(A) Retaining walls shall be used in areas where the vertical height of cuts or fills exceeds ten-feet from the finished grade of the adjacent road. A Building Department permit is required for any retaining wall over 48 inches in height as per the adopted International Building Code (IBC).
(1) For purposes of this standard, the height of the cut shall be measured to the point where the cut achieves a stable embankment and the height of the fill shall be measured to the point where the fill ends using a two foot horizontal to one foot vertical fill design.
(2) Retaining walls shall be terraced to achieve an eight-foot maximum height. Where feasible, a road segment otherwise requiring a long retaining wall shall be designed to provide for the use of shorter wall segments (generally not exceeding 200 feet).
(3) When a retaining wall is used, the vertical height of the cut shall not exceed ten feet measured from the top of the wall to the point where the cut transitions to natural grade and the vertical height of a fill shall be measured from the top of the retaining wall to the finished grade of the adjacent road. Retaining walls shall be tiered if necessary to achieve the maximum vertical cut or fill of ten feet.
(B) Building construction on slopes exceeding 25% warrant especial close review for all grading, retaining wall, cut/fill and roadway grade standards. No building shall be allowed on grades exceeding 30%.
(Ord. 2017-02, passed 11-13-2017)