Wet detention basins shall be designed to remove stormwater pollutant, to be safe, to be aesthetically pleasing, and as much as feasible to be available for recreational use.
(A) All wet basins shall be designed to provide fish habitat.
(B) “Management of small lakes and ponds in Illinois” (IDNR, revised 1997) provides guidance for design of fishing ponds in Illinois. The applicant is encouraged to contact the local IDNR Fisheries Biologist for additional information.
(C) Wet basins shall have a minimum depth of at least five feet with a minimum depth of ten feet over 25% of the bottom area of the basin to prevent winter freeze out.
(D) The minimum normal water elevation surface for a wet basin shall be one acre.
(E) The side slopes of wet basins at the normal pool elevation shall not be steeper than 5:1.
(F) A ten-foot wide safety ledge shall be provided below the normal water level with a maximum depth of three feet and a maximum side slope of 10:1.
(G) The permanent pool volume in a wet basin at the normal water elevation shall be equal or greater to the runoff volume from its watershed for the two-year frequency event.
(H) To the extent feasible, the distance between detention inlets and outlets shall be maximized. If possible, inlets and outlets should be located at opposite ends of the basin.
(Ord. 07-02, passed 4-16-2007)