6, 2022.
2e City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenter/View/8250/Diamond-Bar-Town-Center-Report-
Apri12021?bidld= . Accessed January 13, 2026.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page V-13
however, per capita VMT would be expected to increase in the Specific Plan area due to the
addition of 1,350 dwelling units and 150 hotel rooms over the existing conditions (Table V.2-3).
Dwelling units would be the same as General Plan 2040, as updated by the 2021-2029 Housing
Element Update (Table V.2-3).
As with Recommended Alternative 3, Alternative 2 requires the implementation of seven Air
Quality measures identified in the Certified General Plan EIR: MM-AQ-1, MM-AQ-2, MM-AQ-3,
JI WAQ-4, MM-AQ-5, MM-AQ-6, and MM-AQ-7. In addition, as with Recommended Alternative 3,
Alternative 2 requires implementation of MM-TRANS-1.
The SIR identified Alternative 2, with its lesser impacts under four impact categories, and reduced
development scenario and construction footprint, as the Environmentally Superior Alternative,
However, Alternative 2 was found to be inconsistent with the City's goals and policies because it
would not fully meet the eight objectives established for the Diamond Bar Town Center Specific
Plan due to the reduced development scenario. As such, the Environmentally Superior Alternative
was deemed infeasible and not recommended to the Planning Commission or City Council for
adoption (see Section V.3, Environmentally Superior Alternative).
V.3 Environmentally Superior Alternative
Section 15126.E of the CEQA Guidelines requires the identification of an environmentally
superior alternative among the alternatives analyzed. Section 15126.6(e) of the CEQA
Guidelines requires the evaluation of a "No -Project Alternative" and its potential environmental
impacts. Where the proposed project is a land use or regulatory plan, the "No -Project
Alternative" is a continuation of the existing plan or policy into the future (CEQA Guidelines
Section 15126.6(b)(3)(A)). As a result, "the projected impacts of the proposed plan ... would be
compared to the impacts that would occur under the existing plan" (Section 15126.6(b)(3)(A) of
the CEQA Guidelines). The "environmentally superior alternative" in CEQA refers to the
alternative that would result in the fewest or least severe environmental impacts among all
alternatives evaluated in an EIR. If the alternative with the least environmental impact is the No -
Project Alternative, then the EIR must also identify the next most environmentally superior
alternative (CEQA Guidelines Section 15126.6(e)(2)).
As shown in Table V.2-3, above, Alternatives 1 (Medium Density with Road Diet) and 2 (Low
Density with Road Diet) would have impacts to four issue areas that are less than those of
Recommended Alternative 3 (High Density, No Road Diet) (aesthetics/light and glare, air quality
standards, and GHG emissions). The refined project would have impacts to two issue areas
that are less than those of Recommended Alternative 3 (air quality standards and GHG
emissions). By comparison, the No -Project Alternative would result in similar or greater impacts
for all impact areas compared to Recommended Alternative 3.
Both Alternatives 1 and 2 would result in lesser impacts to light and glare as compared to
Recommended Alternative 3. However, by virtue of Alternative 2's reduced development
scenario and construction footprint (705 less housing units, 53 less hotel rooms, and 55,000 sf
less of retail/commercial development), Alternative 2 would result in a lower level of sources of
light and glare. Both Alternatives 1 and 2 would result in lesser impacts to emissions of criteria
pollutants and the exposure of sensitive receptors to the emissions of criteria pollutants when
compared to Recommended Alternative 3; however, by virtue of the Alternative 2 reduced
development scenario and construction footprint, it would result in lower level of sources of
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 202E Page V-14
emissions of criteria pollutants. Both Alternatives 1 and 2 would result in lesser impacts to GHG
emissions when compared to Recommended Alternative 3.
Alternative 2, with its lesser impacts under the four impact categories, and reduced development
scenario and construction footprint, is the Environmentally Superior Alternative, However,
Alternative 2 was found to be inconsistent with City's goals and policies as they relate to a
reduction of dwelling units to 68 percent of the market demand established in the TAP Report,29
and the corresponding reduction in consumers to support retail/commercial development.
