Chapter 9-50 — HILLSIDE DEVELOPMENT STANDARDS AND GUIDELINES

The purpose of this chapter is to provide standards and guidelines for hillside development. (Prior code § 9-29.010; Ord. 98-8 § 2 (part))

These regulations shall apply to all property within the city having a slope gradient, whether natural or manufactured, of fifteen (15) percent or greater. (Prior code § 9-29.020; Ord. 98-8 § 2 (part))

Development shall not occur upon any lot subject to these standards and guidelines until all appropriate land use and building permits shall have been issued by the city. Referenced standards and limitations shall apply to new construction, expansions of use, or modification of existing uses equal to or greater than twenty-five (25) percent of the building gross floor area or ten percent of the lot area, whichever shall be more restrictive. (Prior code § 9-29.030; Ord. 98-8 § 2 (part))

The Community Development Director and City Engineer will prepare and maintain a manual which contains design standards for hillside properties. The manual shall serve as the basis for determining project compliance with this chapter.

The manual shall contain narrative and graphic explanations of required design standards. The manual shall be available to assist property owners in their design of improvements. As a minimum, the manual shall address the following:

• A. Setbacks;

• B. Structure heights;

• C. Access;

• D. Grading;

• E. Drainage;

• F. Siting considerations;

• G. Geotechnical requirements.

(Prior code § 9-29.040; Ord. 98-8 § 2 (part))

• A. Site Design Principles.

  1. Most of the hillside sites are highly visible from distant locations. Therefore, views of the site from the neighborhood and other off-site locations should be given careful consideration.

  2. Massive grading and single retaining walls in excess of six feet in height are to be avoided in order to preserve a more natural slope appearance.

  3. The buildings located near hillside rims have higher visibility. The buildings should be partially screened with landscaping to minimize the “wall” effect.

  4. Significant trees and other vegetation, which contribute to the aesthetics of the site and surrounding area, should be preserved.

• B. Hillside Grading and Drainage.

  1. Retaining walls visible from off-site should be of reduced height.

  2. Drainage devices, such as terrace drains, benches and downdrains, should be located underground or placed in locations of least visibility on slopes. The downhill side of a drain should be bermed to conceal it. Natural swales leading downhill are good locations for down drains. Any visible drains should be as close as possible to natural soil color. Visible concrete drains should be color tinted and screened with planting.

• C. Planting Design for Hillsides.

  1. Common open space and landscaped areas maintained by homeowners’ associations are subject to review under these guidelines. The provisions of these guidelines are recommended for planting in single-family, duplex, and multi-family hillside residential developments.

  2. Plant Selection.

  • a. The plant materials should be selected for erosion control effectiveness, fire resistance, drought tolerance, and ability to enhance the color and texture of the surrounding landscape.

  • b. The location and heights of plantings should follow the downhill alignments of taller trees.

  • c. Use less dense, open trees that do not block views.

3. Planting Techniques for Graded Slopes.

   • a. The irregular spacing of vegetation is encouraged to achieve a natural appearance on graded slopes. The inclusion of shrubs that vary in height between tree stands will provide aesthetic diversity.

   • b. Whenever possible, trees should be located in swale areas to more closely reflect natural conditions and gather surface runoff for plant irrigation.

4. Transitional Slope Plantings.

   • a. Transitional slope plantings should be used between the domestic plantings and the native, flammable brush of undisturbed areas. The goal is to reduce the rate of approaching fire within the transitional zone by reducing the fire’s fuel supply.

   • b. Transition areas can be divided into three planting zones, subject to city approval. This could include the following:

Zone #1: Ornamental non-native fire retardant species.

Zone #2: Native vegetation which should be selectively pruned and thinned with introduced fire retardant plantings. Plants with high fuel volume should not be used in this zone.

Zone #3: Native vegetation which should be selectively pruned and thinned. Plants with high fuel volume are discouraged in this zone.

(Prior code § 9-29.050; Ord. 98-8 § 2 (part))

The property owner, his or her designated representative or agent shall complete and submit the required site development permit application and shall obtain a decision on the application prior to instituting any work. Application shall be made upon the forms and in the format provided by the Planning Department and shall be accompanied by a fee as established by resolution of the City Council for the application. Modifications to a required site development permit shall be subject to the same requirements as the original.

A site development permit shall be required whenever the following circumstances occur:

• A. The proposed project requires the movement of five hundred (500) cubic yards or more of earth and involves slopes of fifteen (15) percent or more;

• B. The proposed project requires movement of five thousand (5,000) cubic yards of earth regardless of slope;

• C. When, in the discretion of the Community Development Director and City Engineer, the combination of earth movement and slope gradient may result in unstable conditions, aesthetic degradation, or potential damage to abutting uses.

(Prior code § 9-29.060; Ord. 98-8 § 2 (part))