This section defines applicable site and building development guidelines.
A. Site Plan And Building Design:
1. Areas disturbed by grading (e.g., cut and fill) shall be kept to a minimum.
2. Development shall be concentrated on slopes less than fifteen percent (15%) on the site, with slopes of greater than fifteen percent (15%) remaining undisturbed to the extent possible. Maximum disturbance of the site development area shall be as set out in table 17.05.140 of this section.
3. Whenever possible, structures shall be located on the natural slope of the land or on previously disturbed areas, rather than manmade pads or terraces.
4. Development shall be clustered to preserve existing topographic features and vegetative cover.
5. All building permit applications for structures on lots with a natural slope of fifteen percent (15%) or greater shall be accompanied by a geotechnical assessment. Building locations should be designed to address identified hazards, minimize runoff and erosion, and utilize the existing slope. Special types of building construction, such as split pad and stepped foundations, shall be used to minimize site disturbance and ensure that development conforms to the land.
6. Native vegetation shall be retained to the extent possible, even in identified setback areas, except where required to provide a defensible space to minimize threat of wildfires.
7. Use of reflective building materials shall be avoided.
8. Where retaining walls or other structures are used to stabilize cuts or fills, their design should follow the natural contours of the slope. Plans for proposed retaining walls or structures greater than four feet (4') in height shall be accompanied by engineered drawings meeting adopted building codes. Multiple wall groupings shall have at least equal lateral run to vertical rise.
B. Site Disturbance And Density Standards:
1. Projects On Steeply Sloped Lands: Projects on steeply sloped lands shall have limited density and site disturbance based on the existing topographical slope for the site or any portion of a site according to the standards listed in table 17.05.140 of this section.
DENSITY AND DISTURBANCE STANDARDS
Slope Class (Percent) | Maximum Percent Of Density Permitted | Maximum Percent Of Site Disturbance1 | Maximum Percent Of Impervious Surface |
0.0 to 14.9 | 100 | n/a | As allowed by underlying zoning district standards |
15.0 to 24.9 | 50 | 50 | 25 |
25.0 to 34.9 | 25 | 25 | 10 |
35.0 and over | 10 | 10 | 10 |
Note:
1. “Maximum percent of site disturbance” means the total disturbed area of alteration to the ground of the entire lot or parcel resulting from temporary and permanent construction activities. The remaining area shall be designated as “not to be disturbed” and identified on the plat.
2. Clustering: The net density allowed by the underlying zoning district for areas having slopes greater than fifteen percent (15%) which remain undeveloped may be transferred to other areas of the development site if clustering concepts are used and the project retains acceptable (see subsection B5 of this section) open space.
3. Minimum Lot Sizes: Minimum lot sizes may be waived by up to fifty percent (50%) and building sites may be clustered if thirty percent (30%) or more of the site is maintained as acceptable open space (see subsection B5 of this section). If the development contains individual lots, all required setbacks must be maintained.
4. Density Bonuses: A density bonus of five percent (5%) shall be awarded for every ten percent (10%) of the property which is dedicated (i.e., if maximum density per table 17.05.140 of this section is 100 dwelling units, applicant may build 105 units if 10 percent of the property is dedicated; applicant may build 110 dwelling units if 20 percent of the property is dedicated, etc.), if a project retains open space in the manner and for the purposes described in subsection B5 of this section.
5. Open Space Standards: In order to utilize clustering, have minimum lot sizes waived, and/or obtain density bonuses, open space for the following purposes shall be maintained:
a. Natural drainageways;
b. Recreational trails;
c. Public access to publicly owned lands;
d. Preservation of ridge tops and scenic features when identified on the natural features overlay map of the comprehensive plan;
e. Preservation of existing vegetation;
f. Preservation of sensitive wildlife habitat.
The open space must be dedicated to and accepted by a public agency, or in certain circumstances, if the land can be maintained and managed in perpetuity, a homeowners' association.
C. Grading Standards:
1. All excavation and grading shall be by separate permit and shall conform to the requirements of all building codes as adopted by the city and as further regulated by this chapter. If a conflict occurs between this chapter and any building codes as adopted, the more restrictive standard shall apply.
2. Grading shall be minimized; but where alterations to topography are necessary, slopes shall be contoured to provide a smooth, gradual transition and imitate the natural character and appearance of the existing terrain.
3. All development shall meet city requirements for drainage and erosion control.
4. Unless approved as part of an overall development plan subject to the provisions of this chapter, no disturbance of existing slopes of thirty five percent (35%) or greater shall be allowed except as provided for below:
a. Conformance with requirements of all building codes as adopted by the city;
b. The area of thirty five percent (35%) or greater slope to be disturbed is less than ten percent (10%) of the total parcel or a maximum of two (2) acres, whichever is greater, unless the disturbance is for construction of recreational trails or necessary utility or road connections;
c. The purposes for which the area is to be disturbed cannot be reasonably accommodated elsewhere on the parcel such as utility construction, access roads, or street connections to abutting properties;
d. The area of thirty five percent (35%) or greater slope to be disturbed contains no existing natural or manmade drainageways unless the disturbance is for construction of recreational trails or necessary road or utility constructions where drainageways are maintained or reestablished; and
e. All disturbed areas are immediately stabilized and revegetated in accordance with an approved revegetation plan. (Ord. 3075, 2021: Ord. 2896, 2011: Ord. 2846 § 1, 2008)