Similarly, the incompatibility of the Road Diet element of Alternative 2 with the adopted Complete
Streets Project was found to be inconsistent with the City's goals and policies. While Alternative
2 would meet the eight objectives established for the Diamond Bar Town Center Specific Plan,
Objectives 6 and 7 would only be partially met due to the reduced development scenario. And
while lowering emissions during construction, Alternative 2 shares the same significant and
unavoidable impacts that would result from Recommended Alternative 3. Further, although
Alternative 2 meets Objective 1 by providing 1,350 dwelling units, this reduced development
scenario is only 68 percent of the market demand for 2,000 dwelling units identified by the TAP
Report and would be economically infeasible to meet the City's requirements. Therefore, while
Alternative 2, with its lesser impacts with respect to the four impact categories and reduced
development scenario and construction footprint, is the Environmentally Superior Alternative, it
was thus rejected as infeasible.
29 City of Diamond Bar. April 2021. Los Angeles Diamond Bar Town Center: Technical Assistance Panel Report.
Available at: https://www.diamondbarca.gov/DocumentCenterNiew/8250/Diamond-Bar-Town-Center-Report-
Apri12021?bidld= .Accessed January 13, 2026.
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VI FINDINGS REGARDING MITIGATION
MONITORING AND REPORTING PROGRAM
According to Section 21081.E of the Public Resources Code, and pursuant to Sections 15091 and
15097 of the State CEQA Guidelines, CEQA requires that when a public agency is making the
findings required by Section 21081 and Section 15091, the public agency shall adopt a reporting
or monitoring program for the changes made to the project or conditions of project approval,
adopted to mitigate or avoid significant effects on the environment.
The City of Diamond Bar hereby finds that the Mitigation Monitoring and Reporting Program for
the Recommended Alternative 3 meets the requirements of Section 21081.6 of the Public
Resources Code and Sections 15091 and 15097 of the State CEQA Guidelines by providing a
monitoring program designed to ensure compliance during project implementation with mitigation
measures adopted by the City.
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VII FINDINGS REGARDING LOCATION AND
CUSTODIAN OF DOCUMENTS
Section 15091(e) of the State CEQA Guidelines requires a public agency specify the location and
custodian of the documents or other materials that constitute the record of proceedings upon
which the decision is based.
The documents and other materials that constitute the Record of Proceedings on which the City
of Diamond Bar's Findings of Fact are based are located at:
City of Diamond Bar
Community Development Department/Planning Division
21810 Copley Dr.
Diamond Bar, CA 91765
Phone: (909) 839-7030
Email: glee(adiamondbarca.gov
The Record of Proceedings, including copies of the SIR and all documents incorporated by
reference in the SIR, are available for review between the hours of 7:30 a.m. and 5:30 p.m.
Monday through Thursday, and 7:30 a.m. to 4:30 p.m. on Friday.
The custodian of these documents is the City of Diamond Bar. This information is provided in
compliance with Public Resources Code Section 21081.6(a)(2).
For purposes of CEQA and these Findings, the Record of Proceedings for the Project consists of
the following documents and other evidence, at a minimum:
• The NOP, NOA, and all other public notices issued by the City of Diamond Bar in
conjunction with the Project;
• The Final SIR;
• The Draft SIR;
• All written comments submitted by agencies or members of the public during the public
review comment period on the Draft SIR;
• All responses to written comments submitted by agencies or members of the public during
the public review comment period on the Draft SIR;
• All written and verbal public testimony presented during a noticed public hearing for the
project;
• The reports and technical memoranda included or referenced in the Response to
Comments;
• All documents, studies, or other materials incorporated by reference in the Draft SIR and
Final SIR;
• The Resolutions adopted by the City of Diamond Bar in connection with the project, and
all documents incorporated by reference therein, including comments received after the
close of the comment period and responses thereto;
• Matters of common knowledge to the City of Diamond Bar, including but not limited to
federal, state, and local laws and regulations;
• Any documents expressly cited in these Findings; and,
• Any other relevant materials required to be in the record of proceedings by Public
Resources Code Section 21167.6(e),
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page VII-1
VIII CERTIFICATION REGARDING INDEPENDENT
JUDGMENT
The City of Diamond Bar reviewed the Draft SIR, its supporting technical appendices, and
required changes to those documents prior to their circulation for public review. The Draft SIR
circulated for public review reflected the independent judgment of the City of Diamond Bar. The
Final SIR similarly has been subject to review and revision by the City of Diamond Bar City
Council, Planning Commission, and Community Development Department. Pursuant to Section
21082.1(c) of the Public Resources Code and Section 15090(a)of the State CEQA Guidelines,
the City of Diamond Bar certifies that the Final SIR was presented to the City Council and that the
City Council has independently reviewed and analyzed the Final SIR prior to making a decision
on the project. The Final SIR reflects the City Council Is independent judgment and analysis.
