All cut or fill slopes exceeding forty feet in vertical height shall have drainage terraces at vertical intervals not exceeding thirty feet except that where only one terrace is required, it shall be at approximately mid-height unless some other location is approved by the County Official. Such drainage terraces shall be at least six feet wide and be designed and constructed so as to provide a swale or ditch having a minimum depth of one foot and a minimum grade of two percent unless a flatter grade is approved by the County Official. The terrace including the swale or ditch shall provide a paved drainage way based upon the need as determined by the slope, wetted perimeter and discharge that drains into a paved gutter, pipe or other safe disposal area. Such drainage terraces including the swales and ditches shall be paved with a minimum thickness of three inches of portland cement concrete, or with two inches of pneumatically applied concrete mortar, or shall be improved with other materials or with other treatment approved by the County Official as equal. If the drainage discharges onto natural ground, the County Official may require that such natural ground be protected from erosion outlet protection/velocity dissipation devices. Drainage terraces or the paving thereof may be waived by the County Official after receipt of the report by the soil engineer certifying that he or she has investigated the property and that in the engineer's opinion drainage terraces or paving is unnecessary.
(Added by Ord. No. 9547 (N.S.), effective 5-9-03)