To use to the fullest, current practices of good civic design, architecture, landscape architecture, civil engineering and hillside land planning to preserve, enhance and promote the existing and future appearance and resources of hillside areas.

To encourage in hillsides alternative approaches to conventional flat land development practices.

To encourage the planning, design and development of home sites that provide maximum safety with respect to fire hazards, exposure to geological and geotechnic hazards, drainage, erosion and siltation, and materials of construction; and provide the best use of natural terrain.

To require the retention of significant natural landforms, vegetation and landmarks.

To provide a safe means of ingress/egress for vehicular and pedestrian traffic to and within hillside areas, with minimum disturbance to the natural terrain.

To require that utilities be placed underground.

To encourage single-family house designs that fit the landform rather than adjusting the landform to fit the house.

Single-family residential units;

Watershed and flood-control facilities;

Grazing;

Public parks and open areas;

Public and private trails.

Home occupations, per the provisions of Section 18.184.010;

Household pets as described and regulated in Chapter 18.20 Residential Zones Generally.

When designated SF-H, the yield is Y = 1.5 -.03S.

When designated SF-Hb, the yield is Y = .45 -.0081S.

"N" is the maximum number of lots in any subdivision; and

"A" is the gross developable area of the total parcel in acres inclusive of public utility easements or rights-of-way, park land dedications or other public easements or dedications existing or required for the subdivision. The number of lots determined by the above formula shall be rounded down to the next whole number.

For all subdivisions with an average slope of less than twenty percent, the minimum net lot area shall be twenty-five thousand square feet.

For all subdivisions with an average slope of twenty percent or more, the minimum net lot area shall be one acre (forty-three thousand five hundred sixty square feet).

For all subdivisions with an average slope in excess of forty-eight percent, the minimum net lot area shall be twenty acres. It is anticipated that residential subdivisions will not normally be undertaken in such areas. If residential development of such areas is undertaken, the lots may have to be considerably larger to allow the development of homesites and roads meetings standards of this chapter. Actual lot size shall be determined as approved by the planning commission and city council in accordance with the grading and roadway standards of this chapter based on the development plans required by this chapter.

"S" is the average slope in percent;

"I" is the contour interval in feet;

"L" is the combined length of contour lines in scale feet within the parcel; and

"A" is the area in acres of the parcel to be subdivided.

All graded slopes are to be contoured and blended to harmonize with natural slopes.

Housing is to be designed to fit the natural landform in a manner that does not require extensive grading, through split-level house designs and other similar techniques.

Significant landmark features as determined by the planning commission and the city council, such as natural rock outcroppings, prominent trees and other areas of special natural beauty, shall be preserved.

Maximum vertical height of cuts, exposed or retained by walls, from toe to top, should not exceed twelve feet.

Maximum vertical height of fills, exposed or retained by walls, from toe to top, should not exceed twelve feet.

The maximum steepness of exposed cuts and fills shall not exceed 2:1, and preferably 3:1 for fills.

Maximum heights for cuts and fills may be exceeded only on "difficult lots" and when a plan for grading and planting has been prepared in conjunction with a licensed landscape architect. Such plans shall be presented to the planning commission for review and approval.

Building sites shall not be pregraded until specific house site plans and elevations have been approved for the individual site.

No curb cuts shall be provided until specific house site plans have been approved for the individual site.

All improvements located within the slope areas, such as landscaping and sprinklers, shall be maintained in a safe condition and a state of good repair.

The declaration may provide for termination of the covenants, conditions and restrictions at the expiration of the economic life of the project with the consent of the city council.

Proposed site plans and conceptual house elevations.

Proposed grading plans.

Cross-sections and profiles thereof (where required by the city planning or engineering department).

Conceptual site plans and conceptual house elevations.

Conceptual landscape plans.

Data describing the existing vegetation, topography, soils, geologic, seismic and drainage conditions at the proposed site.

Detailed studies and analyses which may be provided as part of the environmental assessment form and/or impact report, if required, prepared in accordance with adopted city guidelines.

When required by the planning director, the applicant shall submit a scaled, profile model depicting any or all portions of the site proposed for development. The model shall have a 2:1 vertical scale to give proper perspective of site conditions.

Setbacks. Distances of structures to the property line may be varied, as long as the distance between structures on adjoining parcels are not reduced below the distance otherwise accomplished through standards in this district.

Minimum Lot Size. Lot size may be reduced to no less than twenty thousand square feet.

Lot Width. Lot width may be reduced to no less than one hundred feet.

Slope Areas. All cut or fill slopes less than five feet in vertical height shall be planted with adequate plant materials to protect the slope against erosion. Plant material shall be selected from the list of plant materials in this chapter. The planting shall be in the ratio of at least one tree per three hundred square feet and one shrub per one hundred fifty square feet of actual slope area and with ground cover to completely cover the bank within two years from the time of planting. An automatic sprinkler or drip irrigation system shall be installed to irrigate the slopes.

