Santee River Basin Study
Project Maps and Spatial Data

Study unit map - The Santee River Basin and coastal drainages includes about 24,000 square miles in North and South Carolina. The Santee River has the second largest drainage area in the Eastern United States, and its basin makes up 70 percent of the study area. The basins of the Cooper, Edisto, and numerous smaller rivers make up the remainder of the study area.

Landuse - Land use in the Santee Basin includes about 60 percent forested, 30 percent agricultural, and 6 percent urban lands.

Water Quality Sampling Sites - The Santee River Basin and coastal drainages (the “Santee Basin”) is an approximately 24,000-square-mile area in North and South Carolina that encompasses the Blue Ridge Mountains, the Piedmont, and the Coastal Plain (Fenneman, 1946). Most of the 3.5 million people in the Santee Basin live in urban areas. Eighty-six percent of the water used in homes and for industry is treated surface water withdrawn from rivers or reservoirs. Ground water is the main water source for rural households.

Average Annual Precipitation - Precipitation affects water quality by producing runoff to streams and infiltration to aquifers.

Radon Concentrations - Radon concentrations were highest in the Piedmont and Sandhills aquifers, resulting from naturally high levels of uranium in near-surface rocks and sediment.

Stream Chemistry and Biology Sampling Sites - Fixed sites were sampled to examine differences in streamwater quality due to the environmental setting, a combination of land use, geology, physiography, and climate.

Ground Water Chemistry Sampling Sites - Subunit surveys were conducted in three drinking-water supply aquifers to assess overall water quality. Land-use studies in urban and agricultural settings evaluated the effects of these land uses on shallow ground water. An agricultural flow-path study examined the transport and fate of nutrients and pesticides in shallow ground water.

Special Studies Sampling Sites - The effects of a forested wetland on nutrient concentrations in stream water were studied as part of the Forested Wetland Initiative, a joint research project with the U.S. Forest Service.