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HomeMy WebLinkAboutORD 14 (1990)ORDINANCE NO. 14 (1990) AN ORDINANCE OF THE CITY -COUNCIL OF THE CITY OF DIAMOND BAR ADOPTING AN INTERIM ZONING ORDINANCE PURSUANT TO THE PROVISIONS OF CALIFORNIA GOVERNMENT CODE 65858(a) AND MAKING FINDINGS IN SUPPORT THEREOF. A. Recitals. (i) On April 18, 1989, the City of Diamond Bar was established as a duly organized municipal corporation of the State of California. Thereafter, the City Council adopted its Ordinance No. 14, thereby adopting by reference the Los Angeles County Code as the ordinances of the City of Diamond Bar, including Title 22 thereof setting forth the applicable planning 1 and zoning regulations for the City of Diamond Bar. (Hereinafter said Title 22 shall be referred to as the "Zoning Ordinance.") (ii) With the recent incorporation of the City of Diamond Bar, the City Council has examined the existing Los Angeles County General Plan, Zone District Plan and Zoning Ordinance as it pertains to existing and potential development in the City of Diamond Bar. Such examination has revealed that there are areas within the City which do not provide a stable transition of densities, appropriate hillside development standards and/or uses and are, as such, incompatible with adjacent zones and uses. The City Council has not adopted the existing Los Angeles County General Plan (as the same would apply to the City of Diamond Bar) and action on development applications, as to required consistency to an adopted General 1 Plan, has taken place pursuant to the terms and provisions of California Government Code Section 65360. More specifically, residential developments within hillside areas which exceed a slope of ten (10) percent within the City are presently governed by the Zoning Ordinance. Lacking both an adopted General Plan, and consistent local development standards for review of development, such an approval scheme does not contribute to appropriate community development and would frustrate any effective long-range planning efforts within the City of Diamond Bar. (iii) In recognition of the need for effective long-range planning criteria, the City Council has directed staff of the City to study and formulate amendments to the Zoning Ordinance to assure adequate local review of and development standards for proposed residential development involving hillside areas which exceed a slope of ten (10) percent pending the adoption of the ultimate General Plan and development criteria for the City of Diamond Bar. (iv) There are presently pending applications, the approval of which would not conform to the contemplated General Plan or development approval scheme and would contradict the specific purposes for such Zoning Ordinance amendments and the adoption of a unified General Plan. Moreover, pending the completion of such amendments, it is foreseeable that further development proposals for residential development in hillside l areas will be submitted for property within the City which would E contradict the ultimate goals of the proposed Zoning Code amendments and General Plan. (v) This Council is concerned about the creation of an orderly and balanced development within the City of Diamond Bar. Accordingly, to protect the integrity of the ultimate General Plan and to assure the continued development stability of those properties within the City, this Council finds it is necessary to establish interim zoning policies to allow City staff the time necessary to investigate and formulate the above -referenced Zoning Ordinance amendments. (vi) All legal prerequisites prior to the adoption of this Ordinance have occurred. B. Ordinance. THE CITY COUNCIL OF THE CITY OF DIAMOND BAR DOES ORDAIN AS FOLLOWS: Section 1. The City Council hereby specifically finds that all the facts set forth in the Recitals, Part A, of this Ordinance are true and correct. Section 2,• The City Council further finds as follows: a. The City of Diamond Bar is presently developing a General Plan for development in the City of Diamond Bar. The ultimate goal of the General Plan is to provide a balanced and unified plan of development within the City of Diamond Bar and will ultimately upgrade the economic, social and cultural welfare of persons and properties within the City of Diamond Bar. The current Zoning Ordinance of the City of Diamond Bar does not 3 provide sufficient standards for application to City staff, Planning Commission or City Council review for the approval of hillside development in all residential zones within the City; b. There are presently pending applications for residential development in hillside areas which exceed a slope of ten (10) percent, the approval of which would contradict the ultimate goals and objectives of the General Plan and would not be subject to adequate local review under the current provisions of the Zoning Ordinance; and c. The approval of residential development on hillside terrain under the current provisions of the Zoning Ordinance -- would result in an immediate threat to the public health, safety i I or welfare of persons and property within the City of Diamond Bar. Section 1. The interim Zoning Regulations pertaining to residential development on hillside area which exceed a slope of ten (10) percent, as set forth on Exhibit "A" hereto, which are incorporated by reference herein as if set forth in their entirety, are hereby adopted. Section A. This Ordinance is enacted under the authority of California Government Code Section 65858(a) and shall be of no further force and effect forty-five (45) days from the date of adoption of this Ordinance unless the City Council has extended this Ordinance in the manner as provided in said Section 65858(a). 