General Conditions.

To provide for a safe means for ingress and egress of vehicular and pedestrian traffic to and within the hillside areas and to provide for access of emergency vehicles necessary to serve the hillside areas.

To encourage developments which will result in preservation of the natural character of the hillside and the amenities provided by the hillside areas.

To reduce the scarring effects of hillside street construction while maintaining an acceptable level of safety against unstable slopes or slopes subject to erosion and deterioration.

To provide for the most economical construction of the necessary streets within the hillside areas consistent with the objectives enumerated above.

Curbs. Vertical curbs of Portland cement concrete six inches in height shall be constructed on both sides of all public streets. Curbs which serve to carry storm runoff shall be constructed with an integral Portland cement concrete gutter. Exceptions to this requirement may be permitted where the planning commission finds that adequate drainage and traffic control are provided and normal maintenance would not be impaired.

Parking Lanes. Parking lanes, eight feet in width, shall be provided on at least one side of all public streets except where existing topography renders development adjacent to the street impractical; or where off-street parking spaces are provided on each lot adjacent to the street or in parking bays. Roads without parking lanes shall be provided with emergency parking stalls adequate to contain two vehicles and spaced at an average distance of five hundred feet.

Horizontal and Vertical Curves. The design of all streets shall incorporate horizontal and vertical curves adequate to provide safe vehicular travel. The minimum horizontal curve radius on residential streets shall be one hundred feet and the minimum length of vertical curve shall be one hundred feet where practicable. Collector streets and thoroughfares shall be designed to incorporate vertical and horizontal curves greater than the said minimum for residential streets in order to provide for increased traffic flow and vehicle speeds on such collector streets and thoroughfares. The paved width of one-way streets shall be increased as necessary to provide for safe movement of traffic at sharp curves.

Cut and Fill Slopes. All manufactured slopes adjacent to the roadway shall normally be a maximum of two horizontal to one vertical unless limited by existing topography or constructed in rock. Manufactured slopes of less than two to one may be permitted where adequate slope control measures such as retaining walls or rip-rap embankment are utilized. The slope shall in no case exceed the natural angle of repose of the material. Cut and fill slopes shall be constructed to eliminate sharp angles of intersection with the existing terrain and shall be rounded and contoured as necessary to blend with the natural topography to the maximum possible extent.

Erosion Control. All manufactured slopes, other than those constructed in rock, shall be planted or otherwise protected from the effects of storm runoff erosion and shall be benched or terraced as required to provide for adequate stability. Planting shall be designed to blend the slope with the surrounding terrain and development. Manufactured slopes in rock shall be provided with soil pockets to contain landscaping where appropriate. Irrigation facilities shall be required where necessary to provide for proper maintenance of the planted areas.

Storm Drainage. The design of storm drainage facilities shall insure the acceptance and disposal of storm runoff without damage to the street or to adjacent properties. The use of special structures to accept design storm runoff shall be incorporated into the street design where appropriate.

Walkways. Walkways of four feet minimum width shall be provided along or in the proximity of all public streets, and along private streets as determined by the planning commission to be necessary. Walkways shall be constructed of materials suitable for use in the particular area and shall be located as necessary to provide a maximum of pedestrian safety and a maximum use of the character of the hill area. Materials utilized for walkway construction shall not result in an abnormal maintenance expense to the taxpayers.

Geometrics.

Construction Standards. All streets shall be constructed so as to carry the anticipated traffic load without deterioration over the design life of the roadway. Streets constructed on a gradient of eighteen percent or less shall be paved with asphalt concrete placed over a suitable base course. Streets constructed on a gradient in excess of eighteen percent shall consist of a Portland cement concrete surfacing with a minimum thickness of six inches placed on a suitable base course and shall be provided with a roughened surface to minimize skidding or slipping of vehicles.

Street Lighting. All hillside public streets shall be provided with a level of street lighting designed to protect the health, safety and welfare of those living within the hillside areas. Street lights shall be mounted on ornamental electroliers.

Driveways and Drives. Driveways and drives shall be designed to a grade and alignment that will provide the maximum of safety and convenience for vehicular, emergency and pedestrian use and in a manner which will not interfere with drainage or public use of the sidewalk and/or street area.

Thoroughfares. The design of thoroughfares of four lanes or more within the hill areas shall conform to the principles hereinbefore enumerated.

Private Streets. The use of private streets or lanes within hill area developments shall be encouraged where such streets will create a more desirable living environment and result in a more desirable utilization of the amenities of hillside topography. Such streets or lanes shall have a minimum paved width of twelve feet when serving less than three lots, a minimum paved width of sixteen feet when serving three to five lots, and a minimum paved width of twenty-four feet when serving six or more lots. Any streets in excess of one hundred feet in length shall be a minimum width of twenty feet. Provisions shall be made for maintenance of private streets to the satisfaction of the planning commission and city council.