(A) Storm drainage facilities for the subdivision or development shall be designed to accommodate runoff from the 100-year storm. Site design and grading plans shall provide emergency drainageways to avoid damage to a structure and to avoid endangering public safety, which emergency drainageways shall be designed to accommodate runoff from the 100-year storm frequency.
(B) If the collector facilities cannot be located in street rights-of-way, then they shall be located adjacent to side or rear lot lines where easements shall be provided to and along the facilities.
(C) All storm water flow from the proposed subdivision or development, including flows from upstream areas passing through, and further including increased flow attributable to changes in time of concentration or changes in the former runoff factor (imperviousness), shall be conveyed to the proper outlet for the entire tributary area via a natural channel or pipe/culvert either or both of which shall be improved so as to be of adequate capacity.
(D) “Emergency flow way” means the flow routes and drainageway necessary to convey the 100-year storm through a development.
(E) These requirements must be met at each point storm water is discharged from a development area.
(F) In the event that retention or detention structures exceed specified sizes, required inspection and permits from the Ohio Department of Natural Resources Division of Water are required.
(G) In some cases, the City Engineer may require the submittal of additional information (HEC-1 or HEC-2) on the existing and proposed drainage system and the effects on existing drainage or natural waterways.
(Ord. 1-91, passed 1-7-1991; Ord. 15-16, passed 2-22-2016; Ord. 07-2021, passed 2-1-2021)