The hydrologic criteria to be used for the C-SWPPP’s Stormwater Management and Sediment Control section shall be as follows:
(a) Twenty-five-year 24-hour duration design storm for all cross-drain culverts and drainage designs.
(b) Ten-year design storm for all interior culverts and drainage conveyance system designs, plus 25-year design storm for all channels conveyances.
(c) Two-year, 10-year and 25-year design storms for all detention and retention basins using procedures contained in the Stormwater Management Design Manual or approved by the Director.
(d) All drainage designs shall be checked using the 100-year storm for analysis of local flooding, and possible flood hazards to adjacent structures and/or property.
(e) All hydrologic analysis will be based on land use conditions.
(f) For the design of storage facilities, a secondary outlet device or emergency spillway shall be provided to discharge the excess runoff in such a way that no danger of loss of life or facility failure is created. The size of the outlet device or emergency spillway shall be designed to pass the 100-year storm as a minimum requirement.
(1976 Code, § 8-83) (Ord. 3551, passed 11-11-2001; Ord. 4281, passed 5-5-2009; Ord. 4698, passed 5-5-2015)