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HomeMy WebLinkAboutORD 07 (1992)ORDINANCE NO. 07(1992) AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF DIAMOND BAR ADOPTING A HILLSIDE MANAGEMENT (GRADING) ORDINANCE 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 and, on that date, the City Council adopted, by reference, the Los Angeles County Code as the ordinances of the City, including Title 22 thereof pertaining to Planning and Zoning Regulations for the City of Diamond Bar. (ii) on October 16, 1990, the City Council enacted its Ordinance 14 (1990), pursuant to California Government Code § 65858, to establish policies, standards, techniques and requirements for grading activities in hillside areas of the community. Said Ordinance No. 14 (1990) was subsequently extended pursuant to California Government Code § 65858. (iii) During the pendency of the interim ordinance, City staff has conducted a review and analysis of the management of hillside areas which would conform to the goals and objectives of the Geneial Plan pursuant to Ordinance No. 4 (1992), further the benef tial interests of the City and satisfy the objectives and intent of the General Plan. Staff's work product was reviewed and approved by the Planning Commission of the City of Diamond Bar at its regularly scheduled meeting of October 26, 1992. The Planning Commission has recommended that the City 1 Council adopt the Hillside Management Ordinance as set forth herein. (iv) The City Council desires to adopt the Hillside Management Ordinance as discussed hereinabove. (v) This Council has conducted, and concluded, a duly noticed public hearing with regard to the Hillside Management Ordinance. (vi) All legal prerequisites to the adoption of this Ordinance have occurred. B. Ordinance. NOW, THEREFORE, the City Council of the City of Diamond Bar does ordain as follows: Section J: In all respects as set forth in Part A, Recitals, hereinabove. Section 1: The City Council hereby finds and determines that the adoption of this Ordinance is categorcally exempt from the requirements of the California Environmental Quality Act of 1970, as amended, and the Guidelines promulgated thereunder pursuant to § 15308 of Division 6 of Title 14 of the California Code of Regulations. Section 3: The City Council hereby adopts the Hillside Management Ordinance to read, in words and figures, as set forth in Exhibit "A" attached hereto and incorporated herein by reference. It 2 8eetion 4: The City Council hereby declares that should any provision, section, paragraph, sentence, or word of this Ordinance be rendered or declared invalid by any final court action in any court of competent jurisdiction, or by means of preemptive legislation, the remaining provisions, sections, paragraphs, sentences, and words of this Ordinance shall remain in full force and effect. 8eation ¢: It shall be unlawful for any person, firm, partnership, or corporation to violate any provision or to fail to comply with any of the requirements of this Ordinance. Any person, firm, partnership or corporation violating any provisions of this Ordinance or failing to comply with any of its requirements shall be deemed guilty of a misdemeanor and upon conviction thereof shall be punished by a fine not exceeding one thousand dollars ($1,000.00), or by imprisonment not exceeding six (6) months, or by both such fine and imprisonment. Each and every person, firm, partnership, or corporation shall be deemed guilty of a separate offense for each and every day or any portion thereof during which any violation of any of the provisions of this Ordinance is committed, continued or permitted by such poarson, firm, partnership or corporation, and shall be deemed punishable therefor as provided in this Ordinance. Se-- o- It The violation of any of the provisions of this Ordinance shall constitute a nuisance and may be abated by the City through civil process by means of restraining order, 3 preliminary or permanent injunction or in any other manner - provided by law for the abatement of such nuisances. fiction Z: 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 89-6B. 199 L ADOPTED AND APPROVED this 5th day of January , Mayor I, LYNDA BURGESS, City Clerk of the City of Diamond Bar, do hereby certify that the foregoing Ordinance was introduced at a regular meeting of the City Council of the City of Diamond Bar held on the 15th day of December , 1992, and was finally passed at a regular meeting of the City Council of the City of Diamond Bar held on the 5th day of January , 1993, by the following vote: AYES: COUNCIL MEMBERS: MacBride, Forbing, Werner, Mayor Pro Tem Papen, Mayor Miller NOES: COUNCIL MEMBERS: None ABSENT: COUNCIL MEMBERS: None ABSTAINED: COUNCIL MEMBERS: None ATTEST: C' Clerk*- Z�t f- Diamond. Bar _ M 10111ID'00R M 6.6.1 4 CITY OF DI7 XOND BAR ORDINANCE NO. 7 (1992 ) HILLBIDs MUMOMIMT ORDINANCE Section 1. 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 and 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 j� 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, where possible, 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 undeveloped terrain; g. To correlate intensity of development with the steepness of terrain in order to minimize the impact of grading, unnecessary 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 i. To encourage the planning, design and development of sites that 1 anor=Jm s. IM i. To encour age the planning, design and development of sites that provide maximum safety with respect to fire hazards, exposure to geological and geotechnic hazards, drainage, erosion and siltation, and materials of construction; provide the best use of natural terrain; and to prohibit development that will create or increase fire, flood, slide, or other safety hazards to public health, welfare, and safety. J- It is therefore the intent to establish general and specific guidelines with this ordinance which will ensure that development will complement the character and topography of the land. Specifically the city desires the application of