4 Section 5. This Ordinance is hereby declared to be an urgency measure pursuant to the terms of California Government Code Sections 65858(a) and 36937(b), and this Ordinance shall take effect immediately upon its adoption. Section 6. The City Clerk shall certify to the adoption of this Ordinance and shall cause the same to be posted in three (3) public places within the City of Diamond Bar pursuant to the provisions of Resolution No. 89-6. ADOPTED AND APPROVED this 16th day of n nh r , 1990. I, LYNDA BURGESS, City Clerk of the City of Diamond Bar, do hereby certify that the foregoing Ordinance was introduced and passed at a regular meeting of the City Council of the City of Diamond Bar held on the ig*h day of not-nhPr , 1990, by the following vote: AYES: COUNCIL MEMBERS: Papen, Kim, Horcher, Mayor Pro Tem Forbing and NOES: COUNCIL MEMBERS: None Mayor Werner ABSENT: COUNCIL MEMBERS: None ABSTAINED: COUNCIL MEMBERS: None 01 ATTEST: . \ City Clerk -of. he- '=- City of Dia�aond Bar - S�1011%0RDINTZNW3 6.6 5 EXHIBIT "A" CITY OF DIAMOND BAR INTERIM HILLSIDE MANAGEMENT ORDINANCE Section 1. Statement of Purpose The purpose of this ordinance is: a. To preserve and protect the views to and from hillside areas in order to maintain the identity, image and environmental quality of the City of Diamond Bar; b. To maintain an environmental equilibrium consistent with the native vegetation, animal life, geology, slopes, and drainage patterns; C. To facilitate hillside preservation through appropriate development standards and guidelines of hillside areas. The guidelines are not intended to be strict standards, but rather to provide direction and encourage development which is sensitive to the unique characteristics common to hillside properties, which include, but are not limited to slopes, land form, vegetation and scenic quality. Innovation in design is encouraged as long as the end result is one which respects the hillside and is consistent with the purposes expressed in this section and in the goals and objectives of the General Plan; d. To ensure that development in the hillside areas shall be concentrated in those areas with the least environmental impact and shall be designed to fit the existing land form; e. To preserve significant features of the natural topography, including swales, canyons, knolls, ridgelines, and rock outcrops. Development may necessarily affect natural features by, for example, roads crossing ridgelines. Therefore, a major design criterion shall be the minimization of such impacts; f. To provide a safe means of ingress and egress for vehicular and pedestrian traffic to and within hillside areas, with minimum disturbance to the natural terrain; I g. To correlate intensity of development with the steepness of terrain in order to minimize grading, removal of vegetation, land instability and fire hazards; h. To provide in hillsides, alternative approaches to conventional flat land development practices by achieving land use patterns and intensities that are consistent with the natural characteristics of hill areas such as slopes, land form, vegetation and scenic quality; and 1 Section 2. Hillside Management District. All property which contains grades in excess of lot shall comply with the following: A. Definitions: The following definitions shall apply to this Section: CONTOUR - A line drawn on a plan which connects all points of equal elevation. CONTOUR GRADING - A grading technique designed to result in earth forms which resemble natural terrain characteristics. Horizontal and vertical curve variations are often used for slope banks. Contour grading does not necessarily minimize the amount of cut and fill occurring. CUT - The mechanical removal of earth material. CUT AND FILL - The excavating of earth material in one place and depositing of it as fill in an adjacent place. DRIVEWAY - A means of access over private property to a single residential unit. EFFECTIVE BULK - The effective visual buk of a structure when seen from a distance of from below. ELEVATION - Height or distance above sea level. EROSION - The process by which the soil and rock components of the earth's crust are worn away and removed from one place to another by natural forces such as wind and water. FILL - A deposit of earth material placed by artificial means. FINISH GRADE - The final elevation of the ground surface after development, which is in conformity with the approved plan. GRADING - To bring an existing surface to a designed form by excavating, filling, or smoothing operations. HILLSIDE - Refers to a parcel of land which contains grades in excess of 10%. t 3 B. Hillside Designation The following are standards for hillside slope categories to ensure that development will compliment the character and topography of the land. The standards for one category may be applied to limited portions of the property in an adjacent category when a project is developed on property in more than one slope category. Slope Category 3i Natural Slope Site Standards 1. 