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page VIII-1
IX STATE CEQA GUIDELINES SECTIONS 15091,
15092, AND 15093 FINDINGS
The City has prepared a Final SIR. The Final SIR includes all comments received during the
public comment period and responses to public comments. A copy of the response to comments
was provided to the party making the comment prior to the consideration of the Final SIR for
certification and prior to consideration of the Diamond Bar Town Center Specific Plan for
certification. The City made the Final SIR available for review by the public for a period 10 days
prior to consideration for certification, and provided the public with the opportunity to comment
at the Public Hearing held by the Planning Commission and a Public Hearing held by the City
Council to consider certification of the Final SIR and consider approval of the Diamond Bar
Town Center Specific Plan as described in Alternative 3 (High Density, No Road Diet). Based
on the whole record, the Community Development Director has recommended Alternative 3
(High Density, No Road Diet) to the Planning Commission and City Council for approval. This
section includes documentation of compliance with the required FOF/SOC to support the
consideration of the Final SIR for approval and consideration of Recommended Alternative 3
(High Density, No Road Diet) by the City Council.
IX.1 State CEQA Guidelines Section 15091 Findings
The City has made the required findings with respect to the significant impacts on the environment
resulting from the City of Diamond Bar Town Center Specific Plan Recommended Alternative 3
(High Density, No Road Diet) pursuant to Section 15091 of the State CEQA Guidelines.
(a) Required Findings for Significant Environmental Effects Supported by Substantial
Evidence
(1) Changes or alterations have been required in, or incorporated into, the project
which avoid or substantially lessen the significant environmental effect as identified
in the Final SIR. The Final SIR and FOF/SOC document the analysis that was
undertaken with respect to each environmental issue area carried forward for
detailed evaluation in the Final SIR:
a. Significant Unavoidable Adverse Impacts That Cannot Be Mitigated to a
Level of Insignificance (SIR Section 4.6, Impact Analysis of Alternatives,
and FOF/SOC Section IV, Significant Unavoidable Adverse Impacts That
Cannot Be Mitigated to ,Below the Level of Significance).
(2) Such changes or alterations are within the responsibility and jurisdiction of another
public agency and not the agency making the finding. Such changes have been
adopted by such other agency or can and should be adopted by such other agency.
a. The City has determined that the changes or alterations to the land use
development scenario adopted in the Diamond Bar General Plan 2040
(General Plan 2040),' as updated by the 2021-2029 Housing Element
Update and Land Use Planning Update that are embodied in
Recommended Alternative 3 (High Density, No Road Diet) are solely in
' City of Diamond Bar. 2019. Diamond Bar General Plan 2040. https://www.diamondbarca.gov/961/General-Plan-
2040
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page IX-1
the responsibility of the City. The City has identified the California
Department of Transportation (Caltrans) District 7, Regional Water Quality
Control Board — Los Angeles Region, South Coast Air Quality Management
District, and Southern California Association of Governments as other
decision -making bodies that may rely on the Final SIR in the consideration
and issuance of subsequent projects undertaken pursuant to the Final SIR
("Intended Uses of This SIR" in Section 2.2, Purpose and Objective of the
Refined Project, of the Final SIR). The City provided the Draft SIR to
Caltrans District 7, Regional Water Quality Control Board — Los Angeles
Region, South Coast Air Quality Management District, and Southern
California Association of Governments for review and comment.
(3) Specific economic, legal, social, technological, or other considerations, including
provision of employment opportunities for highly trained workers, make infeasible
the mitigation measures or project alternatives identified in the Final SIR.
a. The City has carried forward the seven applicable mitigation measures
from the certified Diamond Bar Comprehensive General Plan Update and
Climate Action Plan Draft Environmental Impact Report2 and added one
additional mitigation measure for transportation (FOF/SOC Section IV,
Significant Unavoidable Adverse Impacts That Cannot Be Mitigated to
Below the Level of Significance).