good hillside planning and the use of the concept of "Landform Grading and Revegetation" in designing any development proposal. section 2. Applicability The regulations contained herein shall be applicable to all parcels of land containing grades in excess of ten percent (lot). Section 3. Permitted Uses The uses permitted by the Hillside !Management Ordinance shall be those uses permitted within the General Plan Land Use classifications for the property and the base zone designation subject to Conditional Use Permit (CUP) approval. Section 4. Density The maximum number of residential dwelling units which may be permitted to be constructed on a given parcel of land shall be the calculated development pursuant to the General Plan Land Use classification limit less the number eliminated due to environmental constraints and as determined by this ordinance. section s. environmental Constraints The maximum number of residential dwelling units can be affected by the impact of the following development constraints, as determined by environmental assessment, unless such development.constraints can be shown to have been eliminated or mitigated to the satisfaction of the Planning Commission or the City Council: 1. Land areas subject to inundation during a 100 -year storm 2. Land areas which are above the hillside view line. 3. Land areas which lie within a federally recognised 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. 4. significant vegetation formations and habitat areas. 2 iiaLS.:M r- 5. Land areas which are within loo feet of a prominent ridgeline or hiking trail. i 6. Land areas containing significant archaeologic or historic sites. section t. 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. Single dwelling unit development shall be administered in conjunction with the provisions of Chapter 22.72 of the Diamond Bar Municipal Code (Ordinance No. 5(1990) Development Review.) Section 7. Administration This Ordinance shall be administered in conjunction with the provisions Of Chapter 22.56 of the Diamond Bar Municipal Code. Where a conflict or inconsistency exists, the more restrictive regulation shall apply. Where the grading ordinance conflicts with the Hillside Management Ordinance, the latter shall prevail. Section s. ailiside Management standards and guidelines The 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 the hillside properties. 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 planning Commission or City Council determines that such exceptions are not materially injurious to the intent of the standards and guidelines not forth herein. In granting any such exception, the Planning Commission or City Council shall set forth appropriate findings and facts supporting its determination. The Planning- Commission or City Council may vary from the standards contained hereinand determine that the literal enforcement of the provisions of this Ordinance, for parcels which may be too small and of a configuration which would create a hardship provided that a variation from the strict application of the Code be accompanied by reduction in the maximum permitted density to the extent does" necessary to maintain the intent of the Ordinance. variations may include modification of the setback requirements to achieve clustering of development on the parcel, in order to maintain grading, drainage, siting and circulation objectives of the Ordinance; except that residential structures shall be sited and designed in a 3 ADOF n UL s, IM manner which will, in the judgment of the Director, maintain a vertical— and horizontal distance from other residential structures which will Provide a reasonable degree of privacy, light and air between residential structures. Where development is proposed for a parcel which adjoins one or more vacant, developable parcels, cooperation of the respective property - owners is encouraged in the planning of the road network, utilities plan and open space program for the area as a whole. The City may consider variations from the strict application of the provisions of this Ordinance as may be needed to achieve cooperation among all contiguous property owners of vacant, developable properties, to the extent that such variation may bettor achieve the objectives of this Ordinance. section s. Definitions The following definitions shall apply to this Ordinance: CITY EEGXN ER - shall mean the City Engineer of the city of Diamond Har. CONTOUR - Jul line drawn on a plan which c equal elevation. onnects all points of CUT - A portion of land surface or area from which earth has been removed or will be removed'by excavation. The mechanical removal,_ of earth material. OOT AM FILL - The excavating of earth material in one place and depositing of it as -fill in an adjacent place. DIRECTO! - Shall mean the Director of Community Development of the City of Diamond Bar-. DAIVMMT - A private roadway providing access for vehicles to a Parking space, garage, dwelling or other structure. EFFECTIVE SM& - The effective visual bulk of a structure when seen from a distance or fres above or below. ELMTian - 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 on* place to another by natural forces such as wind and water. WILL - A deposit of earth material placed by artificial means. FIYISE OME - The final elevation of the ground surface after grading, which is in conformity with the approved plan.. GRADING - To king an existing surface to a designed form by excavating, fillinq, or smoothing operations. (Sas Figure 1) HILLSIM - A parcel of land which contains grades in excess of 104. NATUMM SLOPE - A slope which is not man -mads. A natural slope may retain natural vegetation during adjacent grading operations or it may be partially or completely removed and replanted. PAD - A level area created by grading to accoaodats development. RIDGE - A long, narrow, comMicuous elevation of land. ROADWAY - A means of access over private property to more than one ~' residential unit. SLOPE - An inclined ground surface, the inclination of which is expressed as a ratio of horizontal distance (run) to vertical distance (rise), or change in elevation. The percent of any given 4 ADOFM a& S. IM slope is determined by dividing the rise by the run, multiplied by 100.