(A) Any subdivision shall make adequate provision to control the rate of storm or flood water runoff by stormwater management measures, such as a constructing a stormwater detention pond. Stormwater management measures must be designed to accommodate runoff from any upstream area potentially draining into or through the area to be subdivided. Such design shall assume that the upstream area will be regulated such that the stormwater discharge shall be equal to the runoff from the existing condition for the design storm events.
(B) Stormwater conveyance and detention shall be designed according to the Statewide Urban Design and Specifications (SUDAS) design manual and standard specifications manual or its successor, and the city Supplemental Specifications to the SUDAS manuals. In particular, the stormwater release rate from the developed site during a 100-year storm event shall not exceed the stormwater runoff rate from the existing, pre-developed site during a five-year storm event.
(C) Any necessary and appropriate public stormwater management measure shall be located in either the public right-of-way or in a drainage easement secured by the developer and dedicated to the city. Any stormwater detention facility shall be located in a drainage easement.
(D) The developer is responsible for soil erosion and sedimentation control. The developer shall provide the city with a copy of the National Pollutant Discharge Elimination System (NPDES) discharge permit authorization from the Iowa Department of Natural Resources for coverage of the subdivision.
(Ord. 2217, passed 11-4-2013)