Urban development has had little impact on the region. With a population of 12,600, the Pamlico Sound drainage basin has the lowest population density in the study area. Military land covers about 200 acres and 21 marinas are located in the waters of the Pamlico Sound drainage basin. Thirty-three percent of the freshwater streams and rivers within the basin are impaired. For this reason, the entire river basin is considered nutrient sensitive due to elevated nitrogen and phosphorus levels.
Sedimentation is the primary cause of water quality degradation in freshwater segments of the basin.
Elevated nitrogen and phosphorus concentrations, primarily from agricultural practices in the basin, are responsible for accelerated eutrophication in the lower Tar-Pamlico River. The highest nitrogen concentrations are found in the upper riverine stations at Tarboro, Grimesland, and Washington. Short retention times in the swiftly moving upper Tar River, however, prevent excessive phytoplankton growth. As the river mixes with the salty water of Pamlico Sound, settling, assimilation, and dilution with nitrogen-poor seawater cause reduced nitrogen levels in the Pamlico River tributaries of Van Swamp, Pungo River, and Durham, Pungo, and Pantego Creeks. Total phosphorus values are generally highest in the mainstream Pamlico River from Tarboro to the Pamlico Sound.