IX.2 State CEQA Guidelines Section 15092 Findings
The Community Development Director has determined that based on the whole of the record,
the City Planning Commission and City Council have concurred that the City has:
(a) Eliminated or substantially lessened all significant effects on the environment where
feasible as shown in the Section 15091 Findings, and
(b) Determined any remaining significant effects on the environment found to be unavoidable
under Section 15091 are acceptable due to findings under Section 15093 (FOC/SOC,
Section X, Section 15093 Findings: Statement of Overriding Considerations).
2 City of Diamond Bar. 2019. Diamond Bar Comprehensive General Plan Update and Climate Action Plan Draft
Environmental Impact Report, https://ceganet.opr.ca.gov/2018051066/2
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X STATEMENT OF OVERRIDING CONSIDERATIONS
CEQA and its implementing regulations permit a public agency to approve a project
notwithstanding the existence of significant and unavoidable environmental effects, provided that
the agency makes a written statement identifying the specific benefits of the project that the
agency has determined outweigh those unavoidable effects, and that this determination is
supported by substantial evidence in the record. Specifically, CEQA Guidelines Section 15093
provides as follows:
(a) CEQA requires the decision -making agency to balance, as applicable, the
economic, legal, social, technological, or other benefits, including region -wide or
statewide environmental benefits, of a proposed project against its unavoidable
environmental risks when determining whether to approve the project. If the
specific economic, legal, social, technological, or other benefits, including region -
wide or statewide environmental benefits, of a proposal project outweigh the
unavoidable adverse environmental effects, the adverse environmental effects
may be considered "acceptable."
(b) When the lead agency approves a project which will result in the occurrence of
significant effects which are identified in the final EIR but are not avoided or
substantially lessened, the agency shall state in writing the specific reasons to
support its action based on the final EIR and/or other information in the record. The
statement of overriding considerations shall be supported by substantial evidence
in the record.
(c) If an agency makes a statement of overriding considerations, the statement should
be included in the record of the project approval and should be mentioned in the
notice of determination. This statement does not substitute for, and shall be in
addition to, findings required pursuant to Section 15091.
The SIR concluded that the implementation of Alternative 3 (the "Project") would result in
significant and unavoidable air quality and transportation impacts. Specifically, after imposition of
mitigation measures MM-AQ-1, MM-AQ-2, MM-AQ-3, MM-AQ4, MM-AQ-5, MM-AQ-6, and MM-
AQ-7, the SIR concluded that operation of Alternative 3 would result in significant and unavoidable
impacts based on a cumulatively considerable net increase of ROGs and PM2.5, and with respect
to exposure of sensitive receptors to substantial pollutant concentrations of ROGs and PM2.5.
Further, after imposition of mitigation measure MM-TRANS-1, the SIR concluded that the Project
would result in a significant and unavoidable impact based on project -generated VMT per -service
population.
The Project, however, provides the following benefits:
A. The Specific Plan Would Further Implement the City's Housing Element
Commitments to Meet Regional Housing Needs
The City is required to accommodate its share of regional housing needs as determined by the
Regional Housing Needs Assessment ("RHNA"). On March 4, 2021, the Southern California
Association of Governments ("SCAG") adopted the 6," Cycle RHNA, 2021-2029, which assigned
2,521 dwelling units to the City. That allocation is further broken down across income categories
as follows: 844 extremely low and very low, 434 low, 437 moderate, and 806 above -moderate
Diamond Bar Town Center Specific Plan Findings of Fact and Statement of Overriding Considerations
February 25, 2026 Page X-1
units. In order to plan for this number of units, the City's Housing Element commits the City to
rezone three mixed use focus areas at a density of up to 30 units per acre, including the Town
Center, The City adopted a Housing Element Site Overlay to achieve this minimum density within
the Town Center.
