Sec. 21-44. - Special definitions.

Average slope of a parcel of land or any portion thereof shall be computed by applying the formula S = (.00229 IL)/A to the natural slope of the land, before grading is commenced, as determined from a topographic map conforming to National Mapping Standards and having a scale of not less than one inch equals two hundred feet and a contour interval of not less than five feet. The letters in this formula shall have the following significance:

S = The average cross slope of the land in percent.

I = The contour interval.

L = The combined length of all contours in feet, excluding the length of contours in drainage channels below the twenty-five year flood level.

A = The net area of parcel or portion thereof, in acres, after deducting all areas in drainage channels below the twenty-five year flood level, for which the slope is to be determined.

Unstable geological or soil formations includes but is not limited to formations having stability problems, susceptibility to slippage or subsidence, vulnerability to erosion and other special geological and soil conditions potentially hazardous to persons or property, or both.

Special treatment area means and includes land having physical characteristics which require application of one or more special conditions in order to protect and preserve the public health, safety and welfare. It shall include many areas of land containing extensive hillsides or rugged terrain. The Board of Supervisors, upon recommendation of the Planning Commission, may by resolution or minute order designate by map or metes and bounds description, or otherwise, areas in the County which shall be deemed to be "Special Treatment Areas" by reason of conditions affecting such areas generally.

(Ord. No. 1751, § 2)