(See Figure 2) SLOPS* lOti-JMDM - A manufactured slope consisting wholly or partially of either cut or filled material. SLOPS 22ANSITZO1: The area where a slope bank meets the natural terrain or a level graded area either vertically or horizontally. PROKIN AIDaA: A ridge or hill location which is visible from a major arterial, secondary, or collector street, which forms part of the skyline or is seen as a distinct edge against a backdrop of land at least 300 feet horizontally behind it, or is so designated by the Planning Commission or City Council. I. Conventionally graded slopes are characterized by essentially linear, flat slope surfaces with unvarying gradients and angular slope intersections. Resultant pad configurations are rectangular. 2. Slope drainage devices are usually constructed in a rectilinear configuration in exposed positions. 3. Landscaping is applied in random or geometric patterns. for aF stag lom OC scot 5 ADOFM Jm s, IM 1. contour-qraded slopes are basically similar to conventionally graded slopes except that in plan the slopes are curvilinear rather than linear, the gradients are unvarying and profiles are Planar, transition zones and slope intersections have generally some rounding applied. Resultant pad configurations are mildly curvilinear. 2. Slope drainage devices are usually constructed in a geometric configuration and in an exposed position on the slope face. 3. Landscaping is applied in random or geometric patterns. 'top OF stop£ IM OP Soff I. Landform Gradinq replicates the irregular shapes of natural slopes resultinq in aesthetically pleasinq elevations and profiles. Landform -graded slopes are characterized by continuous series of concav`G and convex forms interspersed with sounds that blend into the profiles, non -linearity in plan view and varying slope gradients, -and significant transition zones between man-made and natural slopes. Resultant pad configurations are irregular. 2. Slope down -drain devices either follow "natural* lines of the �.. slopes or are tucked away in special Swale and bars combinations in order to conceal the drains from view. Enposed segments in high visibility areas are treated with natural rock. 6 ADOFM a.. S. 1993 3. Landscaping becomes a "revegetation" process and is applied in patterns that occur in nature: trees and shrubs are concentrated largely in concave areas, while convex portions are planted mainly with groundcovers. -14-OP rN-I toE OF st oPE The intent of the ordinance, is to incorporate the basic principles of the "Landform Grading and Revegetation" concept in the design and construction of hillside development projects so that they will be in harmony with the natural topography and reflect plant distribution patterns. The general principles of "Landform Grading and Rsvegetation: incorporate the following elements: a. The basic land plan "flows" with the natural topography rather than against it. This means that street patterns and building pad confiqurations follow the underlying topographic features rather than cutting across them. b. All manufactured cut and fill slopes exceeding nine (9 0 ) feet in height which, will be, either exposed to permanent public view or are adjacent to environmentally sensitive areas, will be designed with features characteristic of natural slopes so that their ultimate appearance will resemble a natural slope. This will include slopes along streets and highways, slopes adjacent to parks, schools, open spaces, and other public facilities and other prominent and highly visible slopes. Sideyard slopes and low (less .than 250 in height) rearyard slopes whose view is blocked by future structures need not -- have landform design applied. C. Slope drainage devices such as down drains and interceptor drains shall be designed so that they are built into the natural slope features and become hidden from view. This 7 enotMJaL s, IM (Sae Figures 13, 14, 15 i 16) d. Terracing and the associated concrete drainage devices suck. as terrace drains, down drains and interceptor drains distract from efforts to give cut and fill slopes a natural appearance. e. Landscaping will not be applied in a conventional pattern, but rather those resembling the natural plant distribution patterns. Trees or shrubs will be clustered in the swaled (concave) components of the slope along with ground cover. Ground cover, only, will be applied to the protruding (convex) portions. (See Figures 31) Section 10. slope analysis AJ__ calculating Iverage ale-. Using the following formula, calculate the average slope of the entire parcel. I Contour interval in feet Slope - 0.002296 Z L L - Summation of length of all A contours in feet A - Area in acres of parcel beinq considered The following are standards for hillside slopes in areas that will not be landform graded. These categories ensure that development will complement the character and topography of the land. standards for one cat The the property in an adjacent mcat�ory applfed to limited portions of on property in more than one sloes when a project is developed Pe category. slope CatRUM & Natural Slone Site Standards 1• 10 to 24.9 Special hillside architectural and design techniques that minimize grading are required in this Slope Category. 2. 25 to 39.9 Structures shall conform to the natural topography and natural qrade by using techniques such as split level foundations o greater than 18 inches, stem walls, stacking and clusterinq. Conventional gradinq 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. 40 to 49.9 Development within this category shall be 8 ADOFM Im 5. IM 3. 40 to 49.9 Development within this category shall be restricted to those sites where it can be shown that safety, environmental 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 driveways 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. 4. 