50.0 and over (No grading except as provided expressly in this chapter)

b.

The "average slope" of a parcel of land or any portion thereof shall be computed by applying the following formula to the natural slope of the land, before any grading is commenced. For the purpose of establishing density yield for any given parcel as referenced in subsection C of this section, the formula comprising Appendix A, entitled Slope Density Chart, shall be applied to the entire parcel being considered for development. For the purpose of determining which areas of the site may be graded, the following formula shall be applied only to those portions of the site with less than a fifty-percent slope.

S = 0.00229 IL A

Where: S = Average percent slope

I = Contour interval, in feet

L = Summation of length of all contours, in fee

A = Area of land being considered, in acres

c.

"Natural slope" means areas which have not been previously significantly graded, or where there is no landslide activity.

E.

Potential Hazard Areas. No building or structure shall be located on property which is within any area described on the map referred to in Section 18.14.020 as a "potential hazard area," unless a competent geologic report unequivocally shows that the proposed placement of the specific buildings and/or structures can be safely accomplished.

F.

Natural Features. Each applicant submitting the plan shall specifically describe thereon all of the property proposed for development which is included within a "major ridge line," or within a "major flora and fauna area." The delineation shall be based upon the designation of such "major ridge lines" and/or "major flora and fauna areas," as referred to in the map referenced in Section 18.14.020. No building or structure shall be located, constructed or maintained on any property designated as the site of a "major ridge line," or a "major flora and fauna area" on an approved plan, except that streets, ways and emergency vehicular access routes may, if necessary for primary access to developable areas, be located thereon so long as the city council finds that the location of any such facilities will not cause biological damage to those areas, or any other area necessary to the continued survival of plant and animal population in those areas.

Those areas shown as "moderate sensitivity" on the map referred to in Section 18.14.020, labeled as "biological sensitivity," shall be given special consideration so as to retain these areas to the maximum extent possible. Consideration shall be given and findings made as to the relationship between all biological and wildlife corridor areas, major ridge lines, and the proposed development during approval of a plan.

Since it is required that even ridge lines not specified as major ridge lines in this subsection may be aesthetically important and warrant protection, specific development guidelines for all such ridge lines shall be formulated at the hillside-plan level of development based upon the specific ridge line and the type and extent of individual development.

With respect to hillside areas proposed for development in the future, and for which major ridge lines and major flora and fauna areas have not yet been designated, the planning commission and city council shall utilize criteria for making such designations which afford environmental protection to at least the same extent as that now provided in areas for which such designations are made in this subsection.

G.

Fire Protection. Because all of the properties classified within the H-R zone are in areas designated as high fire-risk areas, the following fire protection measures shall be observed and maintained for each dwelling unit:

Each habitable structure shall be provided with fire-retardant roof covering consistent with the provisions of the city's building regulations; and

Around each habitable structure, there shall be an area cleared of native brush to a minimum twenty-foot radius from the structure. Such area shall be replanted with perennial grasses or other fire-resistant plants or ground cover and continually maintained, and shall be provided with automatic sprinkler systems; and

As determined by the fire chief, all brush shall be removed and cleared within twenty feet of each side of every roadway. This includes all flammable vegetation or other combustible growth. This provision shall not apply, however, to single specimen trees, ornamental shrubbery, and cultivated ground cover, such as grass, ivy, succulents, or other similar plants used as ground cover, provided they do not form a means of readily transmitting fire.

H.

Erosion Control. To prevent damage by reason of erosion of land, the following standards shall be observed in all H-R zones:

All manufactured slopes shall be planted or otherwise protected from the effects of storm- runoff erosion, in a manner approved by the director of parks, within thirty days of the completion of the grading. Planting shall be designed to blend the slope in with the surrounding terrain and development; and

Permanent irrigation systems shall be provided to insure the proper maintenance of the planted areas; and

Each plan shall provide a suitable method for insuring compliance with landscaping and irrigation plans, which shall be approved as a part of such plan for all manufactured slopes and recreation areas.

I.

Off-Street Parking. Each residential unit located within the H-R zone shall be provided, permanently, with two off-street parking spaces, constructed and maintained in accordance with the parking development standards set forth in Chapter