The South Carolina portion of the lower Savannah River Basin (hydrologic units 03060106, 03060107, 03060109, 03060110) is located in Edgefield, Aiken, Barnwell, Allendale, Greenwood, McCormick, Saluda, Hampton, Jasper, and Beaufort Counties and encompasses 16 watersheds and 2,524 square miles. The basin extends from the Piedmont to the Sandhills to the Upper and Lower Coastal Plains and on into the Coastal Zone regions of the state. The lower Savannah River Basin extends into Georgia. There are 2,306,099 acres in the extended watershed; 692,120 acres or 30.0% are outside of South Carolina. The South Carolina portion of the lower Savannah River watershed consists of 56.4% forested land, 16.4% forested wetland (swamp), 14.0% agricultural land, 6.3% urban land, 3.9% nonforested wetland (marsh), 2.3% water, and 0.7% barren land. The urban land percentage is comprised chiefly of North Augusta, Aiken, Bluffton, and a portion of Hilton Head Island. Federal lands, such as the Savannah River Site and the Savannah National Wildlife Refuge, are sizable portions of this basin. There are approximately 6,010 stream miles, 19,349 acres of lake waters, and 24,788 acres of estuarine areas in this extended basin.
The Savannah River flows out of the Thurmond Dam and is restricted again by the Stevens Creek dam, forming Stevens Creek Reservoir. Stevens Creek accepts drainage from Turkey Creek (Beaverdam Creek) and enters the Savannah River prior to the dam. Downstream of the Stevens Creek dam, the Savannah River accepts drainage from Horse Creek, Hollow Creek, Upper Three Runs, and Lower Three Runs (Par Pond). At the base of the Savannah River Basin, the Calibogue Sound accepts drainage from the May River, the Cooper River, and Broad Creek before joining with the Savannah River as it flows into the Atlantic Ocean near Savannah, Georgia. The Atlantic Intracoastal Waterway (AIWW) connects Calibogue Sound to Port Royal Sound and to the Savannah River crossing the New River (Great Swamp) and the Wright River.
For an overview of water quality in the Lower Savannah River Watershed, download the water quality assessment summary. For specific basin descriptions, facts, figures, and detailed maps click on a watershed below.