50 and over This is an excessive slope condition and development may be extremely limited. Figure 2 Slope ratio percent slope and degree of slope are shown for some hillsides of varying steepness 1� D "M CH40mmu) s 5�1 20 i{ 3: i 33 t8 2� ( SO 25 1.5:1 67 34 1:1 iao 4-6� 9 ADOFMJr. s, IM Section 11. Grading The followinq 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 landform grading slope design standards include: When convex shaped natural features, i.e., protruding ridgelines are cut, the residual landform should not be a flat slope face, but rather should be restored to resemble the original. This will require more than just rounding at the edges but, in affect, reconfigurinq it so the final result will give the appearance of a protruding ridgeline. (See Figure 3) H • CAN= FT11": Fill slopes shall not be placed perpendicular across a canyon. Such straight line cut off fill slopes shall not be made to appear like a dam. The terminus of the fill shall, instead, be concave in shape to restore the canyon appearance. This concave configuration shall be. in combination with the use of substantially flatter slope ratios (4:1, 3.5:1, 3:1) at or near the center of this indentation. Symmetrical or unsymmetrical concave configurations shall be used depending upon the adjoining or underlying topographic characteristics. (See Figure 3) C • TRANamoN-Aaam Minimal radius rounding at the edges of cut and fill slopes is not acceptable. Proper transitioninq to natural slopes shall be achieed through the"use of radii or irregular curvilinear shapes that will blend into the adjoining topography tangentially and not create abrupt changes. (See Figure 3) 10 ecorM JoL s. IM FIGURE 3 SLOPE DESIGN AccEP AA#i f Gut X \ CAAvroa F/[t tMNsir-IvAv zove ONACCERM044 11 ADO"W hm s, IM i .000 tMNsir-IvAv zove ONACCERM044 11 ADO"W hm s, IM FIGURE 4 SINGLE FAMILY GRADING CON VRAIVONAl- 1 AMPAVAM • emN v/EW .016144016 view 9 12 ,Donau am s, IM FIGURE 5 MULTI FAMILY GRADING CONI�NT/o/Vi4L II I-AAWPOAM • tpG/;N VIOW 06 -14wo WOW TWA& 5, im • �_ • !, •• Due to the fact that the landform grading designs require the use of variable slope ratios at greater than 2:1, creates valleys, and concave indentations on building pad areas, it can result in loss of usable area. In addition, engineering and construction costs may increase. Two methods will be permitted to offset this loss, they are as follows: 1. Pad areas lost due to concave indentations will be counted towards meeting the landscape area requirements of development proposals for a given pad. 2. Segments of a cut or fill slope will be permitted to be designed with variable slope ratios less than 2:1, but not less than 1.5:1 within the following guidelines: ae the geotechnical engineer will certify that slopes so designed will meet standard stability requirements. b. overall ratio from toe to toe Will be 2:1 or greater. C. ratios greater than 2:1 will also be used in the slope design (see Figure 6) 14 ADOFM 16L s, IM FIGURE 6 =UCPL! OF VARIABLR MLOPE RATION 15 ADOPM t o• s, M X. standards 1. No finished slopes greater than fifty percent (504 or 2:1) may be created except adjacent to a structure where the maximum created slope is limited to sixty-seven percent (674 or 1h:1) or less. 2. 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 land- scaped shall be disturbed. Top soil shall be stockpiled during rough grading and used on. cut and fill slopes. Revegetation of cut and fill slopes shall occur within three (3) months to the satisfaction of the City. 3. 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. 4. 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. 5. No point on any structure subject to the provisions of this Section shall be closer to a prominent ridge than one hundred (100) feet measured horizontally on a topographic map or fifty (50) feet measured vertically on a cross section, whichever is more restrictive. And in no case, shall the roof line or any other portion of a structure extend above the line of sight between a ridge line and any public right of way, whether said ridge -line is above or below the right of way. 6. Lot pad gradinq is limited to the boundaries of the structure's foundation, vehicle parking space and a yard area as shown on the approved grading plan. 7. Retaining walls associated with lot pads are limited to: a. vpslope (from the structure) walls not to exceed four (4) feet in height. Terraced retaining structures may be utilized which are separated by a minimum of three (3) feet and appropriate landscaping. b. Downslope (from the structure) walls not to exceed four (4) feet in height. where an additional retained portion is necessary due to unusual or extreme conditions, (such as lot configuration, steep slope, or 16 ADOFM Is& 3, IM road design) then the use of terraced retaining structures shall be considered on an individual lot basis. Terraced walls shall not exceed three (3) feet in height and shall be separated by a minimum of three (3) feet and appropriate landscaping. Terracing shall not be used as a typical solution within a development. 8. Lot lines shall be placed two feet beyond top of major slope areas within public view corridors to help ensure their maintenance by the downhill owner. F. guidelines 1• where possible, graded areas should be designed with manufactured slopes located on the uphill side of structures, thereby, hiding the slope behind the structure. 17 eoonmD Im s, 19" Figure 7 7'ff/s UOM9 SNovAP by % M WAeC L/4!W M 4WA4Gt4V0 Suvjw, SVQW 00 LocAMP ON *VS W#IAL S/DE � �� yHk S71gGGTllf,� 7a /SEDUGC 7� sr�et Not ty,5 1 2. Retaining walls are limited to 4 feet in height. Terraced retaining structures may be utilized which are separated by a minimum Of 3 feet and appropriate landscaping. Retaining walls hidden by structures may be permitted. Figure 8 (also see Figure 17) /-R/S NOr 7V/S 18 ADMED e.. S, IM 3. One downslope from the structure not to exceed 3 1/2 feet in height. Where an additional retained portion is necessary due to unusual or extreme conditions, (such as lot configuration, steep slope, or road design) then the use of terraced retaining structures shall be considered on an individual lot basis. Terraced walls shall not exceed 3 feet in height and shall be separated by a minimum of 3 feet and appropriate landscaping. Terracing is not to be used as a typical solution within a development. 