18.34.030 Average Percent of Slope.
A. The average percent of slope is calculated using the following formula:
S = (100 × I × L) ÷ A
where “S” is the average percent of slope; “I” is the contour interval in feet; “L” is the summation of length of the contour lines in feet less the length of the average contour line; i.e., L = total length of contour lines – total length of contour lines divided by total number of contour lines; and “A” is the area of the lot being considered in square feet.
B. Slope calculations shall be based on accurate topographic survey maps of the following minimum standards:
1. For parcels under one acre in size, the map scale shall not be less than one inch equals eight (8) feet (one-eighth scale).
2. For parcels of one acre up to ten (10) acres, the map scale shall not be less than one inch equals thirty (30) feet.
3. For parcels ten (10) acres or larger in size, not less than one inch equals forty (40) feet.
4. Maps of any scale shall use a five-foot contour interval or less.
C. For the purpose of determining required natural state, density adjustments, and FAR ratios, the calculated slope shall be rounded off to the nearest one percent.
D. The calculation of slope shall exclude vehicular easements, which are not applicable to required natural state, density adjustment, and FAR ratios. (Ord. 1030 § 2(12), 2018; Ord. 934 § 2, 2004; Ord. 929 §§ 25, 26, 27, 2004; Ord. 689 § 2, 1983; Ord. 471 § 1 (part), 1973)