10 to 14.9 Special hillside architectural and design techniques that minimize grading are required in these Slope Categories. 2. 15 to 19.9 Structures shall conform to the natural topography and natural grade by using techniques such as split level foundations of greater than 18 inches, stem walls, stacking and clustering. Conventional grading may be considered by the city for limited portions of a project when its plan includes special design features, extensive open space or significant use of green belts. 3. 20 to 24.9 Development within this category shall be restricted to those sites where it can be shown that safety, environ- mental and aesthetic impacts can be minimized. Use of large lots, variable setbacks and variable building structural techniques such as stepped foundations are expected. Structures shall be designed to minimize the visual impact of their bulk and height. The shape, materials, and colors of structures shall blend with the natural environment. The visual and physical impact of drive- ways and roadways shall be minimized by eliminating sidewalks, and reducing their widths to the minimum required for emergency access and following natural contours, using grade separations where necessary and otherwise minimizing grading. 5 Density "Average slope" of a parcel of land or any portion thereof shall be computed by applying the formula S = 0.00229 I Imo. A to the natural slope of the land before any grading is commenced, as determined from a topographic map conforming to national mapping standards and having a scale not less than one inch equals 200 feet and a contour interval not less than five (5' ) feet. The letters in such formula shall have the following significance: S = Average percent slope; I = Contour interval, in feet; L = Summation of length of contours, in feet; and A = Area in acres of the parcel being considered The density for property within this zone shall be computed in accordance with the following scale: Average Percent Maximum Density of slopes (D/O per Gross Acre) 10 - 14.9% 2.0 15 - 19.9% 1.6 20 - 24.9% 1.2 25 - 29.9% •8 30 - 34.9% .4 35 and over .1 Minimum Percent of Site to Remain in Natural State (No Cut or Fill) or Be Average Percent Developed Solely For Recrea- Slope of Site tional Purposes 0.0 - 14.9% I 32.5 $ 15.0 - 17.4% 40.0% 17.5 - 19.9% 47.5% 20.0 - 22.4% 55.•0% 22.5 - 24.9% 62.5% 25.0 - 27.4% 70.0% 27.5 - 29.9% 77.5% 30.0 - 32.9% 85.0% 32.5 - 34.9% 92.5% 35.0 and above % 100.0% 7 b. Land areas which have been subject to wild fire. -- C. Land areas which are above the hillside view line. d. Land areas which are subject to geologic hazard, landslide and debris over flow. e. Land areas which lie within a federally recognized blue line stream, or which contain significant riparian stream bed habitats or other established plant formations which constitute a significant natural feature or ecosystem or which contain rare or endangered species. f. Significant vegetation formations and habitat areas. g. Land areas which are within 100 feet of a significant ridgeline or hiking trail. h. Land areas containing significant archaeologic or historic sites. 3. Exemption - Other provisions of this subsection to the contrary notwithstanding, lots of record as of the date of adoption of this Ordinance shall be entitled to a minimum of one dwelling unit. D. uses Permitted. Subject to conditional use permit, the uses and structures permitted by the Hillside Management Ordinance shall be those uses permitted in the underlying base district. E. Hillside Management Standards and Guidelines. The following Hillside Management Standards and Guidelines are intended to ensure the appropriate management of hillside areas. The Standards are requirements for the use, development, or alteration of land in Hillside areas. The Guidelines are to be utilized to provide direction to encourage development which is sensitive to the unique characteristics common to hillside properties. The purpose for the Guidelines is to protect existing hillsides and to encourage innovation, to the extent that is, the erred result is one which respects the/hillside and is consisent with the goals and policies of this Ordinance. The Guidelines shall be used by the Planning Commission and the City Council in evaluating those development proposals for which it is proposed to go beyond the minimum standards herein specified. Exceptions to the standards specified herein may be approved, pursuant to the Conditional Use Permit (CUP) process, when the approving agency determines that such exceptions are not materially injurious to the intent of the standards and guidelines set forth herein. In granting any such exception, the approving agency shall set forth appropriate findings specifying the facts supporting its determination. 