4. on lots sloping with the street, and other configurations not discussed above, one retaining wall, not to exceed 3 1/2 feet in height may be used in a side yard where necessary (also see roadway). 5. Walls which are an integral part of the structure may exceed 8 feet in height; however, their visual impact shall be mitigated through contour grading and landscape techniques. 6. The following factors shall be taken into consideration 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, vegetations 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 such as possible to blend into natural grade. e. Nanufactured slope faces shall be varied to avoid excessive "flat -planed" surfaces. 7. No manufactured slope shall exceed 30 feet in height between terraces or benches. 19 ADOPM h& s. IM Figure 9 /W?WA/ MV INr-w&AetY or 7WE AA-P&A4L SLOPE Not mis oVAVL -AwAW snco v67�.rrc PISAvAl- O)V& N nVAL S/LMOUMY,E OF AV M"64DE 8. where cut or fill conditions are created, slopes would be varied rather than left at a constant angle which my be unstable or create an unnatural, rigid, "engineered" appearance. Figure 10 0 VAOMV& a* AR PYL6 swpw CI'o"ffs 20 euorM Am s, IM 9. The angle of any graded slope should be gradually adjusted to the angle of the natural terrain. Figure 11 -P)mt" AaMoANP,t it Ni4'rt/�L � � SRO �toOE' AWM6, OAOVAI~ N /YM- ter/s us COAMINS 1040#VS 7a A10AO- CiWWI-Y A9PW/AOM N/WM,4 MOM 10. Manufactured slopes adjacent to roadways shall be consistent with the Landform grading and rsvegetation technique to create visually interesting and pleasing streetscapes. Figure 12 �zr/s V*ift ' IN UVOSCA AAP WWAIr AW /,/ A17-1- tWis s7)VAA6yt SLOPS AWA:—#oW#pg M AOVnWr $P A*VAi4y 4 VAF440 section 110. MUM (See also Figure 6)_ 21 ADOP a UL s, IM Where a conflict exists between the provisions of this section and— Chapter 70 of the Uniform Building Code, the drainage, soils and geology provisions of this ordinance shall prevail, unless in the opinion of the City Engineer, the provisions of this section do not meet sound engineering standards. A. Standards 1. Debris basins, rip rap, and energy dissipating devices shall be provided where necessary to reduce erosion when grading is undertaken. Except for necessary flood control facilities, significant natural drainage courses shall be protected from grading activity. In instances where crossing is required, a natural crossing and bank protection shall be preferred over steel and concrete systems. Where brow ditches are required, they shall be naturalized with plant materials and native rocks. 2. Terrace drains where required shall follow landform slope configuration. Down drains shall not be placed in exposed positions. All down drains shall be- hidden in swales diagonally or curvilinear across a slope face. In this manner they will be built into the overall landform of the slope. (see Figure 13). Figure 13 0MAMPIVAMi.- 22 ADOFM h& J, IM SYS SMAa /50W6i/4V- AWp 1 AAW fP OF ywe16W.-Ow LAeovfie \\� 71TIMA OVAR*+f vN. VAIMArrr /.-V 3Lsv� AAVX A&S&'A49V,1A1O OMAN~ P:perLAM Aft oao Figure 14 /107` -1-#IG AW -Aft ft MaIAIF&Aw s nr VST V15/" a USF 6f A4P// D ASIC dr A""S AAeD UNPVOV RLQVS (INIf m" SLO*S 3. Building and grading permits shall not be issued for construction on any site without an approved location for disposal of runoff waters, including but not limited to such facilities as a drainage channel, public street or alley, or private drainage easement. 4. The use of cross lot drainage shall be subject to Planning Commission and City Council review and may be approved after demonstration that this method will not adversely affect the Proposed lots or adjacent properties, and that it is absolutely required in order to minimize the amount of grading which would result with conventional drainage practices. Mora cross lot drainage is utilized, the following shall apply: a• Project Interiors - one lot may drain across one other lot if an easement is provided within either an improved, open V-swale gutter, which has a naturalized appearance, or within a closed drainage pipe which shall be a ainiaum twelve (12) inches in diameter. In both oases, an integral wall, shall be constructed. This drainage shall be conveyed to either a public street or to a drainage easement. If drainage is conveyed to a private easement, it shall be maintained by 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. 23 ADOF D a& s, IM B. 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 determined on an individual basis and shall be dependent on appropriate hydrologic studies and access requirements. Figure 15 NArIvr /aq,4B /VW- , yrs GGyyG,�r* L/NFA I- where possible, drainage channels should be inconspicuous location, and more placed in receive a naturalising, treatment i importantly, they should colored concrete and landscaping, at native rock, appears as an int p �� so that the structure integral part of the environment. Figure 16 2. Natural drainage courses should be preserved and enhanced to 24 Aoon=Jw s, IM the extent possible. Rather than filling thea in, drainage features should be incorporated as an integral part of the Project design. Section 13. hooess, 'Trails a" Roadways ,• Standards. 1. 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. 2. Grooves for traction' shall be incorporated into the construction of driveways with a slope of twenty (20) percent or greater. 3. where retaininq walls are necessary adjacent to roadways or within street setbacks, they shall be 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 than three (3), three (3) foot high terraced or stepped retaining walls shall be utilized which are separated by a miniaom of three (3) feet and appropriate landscaping. Figure . 17 K 3p 4. Driveways shall enter public/private streets maintaining adequate line of sight. 