Storm water runoff control addresses both peak rate and total volume of runoff.
(a) The storm drainage system installed shall carry a minimum five year 24 hour frequency storm. The design of which shall conform to the Urban Hydrology for Small Watersheds, Technical Release Number 55, by the Soil Conservation Service of the United States Department of Agriculture and its Ohio Supplement or The Rational Method. The retention/detention area shall have a storage capacity determined with a minimum for a ten year 24 hour frequency storm by the Critical Storm Method of the Critical Storm Calculation Quick Detention Sheet, which is available in the office of the Village Administrator.
(b) The peak rate of discharge from the retention/detention area shall not exceed a two year 24 hour frequency storm based on pre-development conditions.
(c) Storage volume does not have to be provided for off-site upstream areas. Flow from such areas will be routed through the drainage system in the development under consideration at a rate determined in the same manner as the on-site system. Off-site land uses over the last year before the development shall be considered as the pre-development condition for the purpose of calculating changes in runoff.
(Ord. 864. Passed 5-4-09.)