Dry-bottom stormwater storage basins shall only be permitted if approved by the Board of Public Works as a waiver, under the conditions of this subchapter. Stormwater storage facilities, which are designed to have dry bottoms, must be designed to include under drains, to drain the bottom of the stormwater storage facility, so that the facility can be maintained. In addition, the bottom of the facility shall be designed to have a longitudinal slope of 1.3% and traverse grade to the outlet, so that the facility will empty, leaving no ponded water. Detention basins with less than 1% must be provided with subsurface drainage or paved gutters. Recreation facilities, aesthetic qualities, open space or secondary use shall be considered in planning in detention facilities. Max planed depth of storm water stored with out a permanent pool shall not exceed four feet.
(Ord. 2-2010, passed 3-8-10)