5 • Local hillside strut standards shall be used to minimize grading and erosion potential while providing adequate access 25 ADWM h& S. iso 89 for vehicles, including emergency vehicles. 6. Grades of streets in the hillside areas shall be as provided' in this subsection. Hillside, collector and arterial streets shall not exceed 12 percent. Hillside residential local streets shall not exceed 15 percent. 7• Cul-de-sacs to a maximum of 1000 feet in length may be Permitted with a maximum of 30 dwelling units. $. All other street improvement standards shall conform to the standard plans and specifications for public streets of the City of Diamond Bar, 9• The Planning Commission or City Council may approve modifications to the above standards provided such modifications are in substantial conformance with the objectives stated in this section. guidelines. 1. Roadways and driveways, where feasible, should conform to the natural landform. They should not greatly alter the physical and visual character of a hillside by creating large notches in ridgelines or by defininq wide 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. Figure is i AVE ~NO AA&jt,,&WIC AOACS AiZWO AI, , z4d& 26 N4f' MV AND AW ANN AAs CCOAMAVA .7b . 9YWSP 4MAMS ADM= h& 3. 1993 Figure 19 NO ^VWVb SiIM Ar s/Aswzr— st off& AO AMOW AAWAO 454r 6 b so 1W ,044- -50rml AXVIA V aq , S44W S A ALMS 2. Where road construction is permitted in hillside areas, the extent of vegetation disturbance and visual disruption should be minimised by the combined use of retaining structures and regrading to approximate the natural slope. The following techniques should be used where feasible: a. Utilise landform .revegetation- planting in order to create a natural appearance and provide a sense of privacy. b. Reduce the visual and safety impacts by use of terraced retaining walls and landscaping. c. Split roadways increase the amount and appearance of landscaping and the median can be used to handle drainage. 27 ADOFM a& s, ism MIS 1 1 AZW AO 4r7' a,'t SA4W to Cti'WAV M Yn VW/C NA7►'WAiL C4WYzq^ AN AW /M". AOGWD Bfp- c r- S40%'g-,. AFAvw SCl4u. m2w gw AaV ^W c& * Cd~Aj AV iAW A Aj. Figure 20 //0 7Y7YS Wr C 0tft {I. c4 t- 54&W /AYW H144*Dif A44AWAY S Ver OW gMO4AW&,PAAAM RAK4%#V/No PyWpM �aaw�C � \ N% AY AOL" Afro C4- Qcvsa %ASO& �ovc to cHA�Ir,1r. �11dkN�7: 3. 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. 4. 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. 28 ADOMD UL s, IM A. Standards. 1. The dimensions of a buildinq 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. -/2V/S Fiqure 21 pA`MDo� fP//LA�NQ� aq�ygFahC,Y Plts /Mb yet bh7�!/VD �4 p M/N/K/zEs Ar -� N/�,tS/D�C US'E LCW 44/AL DEc'66 AMP S/DG DC'S. /VOf -hy/S M� s�yC AM VH/dy Pfd1�/L�r �W!w/iNNO aTAWS OW ay tHAt K/LG8/AW. AVOW ,P&40r6 fAMA10 hPCiW 7WO XAA- 'Y" S/DE. AWAMc✓N6 Meir' �f/1GO,yV6 M!'Ltiba ;*UFA� MQYs Ma1NvMEA/t�, �G11q� sVJ��1�A,IPd M4 /ilAq�t4► meet at iWA rye H. Guidelines 1. Design of building sites should be sensitive to the natural terrain. Structures should be located in such a way as to minimise necessary grading and to preserve natural features such as prominent knolls or ridgelines. 2. view of significant visual features as seen from both within and outside a hillside development should be preserved. The following provisions shall be taken into consideration: a. Dwellings should be oriented to allow view Opportunities, although such views may be limited. ROsideatial privacy should not be unreasonably sacrificed. b. Any significant public vista or view corridor as seen from a secondary, collector or major arterial should be 29 ADWM h& s. IM 3. Projects should incorporate variable setbacks, multiple orientations and other site planning techniques to preserve Open spaces, protect natural features and offer views to residents. THIS A. Standards. Figure 22 NOT 1 . The building envelope for all structures shall be as follows: a . Downh i 1 1-U& - A maximum/ height of thirty -f ive (3 5) feet as measured from natural or a finished grade at the front setback, extendinq towards the rear of the lot. The maximum height at the side setbacks shall be twenty- five (25) 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 or approved finished grade. Figure 23 AXW h*4 AAVtAW OV I 35' 5t�� Sl.�rl/i41�GYY 30 soorM h& S. IM Figure 24 LA01*0 ~ qM*" 700 MA*La is 7)w µ RAWA-- A"" AtRA OP*Wcv &P 44 6=49r 2. The building shall be terraced to follow the slope. 3. Architectural treatment shall be provided to all sides of the structure visible. 4. 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. 5. 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. B. Guidelines 1. The lora, mass and profile Of the individual buildings and architectural features should be designed to blend with the natural terrain and preserve the character and profile of the natural slope. Some techniques which may be considered include: a. Split pads, stepped footings and grade separations to PG=it structure to step up the natural slope. b. Detaching parts of a dwelling such as a garage. C. Avoid the use of gable ends on downhill elevations. The slope of the roof should be oriented in the same direction as the natural slope and should not exceed natural slope contour by twenty (20) percent. 31 ADM=Jm s, IM 2. Avoid excessive cantilevers on downhill elevations. 3. Excavate underground or utilize below grade rooms to reduce effective bulk and to provide energy efficient and environ- mentally desirable spaces. However, the visible area of the building shall be minimized through a combined use of regrading and landscaping techniques. 4. Use roofs on lower levels for the deck open space of upper levels. Figure 25 /-I//S OW OF A04 YVA44. Al4l0ft g AAV AW&W RACi t' AV sMGKL sc«4Gt /N✓. . Ai+r��1/� vP �Iil�/NA3 dla ���r " AIANVAft, VI&W. GAPA ' PO W040dWS AND AjF*VNA* AAL*M to tt1Q' raACOVD. NOt 7//S Alhowwr MW.%&M is YAW k"Imoi' /N awvmw 7'77 7WS k'IAL .+d.Aife. LAAair MfeaMr op eww 5. Building materials and color schemes should blend with the natural landscape of earth tones and natural chaparral vegetative growth. 