What requirements for storm water quantity management must be addressed through the SWMP?
There are two scenarios for storm water quantity management in the SWMP: (1) Development or redevelopment that increases the amount of impervious area by 0.5 acre or more must adhere to the requirements in Chapter 13 of the Milwaukee Metropolitan Sewerage District (MMSD) Rules. Normally this limits the discharge from the development to 0.15 cubic feet per second (cfs) per acre for the 2-year storm event and 0.5 cfs per acre for the 100-year storm event. (2) Development or redevelopment that requires an SWMP and does not increase impervious area by more than 0.5 acre must limit the post-development peak runoff rates to at least 10% less than pre-development peak runoff rates for the 2-year and 100-year storm events.
