In some areas, land development has increased at rates that exceed the limitations of common land management practices, and is difficult to track within the lower Savannah-Salkehatchie watershed. Maintaining high water quality will continue to be a controversial issue from both environmental and economic perspectives in the years to come. In South Carolina, the coastal population is expected to increase by 50 percent in the next 20 years. Without the appropriate urban water quality BMP implementation, substantial increases in sediment and nutrients can cause detrimental eutrophic conditions in estuarine systems. During the past twenty years, most of state and federal resources have been directed at reducing point source discharges to surface waters.
Point sources are relatively easy to control and regulate because of their known location.
Sediment runoff is one of the leading contributors to NPS pollution. These sediments carry pesticide residues and excessive nutrients such as nitrogen and phosphorous from fertilizers. Other sources of sediments that contribute to water quality degradation include accelerated soil erosion caused by urban runoff, excess nutrients and pathogens washed from feedlots and leaking sewage systems, and unfiltered stormwater discharge. Sediments in storm runoff carry excess nutrients into nearby waterbodies which stimulates algal growth, limit plant photosynthesis, and accelerate surface water eutrophication, leading to increased macrophyte growth and fish kills. Despite the recent advances in legislative measures and BMP techniques for water quality control, significant nutrients, pesticides, and trace elements still exist in the environment.