The Specific Plan would further implement the Housing Element's commitments and help the City
to achieve its RHNA allocation by providing development incentives that may exceed those
otherwise available under the City's Development Code (Section 22.18.010) or the State Density
Bonus Law (Government Code Sections 65915-65918) for the production of housing units within
the Town Center. The Specific Plan includes an Inclusionary Incentive Program that would
increase the base density for each "Inclusionary Point" earned by a developer. These points would
be earned by providing, among other things, affordable housing units. (Specific Plan, § 5.3, Table
5-2, Table 5-3.) The goal of this program is to encourage the production of affordable housing in
the Town Center to help the City accommodate its affordable housing RHNA allocation, and,
ultimately, to expand rental and homeownership opportunities for young households, residents
who wish to downsize and remain in Diamond Bar, and members of the workforce for whom
housing costs in Diamond Bar are out of reach.
B. The Specific Plan Is Projected to Generate a Positive Fiscal Impact to the City's
General Fund
In 2022, RCLCO prepared a fiscal impact analysis to evaluate potential development scenarios
for the Town Center. (RCLCO Fiscal Impact Analysis Diamond Bar Town Center, November 18,
2022.) The fiscal impact analysis projected that a development program of approximately 2,055
residential units and approximately 446,000 square feet of commercial space would generate a
stabilized positive annual net fiscal impact of approximately $1.96 million to the City's General
Fund. (p. 5.) The existing use of the site, at the time that the fiscal impact analysis was prepared,
was approximately $1.05 million in annual net fiscal impact. (p. 5.)
The existing Town Center area, which comprises primarily aging automobile -oriented retail
(approximately 456,000 square feet) and a 97-room motel, currently generates limited property
tax revenue (approximately $142,100 annually) and sales tax revenue (approximately $672,800
annually) to the City. (p. 6.) The Specific Plan would transform this underutilized commercial area
into a vibrant mixed -use development. The Specific Plan, which would allow for up to 2,055
residential units and approximately 446,000 square feet of commercial space, closely matches
the residential and commercial components analyzed in the fiscal study. (pp. 4, 6.) And, as a
result, according to the fiscal impact analysis, the Specific Plan could generate approximately
$900,000 more annually as compared to the existing use. (p. 5.)
The increased fiscal benefits would result primarily from new property tax revenues (projected at
approximately $1.24 million annually) and sales tax revenues (projected at approximately $1.11
million annually), as well as transient occupancy tax (projected at approximately $520,500
annually for 97 hotel rooms. (p. 6.) The Specific Plan, however, allows for up to 200 hotel rooms
compared to the 97 hotel rooms analyzed in the fiscal study, which would generate additional
transient occupancy tax revenues beyond those projected in the analysis. (pp. 41 16.) While the
Specific Plan would result in increased demand for City services due to the additional residential
population and commercial activity, the incremental General Fund expenditures required to serve
the new development are projected to be substantially lower than the revenues generated,
resulting in a strong positive net fiscal impact. (pp. 6-7.)
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These recurring revenues would provide a stable, long-term funding source to support essential
municipal services including public safety, parks and recreation, public works, and community
development programs that benefit all City residents. Without the Specific Plan, the Town Center
would remain subject to the City's Housing Element Site Overlay, which establishes a maximum
density of 30 units per acre but does not provide the enhanced development incentives included
in the Specific Plan's Inclusionary Incentive Program. The Specific Plan's incentive structure is
what makes the scale of mixed -use development analyzed in the fiscal impact study —
approximately 2,055 residential units and 446,000 square feet of commercial space —financially
achievable, and therefore what makes the projected fiscal benefits to the General Fund
realistically attainable.
C. The Specific Plan Represents a Guiding Framework for Future Development Based
on Extensive Public Engagement
The Specific Plan would implement the City's 2040 General Plan, adopted by the City Council in
December 2019 following a three-year process of public outreach, engagement, and participation.
Throughout the General Plan update process, Diamond Bar residents consistently expressed
their desire for more local access to dining, entertainment, and retail establishments, as well as
for pedestrian -oriented, mixed -use activity centers. (Urban Land Institute Technical Assistance
Panel Report, p. 5.) As a result, the 2040 General Plan established a new vision for a pedestrian -
oriented "Town Center," where residents can enjoy activated spaces, urban housing opportunities,
food -oriented retail, restaurants, and entertainment.
The Specific Plan is the result of further public input from residents and local stakeholders.
