(a) Storm drainage facilities for a subdivision or development shall be designed to accommodate runoff from the ten year storm frequency. Site design and grading plans shall provide emergency drainageways in order to avoid both damage to structures and endangering public safety, which emergency drainageways shall be designed to accommodate runoff from storms exceeding the ten year storm frequency, but not exceeding 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 flow 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) These requirements must be met at each point storm water is discharged from a development area.
(e) In some cases the City Engineer may require the submittal of additional information on the existing and proposed drainage system and on the effects on existing drainage or natural waterways.
(Ord. 05-79. Passed 6-7-05.)