(A) It is recognized that the smaller streams and drainage channels serving the city may not have sufficient capacity to receive and convey stormwater runoff resulting from continued urbanization. Accordingly, the storage and controlled release rate of excess stormwater runoff shall be required for any development, redevelopment and new construction located within the city which requires development plan approval under Chapter 158 of the City of Huntington Code of Ordinances, or which requires subdivision plat approval under Chapter 156 of the City of Huntington Code of Ordinances.
(B) The developer must submit to the city detailed computations of runoff before and after development, redevelopment or new construction which demonstrate that release rate of runoff will not be increased.
(C) These computations must show that the peak runoff rate after development for the 100-year return period storm of critical duration must not exceed the two-year return period pre-development peak runoff rate. The “CRITICAL DURATION STORM” is that storm duration that requires the greatest detention storage.
(D) Computations for areas up to and including 200 acres may be based on the Rational Method; typical runoff coefficients are listed herein. For areas larger that 200 acres, hydrography techniques and/or computer drainage modeling methods may be used. Hydrograph techniques and computer modeling methods used to determine stormwater runoff shall be proven methods, subject to approval of the Commission.
(Ord. 16-C-98, passed 6-9-98; Am. Ord. 22-C-98, passed 8-11-98; Am. Ord. 22-C-04, passed 11-9-04)