(Specific Plan, § 1.10.) Through public workshops, periodic meetings, and a public website, the
public was encouraged to share their thoughts on the proposed Specific Plan. (Specific Plan §§
1.10.1-1.10.3.) Public comments and questions were noted and factored into the final plan.
(Specific Plan § 1010.3.)
The Specific Plan translates this community vision into implementable development standards
and design guidelines for the Town Center Mixed Use Area. The Specific plan is "crafted to reflect
the aspiration of the City's residents for a pedestrian friendly Town Center." (Specific Plan § 2.3).
To that end, the Specific Plan calls for (among other things): a "New Town Square", a public green
visible from Diamond Boulevard with a civic building; a "New Main Street," a north -south street
with 18' wide sidewalks and views of the San Gabriel Mountains; a "New Street Grid" that would
improve street intersection density, which is in turn associated with increased walkability and
decreased per capita air pollution from vehicle emissions (the existing condition is 65
intersections/square mile, the minimum density to achieve a walkable environment is 150
intersections/square mile, and the Specific Plan calls for 284 intersections/square mile); a "New
Torito Lane" that would extend the existing Torito Lane around a new neighborhood green crossing
and through the new public plaza; and a "New Neighborhood Adjacent to Golden Springs Drive"
that integrates elevated parcels into the larger Town Center through a public, accessible grand
staircase inspired by the Spanish Steps in Rome. (Specific Plan §§ 2.3.)
Without the Specific Plan, the existing zoning for the Town Center area would not implement the
2040 General Plan's vision or fulfill the community's expressed desire for apedestrian-oriented,
mixed -use Town Center with activated public spaces, diverse housing options, and walkable
streets.
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D. The Specific Plan Reflects Best Practices and Expert Recommendations for Town
Center Development
Following adoption of the Vision 2040 General Plan, the City sought guidance from the Urban
Land Institute Los Angeles (ULI-LA) to better understand market possibilities, implementation
strategies, and design frameworks for the Diamond Bar Town Center. (Urban Land Institute
Technical Assistance Panel Report ("TAP Report"), Diamond Bar Town Center, April 2021, p. 5.)
In April 2021, ULI-LA convened a Technical Assistance Panel ("Panel") of experts in land use, real
estate development, architecture, urban design, city planning, economic analysis, and
development financing to provide pro bono planning assistance. (TAP Report at p. 2.) Over a
week-long process, the panel toured the site, interviewed city officials, property owners, and
community members, analyzed the area, and presented findings to a joint session of the City
Council and Planning Commission. (TAP Report at pp. &9.)
The Panel identified comparable successful projects including The Village at Totem Lake (26
acres, 850 units, 400,000 SF retail), Santana Row (42 acres, 1,200 units, 680,000 SF retail), and
Santa Clara Square (92 acres, 1,300 units, 120,000 SF retail), demonstrating that mixed -use town
centers of similar or larger scale have been successfully developed in other California
communities. (TAP Report at pp. 20-21.) The Panel emphasized that "[a]II over the country and
world, successful town centers are surrounded by, and integrated with, denser residential
densities" and concluded its vision "includes higher residential densities than currently allowed in
the Vision 2040 General Plan" because "[t]hese higher residential densities would provide the
benefit of creating new housing options affordable at a mix of income levels" and "[t]he resulting
residential population would also drive demand for new restaurants, retail, walkability, and open
and gathering spaces in the Town Center." (TAP Report at pp. 7, 13.) The Panel recommended
that the City develop a Specific Plan "that provides both the certainty to incentivize investment
and the flexibility to ensure the financial feasibility of future development" and use "an urban
framework to guide the cohesive redevelopment of the Town Center, with urban -sized blocks,
residential density, and a priority on pedestrian movement." (TAP Report at p. 7.)
The Specific Plan incorporates these expert recommendations through its urban street grid (284
intersections per square mile compared to the existing 65), pedestrian features including the
grand staircase and 18400t wide sidewalks, mix of uses, minimum residential density of 30 units
per acre, and Inclusionary Incentive Program. By following guidance from experienced
professionals who evaluated comparable successful projects, the Specific Plan increases the
likelihood of achieving the community's vision and delivering anticipated benefits.
