CHAPTER 2
ZONING
ARTICLE 11. REGULATIONS IN HILLSIDE (-H) DISTRICT
SECTION:
§9136: Yard And Building Site Requirements In Designated -H Districts
§9138: Exceptions To Front Setback Lines
§9139: Hillside Development Standards
§9135 PURPOSE AND INTENT
A hillside (-H) district may be combined with any district or portion of a district defined in this chapter. The regulations contained in this article, and the regulations governing any district which is combined with a hillside (-H) district where not inconsistent with the regulations set forth in this article, shall apply in the hillside (-H) district. The purpose of this section is to implement the hillside designation of the general plan and provide site standards to promote fire and geologic safety and aesthetic qualities. The intent of this district is to:
A. Encourage concentration of dwellings and other structures by clustering and/or high rise to help save larger areas of open space and preserve the natural terrain;
B. Encourage the planning, design, and development of building sites in such a fashion as to provide the maximum in safety and human enjoyment while adapting development to, and taking advantage of, the best use of the natural terrain;
C. Prohibit, insofar as is feasible and reasonable, padding or filling of building sites in the hillside areas;
D. Ensure underground installation of utility wires and television lines;
E. Preserve outstanding natural physical features, such as the highest crest of a hill, natural rock outcroppings, major tree belts, etc.;
F. Minimize grading and cut and fill operations consistent with the retention of the natural character of hill areas;
G. Minimize the water runoff and soil erosion problems incurred in adjustment of the terrain to meet on site and off site development needs;
H. Achieve land use densities that are in keeping with the general plan; densities will decrease as the slope of the terrain increases in order to retain the significant natural feature of the hill areas. (Ord. 1125, §1, adopted 2010)
§9135.5 DEFINITIONS
For the purpose of this article, the phrases and terms herein shall have the following meanings:
AVERAGE PARCEL SLOPE: Average slope shall be determined by the formula:
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S |
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I x L x .00229 |
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A |
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In which: |
S |
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Average slope |
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I |
= |
Contour interval in feet |
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L |
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Combined length in feet of all contours on the parcel |
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A |
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Parcel in acres |
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DEFENSIBLE SPACE: As defined by the state of California department of forestry and fire protection.
GRADING: Excavation or fill of material, including the conditions resulting therefrom.
NATURAL GRADE: The natural contour of the land as it existed prior to human disturbance, such as grading, filling, or excavation; or where the natural grade has been modified, the grade existing on the effective date of the first hillside ordinance.
NATURAL STATE: Land in natural or undisturbed or unaltered state, including maintenance of natural grades, drainage patterns, rock outcroppings, and native trees and vegetation, excluding vegetation modification required by the state of California department of forestry and fire protection for defensible space unless the native vegetation in these areas is maintained and the vegetation planted is native or in the case of the area defined as defensible space by the state of California department of forestry and fire protection planted consistent with landscaping standards for defensible space. The intent is to retain the maximum amount of native vegetation and landscaping feasible while meeting fire protection requirements. (Ord. 1125, §1, adopted 2010)
§9135.6 MAINTENANCE
Maintenance is allowed on developed and undeveloped parcels that includes, but is not limited to, the following:
A. Maintenance of fire breaks when the natural grade is maintained;
B. Maintenance of fire access/roads when the natural grade is maintained;
C. Cutting/removal of weeds, grasses, and shrubs;
D. Pruning/removal of nonnative trees; and/or
E. Pruning/trimming of native trees.
The above types of maintenance may exceed the minimum amount of defensible space required by the state of California department of forestry and fire protection. (Ord. 1125, §1, adopted 2010)
§9136 YARD AND BUILDING SITE REQUIREMENTS IN DESIGNATED -H DISTRICTS
(Rep. by Ord. 1125, §1, adopted 2010)
§9137 FRONT SETBACK LINES
In the hillside (-H) district, no building construction shall be permitted or allowed at any distance closer to the street right of way line along any adjacent street than the distances set forth in subsection 9139A2 of this article for minimum front yards. Corner lots shall be considered as having a front setback on both adjacent street frontages. (Ord. 1125, §1, adopted 2010)
§9138 EXCEPTIONS TO FRONT SETBACK LINES
The exceptions to the front setback requirement set forth in section 9020 of this chapter shall not apply in the -H district. (Ord. 1125, §1, adopted 2010)
§9139 HILLSIDE DEVELOPMENT STANDARDS
Any parcel of land or subdivision having an average ground gradient across any portion of the property in excess of fifteen percent (15%) shall require a use permit for development. Specific criteria for density, circulation and lot requirements shall be determined on an individual basis utilizing geologic and soils reports, vegetation surveys and aesthetic evaluation. Minimum lot size in this zone shall be ten thousand (10,000) square feet.