6. To the extent possible, the width of'a building measured in the direction of .the slope, shall be minimised in order to limit the mount of cutting and filling and to better "fit" the house to the natural terrain. 32 ADWM h& s, tit Figure 26 t�Y/s NO�` tH/s 8�/LDy 6 �MUry QAV SOH W&" SGOAPS ASND A4V/N ON tHO 11/uqp& MINOL 6&IGWAO AA07"IAVO pp VW - IV M YW 7AC4Vft'TrI7j'V HIUSPR A. Standards &Y'a" /s ArAPOVDICUMA AV " C 1• Walls and fencing, not exceeding six (6) feet in height, visible from roadways or public rights-of-way shall be visually open and non-opaque. 2. Privacy walls and fences, not exceeding six (6) feet in height, are permitted adjacent to structures, in order to provide a private outdoor area. walls and fences shall be of materials and colors compatible with the structures facade. 3. Native or naturalized plants or other plant species that blend ed planting. with the l requirandscape shall be utilized in all areas with 4. Fire retardant plant materials shall be utilized. Plants selected as ground cover, shrubs or trees shall be from the list " approved by the City. S• A permanent landscape and irrigation system, for purposes of establishing and maintaining required planting, shall be installed on all slopes. The emphasis shall be toward using plant materials that will eventually now minimal irrigation. Water and energy conservation techniques shall be utilized including but not limited to such items as drip irrigation and use of "reclaimed water" and xeriscape. 33 ADOFTW h& S. IM Figure 27 r/ -//S Ivo �C"/jF BULK •� 1'' RMIKI i Ys ON6W PGAAMING A -P SWO"t- LOVArLC, Not 7A #9 NO P44Vf/NG oOssisca- AVB To IM a- AAX/N/NG I-Mt4. 1411 s AVD 7AOW 70 C9NC4fA-I- ,WIIH PL, "Wro AMD 6• 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. _ 7. Slopes with required planting shall be planted with informal clusters of trees and shrubs to gotten and vary the slope; plane. Where required by the City, jute netting shall be used to help stabilize planting and minimise soil erosion. 8. Native vegetation shall be retained and supplemented within undeveloped canyons and along natural drainage courses as allowed by state and federal resources agencies (State Department of Fish i Game, U. S. Fish and Wildlife, U. S. Army Corp. of Engineers). Figure 28 MIS .\ o � rev IANV fyys NAr►+141L �WI/�QAI�t eCAFAMIAA6 IiI1b4/N/Hi f$4WND tcain% VUl/K/i`lt�l1LK 7f,MlsrraNi4 cot gE'/J�1M'Res/6pY/NG ,89*4 ON NAYWAL. CAVOM ON AMP PAVL"7-e/Wp A04Pt W fN NO IPAM#bV^V. 34 ADOFM h& s, IM B. Guidelines 1. Natural landform. planting should be used to soften manufactured slopes,, reduce impact of development on steep Slopes or rudgelines, and p provide erosion control. 2. maintain a "vegetative backdrop" by replanting with approved trees. The vegetation should reduce the impact of the structures to the extent possible at maturity and preserve the appearance of the natural hillside. Figure 29 fi,. rrlA:At. &#IA o 4USy%pWV6 9. Use Landform. Grading to replicate the irregular shapes of natural slopes resulting in aesthetically pleasing elevations and profiles. Landform -graded slopes are characterised by continuous series of concave and convex forms interspersed with mou:Ws that blend into the profiles, non -linearity in plan view and varying slope gradients, and significant transition sons between man-made and natural slopes. Resultant pad configuration are irregular. 10. Slope down -drain devices shall be designed to either follow "natural" lines of the slopes or are tucked away in special Swale and berm combinations in order to conceal the drains from view. Exposed segments in high visibility areas are treated with natural rock. 11. Landscaping becomes a "revegetation" process and is applied in patterns that occur in nature: trees and shrubs are concentrated largely in concave areas, while convex portions are planted mainly with & s. 30 TJ IS , -') -% L- i 35 ADOFM ha s, IM Figure 31 S/- ORE 74HIs toE LMPFO." "V'Fr'~OA1. &VWOWo VOL CWLr POAL CoIKYik r"913 AW -SAIAVas C44WAFAM /A COMcAYrs AMEAS. 4„/y¢yAR s pFC/ArS Art 00"a". CoKYArA1rVN/i: LAND Vc 411fVW . rAws AND 9fpv8s SMOMP FOA vNIPV M coticA*Off. /of QHS r A. Fire Protection standards 1. All development shall be constructed in such a manner so as to reduce the potential for spread of brushfirs through consideration of the following:, a• In the case of a conflict where more restrictive provisions are contained in the Uniform Building Code or in the lire Code, the more restrictive provisions shall prevail. b. Roofs shall be covered with noncombustible materials as defined in the Building Code. Open save ends shall be stopped in. order to prevent bird nests or other combustible material lodging within the roof and to preclude entry of flames. C. Exterior walls shall be surfaced with noncombustible or fire resistant materials. -- d. Balconies, patio roofs, saves and other similar overhangs shall be of noncombustible construction or shall be protected by fire-resistant material pursuant to the Building Code. 36 ADOPM a.. s, IM 2. All development shall be constructed with adequate water supply and pressure for all proposed development in accordance with standards established by the Fire Marshal. 3• A permanent fuel modification area shall be required around development projects or portions thereof that are adjacent or exposed to hazardous •fire areas for the purpose of fire protection. The required width of the fuel modification area shall be based on applicable building and fire codes and a Fire Hazard Analysis Study developed by the Fire Marshal. 4. Fuel modification areas shall incorporate soil erosion and sediment control measures to alleviate permanent scarring and accelerated erosion. 5. If the Fire Marshal determines in any specific case that difficult terrain, danger of erosion or other unusual circumstances make strict compliance with the clearance of vegetation undesirable or. impractical, she/he may suspend enforcement thereof and require reasonable alternative measures designed to advance the purposes of this ordinance. 6. 