Final Report: Quantifying NPS Pollutant Discharges from an Urbanizing Headwater Basin

This research evaluates nonpoint source (NPS) sediment and nutrient fluxes from four headwater basins in the Piedmont physiographic province of the Chesapeake Bay drainage for up to 24 years. The basins are part of the 1530 km2 Occoquan River watershed in northern Virginia. Three of the basins, ranging in size from 67 to 400 km2, are predominantly forest and/or mixed agriculture. The fourth basin, the 127 km2 Cub Run watershed, is rapidly urbanizing with approximately 50 percent of current land area classed as urban. Descriptions of the four Occoquan headwater basins, averaged over the study period, are presented below for reference throughout the document.