A. Minimum Site And Development Standards:
1. Lot Size: Lot size, retention of land in natural state based upon average parcel slope.
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Development Standards |
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Average Parcel Slope |
Minimum Lot Size |
Minimum Percent Of Property To Be Retained In Natural State |
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15% to 20% |
10,000 sq. ft. |
40 |
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Greater than 20% to 25% |
20,000 sq. ft. |
50 |
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Greater than 25% to 30% |
1 acre |
75 |
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Greater than 30% to 50% |
5 acres |
85 |
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Greater than 50% |
10 acres |
Maximum amount possible in order to allow 1 dwelling unit and associated improvements (road, driveway, utilities) needed to serve the dwelling and comply with state of California department of forestry and fire protection requirements. Accessory dwellings are prohibited. Use permit process will determine the location of the dwelling and associated improvements |
a. Calculating Natural State: The minimum amount of the parcel to be retained in natural state shall be based on the gross area of the parcel and calculated by multiplying the gross area of the parcel by the minimum percentage to be retained in natural state, except as allowed by the following:
(1) When previously graded or disturbed areas (such as road, driveway, grading, building site) existing prior to the adoption of the first hillside ordinance are used as part of the proposed development or redevelopment of the site, they shall be included in the gross square footage of the parcel used to calculate the minimum percentage of the parcel required to be retained in natural state. This section shall apply when the project results in the reuse of an area(s) previously graded or disturbed.
(2) When previously graded or disturbed areas (such as road, driveway, building site) existing prior to the adoption of the first hillside ordinance are not used as part of the development or redevelopment of the site, they shall not be included in the gross square footage of the parcel used to calculate the minimum percentage of the parcel required to be retained in natural state. This section shall apply when the project results in an increase in the grading/disturbance of the parcel.
(3) Additional areas that are blended and/or contoured as part of the development proposal in order to simulate the natural grade and/or contour of the site prior to the development and are planted with native vegetation, or in the case of areas required to be maintained as defensible space by the state of California department of forestry and fire protection consistent with the DOF landscaping requirements for defensible space may also be included as natural state when approved by the decision making authority as part of their review of a discretionary application.
Plans shall be submitted as part of the discretionary application that demonstrate how the grade/contour will approximate the natural state, how this will be accomplished, and the trees and vegetation that will be planted.
2. Setbacks: Minimum thirty feet (30’) from all property lines, and thirty feet (30’) from ridge top or toe of slope for gradient in excess of fifteen percent (15%).
3. Disclosure: Property purchase/sale transaction shall include full disclosure of fact that property is within fire hazard area.
4. Building Material: No combustible roof material as determined by the fire marshal and the building official shall be used on buildings in this zone.
5. Water Supply And Fire Hydrants: The following shall be required:
a. Slopes of twenty percent (20%) and less: Two (2) hours supply with fire flow capability of seven hundred fifty (750) gallons per minute at twenty (20) psi. Fire hydrants maximum three hundred thirty feet (330’) apart with six inch (6") main line.
b. Slopes in excess of twenty percent (20%): Two (2) hour supply with fire flow capability of five hundred (500) gallons per minute at twenty (20) psi. Fire hydrants maximum six hundred sixty feet (660’) apart with six inch (6") main line.
6. Subdivisions: In subdivision developments with full width city streets, proposed firebreaks or other separations from wildland areas may have other requirements based upon specific design.
B. Use Permit Procedure: Prior to any construction or grading in this district, a use permit shall be approved by the planning commission.
Additional information or data may be required as determined necessary by the director of planning. The following reports shall be required with each application.
C. Soil Reports:
1. A soils engineering report shall include data regarding the nature, distribution and strength of existing soils, conclusions and recommendations for grading procedures, design criteria for corrective measures and opinions and recommendations covering the adequacy of sites to be developed.
2. The investigation and subsequent report shall be completed by a professional engineer registered in the state of California, and experienced and knowledgeable in the practice of soils mechanics.
3. Recommendations included in the report and approved by the engineer shall be incorporated into the design plan or specifications.
4. Any area which presents one or more of the following limiting factors shall not be subjected to development unless the engineer can demonstrate conclusively to the commission that these limitations can be overcome in such a manner as to prevent hazard to life, hazard to property, adverse effects on the safety, use or stability of a public way or drainage channel and adverse impact on the natural environment.
a. Water table within six feet (6’) of the surface at any time of the year.
b. Soils with a high shrink-swell potential.
c. Soils with a unified classification of unstable soil types.