E. The Specific Plan Leverages Unique Site Characteristics and Regional Connectivity
The Town Center site possesses exceptional characteristics that the Specific Plan would leverage
to create a unique community asset. The ULI Technical Assistance Panel identified the site's
sloped topography as creating opportunities for design elements that take advantage of the
natural topography while optimizing the location of parking and creating space for pedestrian
plazas and paseos. (TAP Report at p. 7.) The Panel noted that "[w]ith dramatic vistas to the San
Gabriel Mountains to the north, these pedestrian spaces would be lined by creative and authentic
food uses —the kinds of uses that activate the atmosphere of a village, with people shopping,
eating, and celebrating." (TAP Report at p. 7.)
The Specific Plan leverages these exceptional site characteristics through deliberate design
strategies and development standards. The sloped topography identified by the TAP is utilized
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through the grand staircase connecting Golden Springs Drive to New Main Street to the north —
a public amenity that not only provides pedestrian connectivity between upper and lower portions
of the site but is envisioned as "a place in and of itself," offering dramatic views to the San Gabriel
Mountains while serving as a community gathering space. (Specific Plan § 2.3.5.) The Specific
Plan's street grid and block structure optimize parking locations by integrating structured and
subgrade parking that takes advantage of the site's grade changes, reducing surface parking from
the current 2,086 spaces that dominate the site and freeing land for the pedestrian plazas, paseos,
and activated street frontages recommended by the TAP.
The site's strategic location adjacent to the SR-57 and SR-60 interchange —where approximately
350,000 vehicles traverse during a typical weekday —provides exceptional regional visibility and
accessibility. (TAP Report at p. 11.) This strategic location positions the site to capture demand
from a broader market area than a typical neighborhood -serving commercial center. The site is
also proximate to the Gateway Corporate Center, which houses the South Coast Air Quality
Management District, City Hall, and several Fortune 500 companies, supplying a high
concentration of well -paying jobs and a large daytime workforce population that can support Town
Center retail and dining establishments. (TAP Report at p. 10.) The Panel noted that ongoing
phased improvements to the 57-60 interchange are "intended to significantly reduce congestion
and collisions while also preventing overflow traffic onto the surface streets of Diamond Bar,"
which would make the area more accommodating to pedestrian activity and support the Specific
Plan's vision for a walkable, mixed -use Town Center. (TAP Report at p. 11.)
The Specific Plan's mix of uses, including up to 2,055 residential units and approximately 446,000
square feet of commercial space, is specifically scaled to take advantage of the site's strategic
location adjacent to major regional transportation corridors and proximity to the Gateway
Corporate Center's daytime workforce population, creating the critical mass of residents and
daytime workers needed to support viable retail and dining establishments.
F. The Specific Plan Responds to Strong Market Demand
The Specific Plan responds to documented market demand for housing and retail uses in
Diamond Bar that has been unmet for decades. Market analysis prepared by RCLCO in
September 2022 found that "[d]evelopment of new housing in Diamond Bar has been limited over
the past two decades" with no new apartment communities delivered in the city since 1989 and
building permits decreasing precipitously between 1980 and 2000. (RCLCO Existing Conditions
& Market Demand Analysis "Demand Analysis", Diamond Bar Town Center, September 6, 2022,
p. 6.) This limited inventory has resulted in historically low apartment vacancy rates of just 0.8%,
and tight vacancies combined with strong rent growth averaging 5.3% between 2017 and 2021
indicate strong demand for new multifamily housing. (Demand Analysis, p. 6.) RCLCO concluded
that "the market has been underdeveloped for several decades and harbors inherent unmet
demand" and that "[t]he aging population of Diamond Bar is resultant of a lack of new housing"
such that "the introduction of a highly stratified and master -planned housing program should
induce the latent demand within the region that has been building." (Demand Analysis, p. 6.)