9 20 percent, 20 up to 25 percent, 25 up to 30 percent, 30% to 35% and 35 percent or greater. Also included shall be a tabulation of the land/area in each slope category specified in acres. Combining '8' and 'C' is not a permitted calculation -- -----------i SLOPE FORMULA IVU Average Cross Slope - Slope 'A' 5'!100' _ .05 = 5% Slope '8' 30'/20' - 1.50 = 150% - Slope 'C' 6'130' _ .2 = 20% 11 F. Both the slope analysis and slope profiles shall be stamped and signed by either a registered landscape architect, civil engineer, or land surveyor indicating the datum, source, and scale of topographic data used in the slope analysis and slope profiles, and attesting to the fact that the slope analysis and slope profiles have been accurately calculated and identified. G. A geologic and soils report, prepared by an approved soils engineering firm and in sufficient detail to substantiate and support the design concepts presented in the application as submitted. Additional environmental studies and investigations, such as, but not limited to, hydrologic, seismic, access/circulation, and biota research may also be required in order to help in the determination of the buildable area of a site. H. A statement of conditions for ultimate ownership and maintenance of all parts of the development including streets, structures and open spaces. I. In the event that no grading is proposed, i.e., custom lot subdivision, a statement to that effect shall be filed with a plan which shows possible future house plotting, lot grading, driveway design, and septic system location for each parcel proposed, to be prepared on a topographic map drawn at the same scale as the conceptual grading plan. J. When unit development is proposed, illustrative building elevations, that show all sides of the proposed structure(s) and which accurately depict the building envelope for each lot, shall be provided. K. The following items may be required if determined necessary by the Planning Director or Planning Commission to aid in the analysis of the proposed project to illustrate existing or proposed conditions or both: 1. A topographic model; 2. A line of sight or view analysis; 3. Photographic renderings; 4. Any other illustrative technique determined necessary to aid in review of a project. L. Exceptions to the filing requirements shall be determined by the Planning Director. 13 F. In the event the abatement is not performed as required in subsection C of this section, the City Council may instruct the Fire Marshal to give notice to the owner of the property upon which said condition exists to correct such prohibited condition and, if the owner fails to correct such condition, the City Council may cause the same to be done and make the expense of such correction a lien on the property upon which such conditions exist. G. Require special construction features in the design of structures where site investigations confirm potential geologic hazards. B. Grading The following standards define basic grading techniques which are.consistent with the ordinance and avoid unnecessary cut and fill. Limitations on project grading amounts and configurations will be decided on a case-by-case basis under the conditional use process. Standards. i. No finished slopes greater than fifty percent (500 or 2:1) may be created except beneath a structure where the maximum created slope is limited to sixty-seven percent (67% or 1-1/2:1) or less. ii. Grading shall be phased so that prompt revegetation or construction will control erosion. Where possible, only those areas which will be built on, resurfaced, or landscaped shall be disturbed. Top soil shall be stockpiled during rough grading an used on cut and fill slopes. Revegetation of cut and fir slopes shall occur within three (3) months to the satisfaction of the City. iii. Grading operations shall be planned to avoid the rainy season, October 15 to April 15. Grading permits shall only be issued when a plan for erosion control and silt retention has been approved by the City Engineer without regard to time of year. iv. No excavation or other earth disturbance shall be permitted on any hillside area prior to the issuance of a grading permit with the exception of drill holes and exploratory trenches for the collection of geologic and soil data. These trenches are to be properly backfilled and in addition, erosion treatment provided where slopes exceed twenty (20) percent. 