Vehicular ways shall be graded and drained in such a manner that will not allow erosion or endanger the stability of any adjacent slope. Surface discharge onto adjoining property shall be controlled in such a manner that it does not cause erosion or endanger existing improvements, and shall conform to the provisions of SCC 12.08.560. Bridges and culverts installed over or in watercourses must be approved by the Planning Director and any other required permitting agency (including but not limited to: California Department of Fish and Game, regional water quality control board, U.S. Army Corps of Engineers, etc.).