The Specific Plan would address this unmet demand by implementing a targeted maximum of
2,055 residential units in diversified housing types serving residents at multiple income levels and
life stages — the kind of "highly stratified and master -planned housing program" that RCLCO
identified as necessary to induce the region's latent demand. While the City's Housing Element
Site Overlay establishes the entitlement framework for residential development in the Town
Center, it alone does not provide the master -planned structure, diversified product mix, or
development incentives needed to capture this demand at meaningful scale. Given the City's
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current lack of a central retail corridor or true town center, the Diamond Bar Town Center has the
opportunity to capture a broad demand pool for retail, dining, hospitality, and multifamily housing
with limited competition. (Demand Analysis, p. 6.) By providing new housing options in a cohesive
mixed -use environment —options that have been unavailable in Diamond Bar for over three
decades —the Specific Plan would allow younger households to move into the community, enable
existing residents to downsize while remaining in Diamond Bar, and accommodate essential
workers and the daytime workforce serving the Gateway Corporate Center and other Diamond
Bar employers who currently cannot afford to live in the City.
Conclusion
The City of Diamond Bar has balanced the Project's benefits against the Project's significant
unavoidable impacts. The City Council finds that the proposed Project's benefits outweigh the
Project's significant unavoidable impacts, and these impacts, therefore, are considered
acceptable in light of the Project's benefits. The City Council finds that each of the benefits
described above is an overriding consideration, independent of the other benefits, which warrants
approval of the Project notwithstanding the Project's significant unavoidable impacts.
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XI REFERENCES
California Air Pollution Control Officers Association. December 2021. Handbook for Analyzing
Greenhouse Gas Emission Reductions, Assessing Climate Vulnerabilities, and
Advancing Health and Equity.
https:Hcaleemod.com/documents/handbook/full_handbook.pdf
California Building Standards Commission. 2023. Revision Record for the State of California.
2022 Title 24, Part 9, California Fire Code, https://www.iccsafe.org/wp-
content/uploads/errata_central/2022-California-Fire-Code-Part-9-Errata-eff.-January-
2023-5590S221. pdf
City of Diamond Bar. 2019. Diamond Bar Comprehensive General Plan Update and Climate
Action Plan Draft Environmental Impact Report.
https://ceqanet.opr.ca.gov/2018051066/2
City of Diamond Bar. 2019. Diamond Bar General Plan 2040.
https://www.diamondbarca.gov/961/General-Plan-2040
City of Diamond Bar. 2019. Diamond Bar General Plan 2040: Community Character &
Placemaking. https://www.diamondbarca.gov/DocumentCenterNiew/7090/3-
Community-Characterr?bidld=
City of Diamond Bar. 2022. Diamond Bar General Plan 2040 Housing Element Update 2021-
2029. https://www.aiamonaDarca.gov/963/Housing-Element-Update
City of Diamond Bar, 2023. City of Diamond Bar General Plan Update Existing Conditions
Report — Volume 111.
https://www.diamondbarca.gov/DocumentCenterNiew/7518/General-Plan-Existing-
Conditions-Report---Volume-III_011017?bidI&
City of Diamond Bar. November 21, 2023. First Amendment to the Professional Services
Agreement with MNS Engineers, Inc. for the Design of Diamond Bar Complete Street
Project (CIP# PW17400). City Council Agenda Report. Prepared by Daniel Fox, City
Manager, for Honorable Mayor and Members of the City Council.
https://diamondbarca.igm2.com/Citizens/Detail_LegiFile.aspx?Frame=&MeetinglD=1962
&MediaPosition=&ID=3375&CssClass= (accessed January 13, 2026).
City of Diamond Bar. December 17, 2024. Adopt Resolution Authorizing Execution of Funding
Agreements for State and Federal Funding, Approve WVWD Utility Agreement, Approve
LACFCD Trash Excluder Agreement and Adopt a Class 1 CEQA Exemption for the
Diamond Bar Boulevard Complete Streets Project, City Council Agenda Report.
Prepared by Daniel Fox, City Manager, for Honorable Mayor and Members of the City
Council.
https://diamondbarca.igm2.com/Citizens/Detail_LegiFile.aspx?Frame=&MeetinglD=2052
&MediaPosition=&ID=3615&CssClass= (accessed January 13, 2026).
City of Diamond Bar. November 4, 2025. Award of Construction Agreement for the Diamond Bar
Boulevard Complete Streets Project -CIP No. S1256 (Gentry Brothers, Inc.) and
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Diamond
Bar
Town Center Specific Plan
Findings of Fact and Statement of Overriding Considerations
February
25,
2026
Page XI-2