15 b. Guidelines. i. Contour grading techniques should be used to provide a variety of slope percentage and slope direction in a three dimensional undulating pattern similar to existing, adjacent terrain. Hard edges left by cut and fill operations should be given a rounded appearance that closely resembles the adjacent natural contours. ii. Where possible, graded areas should be designed with manufactured slopes located on the uphill side of structures, thereby, hiding the slope behind the structure. THIS Larger manufactured slopes should be located on the uphill side of the structure to reduce the appearance of 9r•d+pg from the street Slopes Should be rounded to f provide a more natural appearance Street NOT THIS ay � Street 17 3. The following factors shall be taken into considertaion in the design of a project: a. When space and proper drainage requirements can be met with approval by the City Engineer, rounding of slope tops and bottoms shall be accomplished. b. When slopes cannot be rounded, vegetation shall be used to alleviate a sharp, angular appearance. C. A rounded and smooth transition shall be made when the planes of man-made and natural slopes intersect. d. When significant landforms are "sliced" for construction, the landforms shall be rounded as much as possible to blend into natural grade. e. Manufactured slope faces shall be varied to avoid excessive "flat -planed" surfaces. 4. No manufactured slope shall exceed 30 feet in height between terraces or benches. �..._ Retain the integrity Aver -emphasised vertical NOT THIS structures disrupt the natural silhouette at the hillside �. . moi` 19 C. Hard edges left by cut and fill operations should be given a rounded appearance that closely resembles the natural contours of the land. THIS Small irregular berm accentuates the top of the slope 1 \\ Variety in slope an grading creates a Q natural appears ee� more resembling 40 I nature Drainage features are \' obscured NOT THIS i ox�o�o Landscaping accentuates Drainage C� contour undulation features become very visible Engineered slope banks look forced i and unnatural , Use of radii and uneven slopes Use of angles and uniform slopes d. Manufactured slopes adjacent to roadways should be modulated by sufficient berming, regrading, and landscaping to create visually interesting and pleasing streetscapes. THIS Variety in undulating slope bank creates / pleasing roadscap I 21 NOT THIS j Straight slop• bank heightens monotony of road' way landscape THIS NOT THIS a homeowners association, otherwise the drainage shall be conveyed to a public easement. The easement width shall be determined on an individual basis and shall be dependent on appropriate hydrologic studies and access requirements. b). Project boundaries - Onsite drainage shall be conveyed in an improved open V-swale, gutter, which has a naturalized appearance, or within an underground pipe in either a private drainage easement, which is to be maintained by a homeowner's association, or it shall be conveyed in a public easement. The easement width shall be determined on an individual basis and shall be dependent on appropriate hydrologic studies and access requirements. Variable i Use of native rocks to 1 naturalize man-made brow ditch Typical brow ditch with A.C. or concrete liner W _ 23 Section 6. a. ii. Natural drainage courses should be preserved and enhanced to the extent possible. Rather than filling them in, drainage features should be incorporated as an integral part of the project design. Access and Parking. Standards. 'THIS r or 3' mire r :J1....13-inax i. Driveway grades up to a maximum of twenty (20) percent are permitted, and shall be aligned with the natural contours of the land. Proper design considerations shall be employed, including such items as vertical curves and parking landings. In any case, parking landings shall be utilized on all drives over ten (10) percent grade. ii. Driveways shall not be permitted which exceed twenty (20) percent slope except that one length, not at the point of access, of not more than ten (10) feet may have a slope of twenty-two (22)percent. 25 Grooves for traction shall be incorporated into the construction of driveways with a slope of twenty (20) percent or greater, a coarse paving matter into the construction. 3' max iv. Where retaining walls are necessary 3' max adjacent to roadways or within V7 P street setbacks, they shall be str•.t limited to three (3) feet in height in order to avoid obstruction of motorists' and pedestrians' field of view, and to create an aesthetically pleasing streetscape. No more that J' three (3), three (3) foot high str••t terraced or stepped retaining walls shall be utilized which are separated by a minimum of three (3) feet and appropriate landscaping. Slopes not greater than fifty (50) percent (or 2:1) will be permitted upon review and approval by the Fire Marshall. 25 straight alignments or by building switch -backs on visually prominent hillsides, split sections and parking bays should be utilized in the layout of hillside streets. THIS Reduce grading by / aligning roads along natural grades NOT THIS Roads and hillside grading Avoid running counter to steep grades To get from A to S, route selection would be somewhere between perpendicular and Parallel to the contours 27' A To get from A to S, route selection would be somewhere between perpendicular and Parallel to the contours 27' Section 7. Trails 1. Trails are an integral part of a hillside area and provide recreation areas for equestrian, hiking and biking uses. They can also function as a means to take up grade or to convey drainage. In hillside areas, it is -not always necessary to provide full improvements for trails. A more natural experience may be achieved, and the amount of grading required can be reduced, by providing minimal improvements in appropriate areas, such as undevelopable, steep slopes. 