Deviations from the provisions of this section and Section 7012(a) of the Uniform Building Code shall be specifically addressed for each instance in the reports required by Section 7006 of the Uniform Building Code.
Terrace. Terraces at least eight feet in width shall be established at not more than twenty-five foot vertical intervals on all cut or fill slopes to control surface drainage and debris except that where only one terrace is required, it shall be at midheight. For cut or fill slopes greater than fifty feet and up to one hundred feet in vertical feet in width. Terrace widths and spacing for cut and fill slopes greater than one hundred feet in height shall be designed by the civil engineer and approved by the city engineer and shall meet or exceed the foregoing requirements. Suitable access shall be provided to permit proper cleaning and maintenance.
Swales or ditches on terraces shall have a minimum gradient of five percent and must be paved with reinforced concrete not less than three inches in thickness. They shall have a minimum paved width equal to the width of the terrace.
A single run of swale or ditch shall not collect runoff from a tributary area exceeding thirteen thousand five hundred square feet (projected) without discharging into a down drain.
A design height of the slope shall include six feet at the top of the slope to provide for the contributory area and height of possible walls along the top of the slope.
Exception: the width and spacing of the terraces may be approved by the city engineer to be narrower and spaced differently than the preceding requirements provided:
A. The terrace system is designed by a civil engineer and approved by the soils engineer. Such design shall include sufficient details and calculations (including hydrology) to enable full analysis by the city engineer.
B. The maximum vertical interval shall be twenty feet, an eight-foot wide terrace shall be included at fifty feet in vertical height, and a twelve-foot wide terrace shall be included at eighty feet in vertical height.
C. Building roads shall have a drainage gradient of at least one-half percent toward approved drainage facilities.
D. The exception in Section 7012(d) of the Uniform Building Code is deleted.
(Ord. 294, 1982; Ord. 514 § 2, 1987)