Measurement and Modeling of Hydrologic Response in a Southern New Jersey Watershed

Southern New Jersey is part of the Atlantic Coastal Plain, with generally flat topography and sandy soils. Hydrologic estimation techniques employed by state regulatory agencies typically rely on NRCS methods such as TR-55 and TR-20 with pre-defined runoff hydrographs. While these techniques work reasonably well in the steeper Piedmont regions of northern New Jersey, they typically over-predict runoff quantities in southern New Jersey by an order of magnitude. Several alternative unit hydrographs have been proposed for coastal plain regions, including the DelMarVa unit hydrograph, developed for the Delaware-Maryland-Virginia peninsula, and the Upper Maurice River unit hydrograph in southern New Jersey. To verify the applicability of these types of alternative approaches, a study has been conducted in support of developing Regional Stormwater Management Plans for several watersheds in the region.