29 LA " r � 29 Section 9. Site Design a. Standards. THIS i. The dimensions of a building parallel to the direction of the slope shall be maximized in order to limit the amount .of cutting and filling and to better fit the house to the natural terrain. NOT THIS Terraced decks do not 6' e• Overhanging decks increase building bulk ��. make building seam more Effective bulk with . massive t or without decks Effective bulk Building correctly fits into the ground and —� minimizes the effect on the hillside 1 Use of roof decks, low level decks, and side of 1 building decks Terracing reduces bulk Jill "'4W4% - Effective bulk v , Effective bulk Smaller overhangs for individual floors or windows help break-up mass and protect against excessive sunlight High profile building stands out on the hillside Avoid decks hanging from the downhill side with long pole supports Cantilever makes building appear taller, more monumentat• _ cnR Effective bulk Ic.F Excessive roof overhang J results in additional � 1f visual bulk 31 Effective bulk _ Section 10. Architecture a. Standards. 35j i. The building envelope for all structures shall be as follows: 1. Downhill lot - A maximum/ height of thirty-five (35) feet as measured from natural grade at the front setback, extending towards the rear of the lot. The maximum height at the side setbacks shall be twenty (20) feet extending up to the center of the lot at a forty-five (45) degree angle to a maximum height of thirty-five (35) feet as measured from natural grade. BUILDING ENVELOPE FOR DOWNHILL LOT 35' \ e 45 Minimum front setback I iS R Downhill Section \ �� Minimum side setback i Rears setb*ck Street Elevation 33 ii. The building shall be terraced to follow the slope. iii. Architectural treatment shall be provided to all sides of the structure visible from adjacent properties, roadways or public rights of way. iv. Exterior structural supports and undersides of floors and decks not enclosed by walls shall be permitted provided fire safety and aesthetic considerations have been adequately addressed. V. Exterior flood lighting for safety shall be located and shielded so as not to shine on adjacent properties. Decorative lighting to highlight a structure is prohibited. THIS Large roof areas broken up Use of natural materials and window placement in small increment create interesting small seal* patterns Break up massing of structural elements to more closely app►o:imate the natural slope Stone foundations and retaining wall' Wale to the ground 35 NOT THIS Massive roof area is very visible in contrast to the natural slope Large facade of one material, even if modulated by windows, seems plain vi. To the extent possible, the width of a building measured in the direction of the slope, shall be minimized in order to limit the amount of cutting and filling and to better "fit" the house to the natural terrain. THIS Building pulls back from steeper slopes and ravines an rr+a r.iu.id. y Minor building protrusions which are perpendicular to the contours are acceptable but should be stepped or Inset in the hillside Building is parallel with NOT THIS the contours Building is perpendicular to the contours 37 J THIS NOT THIS vi. Landscaping shall be used to screen views of downslope building elevations. When the structure height exceeds twenty (20) feet from finished grade on a downslope, additional landscaping is required and a landscaping plan shall be submitted for review with the submittal package. vii. Slopes with required planting shall be planted with informal clusters of trees and shrubs to soften and vary the slope plane. Where slopes are 2:1 and five (5) feet or greater in height, jute netting shall be used to help stabilize planting and minimize soil erosion. viii. Native vegetation shall be retained and supplemented within canyons and along natural drainage courses as allowed by state and federal resource agencies (State Department of Fish & Game, U. 5. Fish and Wildlife, U. S. Army Corp. of Engineers). Planting naturally follows the average slope Open see-thru fencing that blends into the natural environme 3.5'ma:imum retaining wall Screening required• Tranfitlon area ` h Highly visible solid wall Over 3.3'(not allowed) No screening Clear cut separation between natural condition and developed area with no transition Natural landform planting should be used to soften manufactured slopes, reduce the impact of development on steep slopes or ridgelines, and provide erosion control. THIS -A 1 ry �- S, _ .h Landform planting Irregular visual plane in cross-section ' I Sect NOT THIS Conventional planting L 41