Report Follows

Nonpoint Source Pollution (NPS) is an important source of water quality impairment in streams, estuaries, and near coastal ocean waters throughout the United States, including the Virgin Islands (DPNR 2003A). In order to quantify loading of nonpoint source pollutants from river and stream systems, it is generally necessary to have information on both the concentration of the pollutants and the water flow that transports the pollutant into the receiving waters. Hydrologic modeling is often used to estimate river discharge and stormwater flow based on rainfall, land use, elevation, soils, and other meteorological data. Concurrent with water quality studies, these models may present a powerful tool for estimating pollutant loads. The recent Dissolved Oxygen TMDL for Mangrove Lagoon and Brenner Bay, St. Thomas, U.S. Virgin Islands (DPNR 2003B) notes that reductions in Biological Oxygen Demand (BOD) loading from nonpoint sources within Turpentine Run Gut system will be necessary to achieve the proposed TMDL BOD limits. The development of a detailed hydrologic model would allow coastal mangers to better estimate the loading of BOD and various additional pollutants from Turpentine Run into the Mangrove Lagoon, whic