Hillsides are geologic features of the natural landscape located between the base or foot of a hill or mountain and its summit. River terraces and coastal bluffs which have a geologic investigation and report within areas of demonstration are not included within the definition of hillside lands (they are subject to their own standard of review). The following criteria apply to hillside lands which in general have a slope grade of ten percent or greater and a minimum height difference of fifty feet or greater in elevation between the base and the summit:
A. No development shall occur on land over thirty percent prior to grading. For the purposes of this section, development includes the building site, sewage disposal areas, accessory buildings, and the driveways to the building site and access roads to the site(s). Exceptions for driveways and access roads, refer to subsection B of this section.
B. Driveways and access roads, approved as part of the engineered road improvement plan, may be permitted across slopes of thirty percent or greater where it is demonstrated by the engineer that such crossings have been limited to the maximum extent possible and that relocation or realignment is not practical. These driveways and access roads shall not exceed a ratio of four hundred feet of length for each twenty thousand square feet of developable land served by the subject access road or driveway.
C. Areas proposed for hillside development, as defined above, shall be assessed by an engineer or geologist as to slope stability, soils risks, erosion hazard, and other slope risk factors.
D. No development, as defined in subsection A of this section, shall occur in areas with a slope of twenty to thirty percent which are assessed by an engineer or geologist as having high to very high soils risks.
E. Any lot approved shall have a delineated contiguous area of twenty thousand square feet of developable land or two immediately adjacent areas that total twenty thousand square feet of developable land of which one must be at least fifteen thousand square feet in area. The purpose of this area is to locate the residence, sewage disposal areas, and any accessory buildings.
F. The aggregate density for any hillside project shall not exceed one residential unit per two acres for the gross acreage of the project.
G. All hillside parcels shall provide for a minimum setback of thirty feet for buildings and accessory buildings from all property lines.
(Ord. 91-26 § 8 (part), 1991.)