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 sane to be done and make the expense of such correction a lien on the property upon which such conditions exist. 7. Require special construction features in the design of structures where site investigations confirm potential geologic hazards. section is. Proposed development within hillside areas shall require the submittal of a Conditional Use Permit application. Additional submittal requirements may include applications for Development Review, pals Tree Permits, Subdivision cad 2Wironnental Review. All applications shall incorporate the following filing requirements and shall include process fees as established by the City Fee Resolution. A. A natural features map, which shall identify all existing slope banks, r1d9Glines, canyons, natural drainage courses, federally recognised blue line streams, rock outcroppings, and existing vegetation. Also depicted shall be landslides and other existing geologic hasards. B. A conceptual grading plan, which shall include the following items in addition to those required by the Municipal Code or as part of the Submittal Requirement Checklist: 1. A legend with appropriate symbols which should include, but not be limited to, the following items: top of wall, top of curb, high point, low point, elevation of significant trees, spot elevations, pad and finished floor elevations, and 37 scop= h& s, IM change in direction of drainage. 2• A separate map with proposed till areas colored in green and cut areas colored in red, with areas where cut and fill exceed depths established in the hillside development guidelines and standards clearly shown. Additionally, the areas of cut and till, calculated as a percentage of the total site area, shall be included on the plan. .3. Contours shall be shown for existing and natural land conditions and proposed work. Existing contours shall be depicted with a dashed line with every fifth contour darker, and proposed contours shall be depicted as above except with a solid line. Countours shall be shown according to the following schedule: Natural Sloca ftylmui Znterva1Fee. Above 20% 5 C. A conceptual drainage and flood control facilities map describing planned drainage improvements. D. A Slope. Analysis map for the purpose of determining the amount and location of land as it exists in its natural state falling into each slope category as specified below. For the slope map, the applicant shall use a base topographical map of the subject site, Prepared and signed by a registered civil engineer or licenses land surveyor, which shall have a scale of not less -than 1 inch to 100 feet and a contour interval of not more than 2 feet provided that the contour interval may be 5 feet when the slope is more than 20 percent. This base topographical map shall include all adjoining properties within 150 feet of the site boundaries. Delineate slope bands in the range of to 10 percent, 10 up to 15 percent, 15 Up to 20 percent, 20 up to 25 percent, 25 up to 30 percent, 305 to 35; and 35 percent or greater. Also included shall be a tabulation of the land/area in each slope category specified in acres. B. Provide a sufficient number of slope profiles as required by the City 8ngineer to clearly illustrate the extent of the proposed grading. The slope profiles shall: 1. 8t drawn at the same scale and indexed, or keyed, to the grading plan, and project site map. 2. Show existing and proposed topography, structures, and infrastructures. Proposed topography, structures, and infrastructures shall be drawn with a solid, heavy line. Existing topography and features shall be drawn with a thin or dashed line. 3. The slope profile shall extend far enough from the project site boundary to clearly show impact on adjacent property, at least 150 feet. 38 Aoornsh& S, IM 4. The profiles shall be drawn along those locations of the project site where: (a) The greatest alteration of existing topography is proposed; and, (b) The most intense or bulky development is proposed; and, (e) The sits is most visible from surround land uses; and, (d) At all site boundaries illustrating maximum and minimum conditions. 5. At least two of the slope profiles shall be roughly parallel to each other and roughly perpendicular to existing contour lines. At least one other slope profile shall be roughly at a 45 degree angle to the other slope profiles and existing contour lines. F. The 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 profiles, and attestinq to the fact that the slope profiles have been accurately calculated and identified. G. The exact method for computing the percent slope and area of each Slops category should be sufficiently described and presented so that a review can be readily made. Also, a heavy, solid line indicating the grade differential shall be clearly marked on the plan, and an additional copy of the map shall be submitted with the slope percentage categories depicted in contrasting colors. H. 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. I. A statement of conditions for ultimate ownership and maintenance of all parts of the development including strests, structures and open spaces- In paces. In the event that no grading is proposed, i.e., custom lot subdivision, a statement to that effect shall be filed with a pian which shows possible future house plotting, lot grading, driveway design, and location for each parcel proposed, to be prepared on a topographic map drawn at the same scale as the conceptual grading plan. K. When unit development is proposed, illustrative building elevations, that shoe all sides of the proposed structures) and which accurately depict the building envelope for each lot, shall be provided. L. The following items may be required if determined necessary to aid in the analysis of the proposed project to illustrate existing or proposed conditions or both: 39 ADOMW A& s. IM 1. A computerized or 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. M. Exceptions to the filing requirements shall be determined by the Director and City Engineer. a wrnmouut&MYNNESAW 40 eoorrsn h& 5.,1"3