D. Geology Reports:
1. A geology report shall include a description of the geology of the site, conclusions and recommendations regarding the effect of geologic conditions on the proposed development, and opinions and recommendations covering the adequacy of sites to be developed.
2. The investigation and subsequent report shall be completed by a professional geologist registered in the state of California and experienced and knowledgeable in the practice of engineering geology.
3. Any area which the investigation indicates has geological hazards shall not be subjected to development unless the geologist can demonstrate conclusively to the commission that these hazards can be overcome in such a manner as to prevent hazard to life or limb, hazard to property, adverse effects on the safety, use or stability of a public way or drainage channel, and adverse impact on the natural environment.
E. Subsurface Investigations: For both soil and geologic reports, subsurface investigation shall be performed throughout the area to sufficiently describe the existing conditions.
In particular, subsurface investigations shall be conducted where stability will be lessened by proposed grading or filling or where any of the following conditions are discovered or proposed:
1. Fault zones, where past land movement is evidenced by the presence of a fault gorge;
2. Contact zones between two (2) or more geologic formations;
3. Zones of trapped water or high water table;
4. Bodies of intrusive materials;
5. Historic landslides or where the topography is indicative of prehistoric landslides;
6. Adversely sloped bedding plains, short range folding, overturned folds and other geologic formations of similar importance;
7. Locations where a fill slope is to be placed above a cut slope;
8. Proposed cuts exceeding twenty feet (20’) in height, unless in extremely competent rock;
9. Locations of proposed fills exceeding twenty feet (20’) in height;
10. Where side hill fills are to be placed on existing slopes steeper than sixteen percent (16%);
11. Wherever groundwater from either the grading project or adjoining properties is likely to substantially reduce the subsurface stability.
F. Hydrology Report:
1. A hydrology report shall include a description of the hydrology of the site, conclusions and recommendations regarding the effect of hydrologic conditions on the proposed development, and opinions and recommendations covering the adequacy of sites to be developed.
2. The investigation and subsequent report shall be completed by a qualified registered professional, experienced and knowledgeable in the science of hydrology and in the techniques of hydrologic investigation.
3. Any area which the investigation indicates has hydrological hazards shall not be subject to development unless the professional can demonstrate conclusively to the commission that these hazards can be overcome in such a manner as to prevent hazard to life or limb, hazard to property, adverse effects on the safety, use or stability of a public way or drainage channel, and adverse impact on the natural environment.
4. Flood frequency curves shall be provided for the area proposed for development.
G. Vegetation Report:
1. A vegetation report shall include a description of the vegetation environment of the site (species, height, size, general condition, location), conclusions and recommendations regarding the effect of proposed development on the site’s vegetation, and opinions and recommendations covering the adequacy of sites to be developed.
2. The investigation and subsequent report shall be completed by a qualified registered professional, experienced and knowledgeable in the science of botany and in the techniques of vegetation investigation.
3. Any area which the investigation indicates has rare or endangered flora species shall not be subjected to development unless the professional can demonstrate conclusively to the commission that these can be mitigated.
H. Structure Elevations: Views of all sides of proposed structures and perspectives of the proposed development from two (2) different angles.
I. Grading Plan: The grading plan shall include information concerning the existing physical characteristics of the area as well as data on anticipated changes as a result of the grading operation. It will also include a description of the grading process itself which will note times and exact location of proposed earthmoving activities. The plan shall include:
1. An accurate plot plan showing buildings, roads, utilities or other improvements within the area and adjacent thereto.
2. A map drawn to a scale approved by the planning department showing accurate contours at two foot (2’) intervals of the topography of the property and the area adjacent within fifteen feet (15’). Elevations to be based on USGS data.
3. Cross section showing both the original and proposed ground surfaces, with grades, slopes and elevation noted.
4. Detailed plans of all drainage devices, walls, cribbing, dams or other protective devices to be constructed in connection or as part of the proposed work.
5. A map showing the drainage area and estimated runoff of the area served by any drains and proposed methods of runoff disposal.
6. A soil stabilization report including final ground cover, landscaping and erosion control measures to prevent soil loss when the grading is in process.
7. A description of equipment and methods to be employed in processing and disposing of soil and other material that is removed from the grading site, including the location of disposal sites.
8. A schedule showing when each stage of the project will be completed, including estimated starting and completion dates, hours of operation and days of week of operation.
9. Specifications controlling construction methods and materials in construction of the work, including:
a. Provisions for control of grading operations within the construction area and on public roads.
b. Safety precautions to be observed and facilities to be provided.
c. Compliance with laws and local regulations.
d. Control of dust.
e. Other related matters. (Ord. 1125, §1, adopted 2010)