All storm water storage facilities shall be designed with sufficient capacity to accommodate all runoff caused by the development in excess of the runoff which would have resulted from the site if left in its natural, undeveloped condition. The storage capacity of all storage facilities shall be sufficient to store 115% of the excess flow, in each water shed, which would result from the 100-year storm of 24-hour duration.
('69 Code, § 5-18(b)(3)) (Ord. O-83-1, passed 5-9-83)