Del. Code tit. 7, § 4003A

All land development subject to this chapter in the Mill Creek, Little Mill Creek, Red Clay Creek, White Clay Creek, Persimmon Creek and Shellpot Creek watersheds of New Castle County will, in addition to meeting all other requirements for stormwater management, be required to demonstrate successful management of any increase in stormwater runoff volume from predevelopment land use conditions. Successful management of increased stormwater volume shall include but not be limited to; recharge, infiltration and reuse where soils and site conditions are applicable. For any increase in volume that cannot be recharged, infiltrated or reused, volume management may be achieved by modifying the release rate for the increase in volume so as not to increase the flood elevation for all storms up to and including the 100-year return period.