A. To reasonably mitigate the transportation of sediments to storm drains, drainage or waterways, Erosion and Sediment Control Plans (ESCPs) are required as specified in Larkspur Municipal Code Section 9.11.100. The Director of Public Works may also require a soils engineer’s report covering the erosion characteristics of the site’s soils. The soils engineer’s report shall be submitted together with the ESCP. All controls and facilities shall be designed in accordance with the soils report and consistent with the ESCP requirements specified in Larkspur Municipal Code Section 9.11.100. The City may also require more stringent controls.

B. Drainage facilities shall be designed so as to provide capacity necessary to carry off a twenty-five-year storm, unless otherwise required by the officer granting the permit, but in no case shall culverts in the public rights-of-way be less than fifteen (15) inches in diameter.

C. Subsurface Drainage. Where evidence indicates the presence of subsurface waters which may contribute to sliding or settlement of the earth surface either in an undisturbed state, or likely to result from grading operations, the City may require the construction of, or installation of, such subsurface and surface facilities as may be deemed necessary to collect such subsurface waters as may contribute to the existing or anticipated slide or settlement condition and may require its conveyance to an adequate natural watercourse or public drainage system.

D. Ground Cover. Whenever slope surfaces result from grading operations on the site, suitable vegetation for ground cover as specified in California Stormwater Quality Association Stormwater Best Management Practices Construction Handbook or equivalent shall be planted and maintained until growth is established. (Ord. 1005 § 4, 2015; Ord. 696 § 1 (part), 1983; Ord. 662 § 2, 1981; Ord. 288 § 6D, 1962)