South Carolina has an abundance of rivers that originate from within the state or that enter from North Carolina and Georgia and drain land as far away as Virginia. These rivers flow generally from the northwest to the southeast, following the geography from high elevations in the Blue Ridge and Piedmont to the lower elevations of the coastal plain.
South Carolina has an abundance of rivers that originate from within the state or that enter from North Carolina and Georgia and drain land as far away as Virginia. These rivers flow generally from the northwest to the southeast, following the geography from high elevations in the Blue Ridge and Piedmont to the lower elevations of the coastal plain. The Blue Ridge and Piedmont contain narrow drainage divides between river tributaries, some only a few miles wide. The result is a landscape that is almost completely dissected by streams and rivers. Some rivers begin at the base of the Sandhills and cross over the coastal plain to the Atlantic Ocean. Others begin outside of the state and flow into South Carolina, forming three large river systems: the Santee, the Savannah, and the Pee Dee.
The Santee River system is the largest on the east coast. It drains water from North Carolina and carries it through South Carolina through three major rivers (Saluda, Catawba, Broad) and through smaller tributaries (Enoree, Tyger, Reedy). The Broad and the Saluda join at Columbia to form the Congaree River. Geomorphic features of interest on the Congaree floodplain include oxbow lakes and an extensive series of meanders. In the north, the Catawba River enters South Carolina near Rock Hill and is renamed the Wateree as it flows south to form Lake Wateree. Further downstream just above Lake Marion, the Wateree and the Congaree join to form the Santee River, which then flows into the Atlantic Ocean, forming the Santee Delta just south of Georgetown.
During the 1930s and 1940s the Santee River system was dammed in several places to form lakes for flood control, hydroelectric power, and recreation. A major geological and ecological change resulted. The sediment load previously carried by the river water was diverted as the water passed into the lakes. As the river water slowed, the sediments fell and collected on lake bottoms and behind dams, instead of flowing down the river to the coast. After 1942, when the dams and lakes opened, there was a marked decrease in water and sediment flow down the Santee River. This decrease in turn prevented the long-shore ocean currents from moving the sand up and down the coast to nourish the barrier islands, which has resulted in their erosion. Silting of Charleston harbor also became a problem. Since 1985 a rediversion canal has diverted some of the water and sediment back into the Santee River. This has lessened the sedimentation of the harbor.
The Savannah River system forms the western boundary of South Carolina and drains water from portions of North Carolina and Georgia as well as South Carolina. Rivers that help to form it are the Chattooga, Tugaloo, and Keowee. The Savannah River empties into the Atlantic Ocean at Savannah, Georgia. Like the Santee, the Savannah River system has been dammed in several places, forming massive man-made lakes. The Savannah is the only river system in South Carolina in which large ships can travel upstream for any distance.
The third river system in South Carolina is the Pee Dee, which is the only system in the state left undammed. Rivers that form the Pee Dee system include the Great Pee Dee, Little Pee Dee, Waccamaw, Black, and Lynches. Two smaller rivers, the Sampit and Pocotaligo, are also part of the Pee Dee system, which enters the Atlantic Ocean at Winyah Bay in Georgetown.
Some of the most beautiful rivers in the state are those that begin on the coastal plain. Because they move slowly over the low relief of the coastal plain to the Atlantic, they do not transport large amounts of sediment. As a result, they are clearer than the rivers that cross the Piedmont. Tannic acid in the organic matter found in these rivers gives them a dark cast, and so they are known as “black rivers.” The North and South Forks of the Edisto River begin in the Sandhills in Lexington and Aiken Counties and end at the Atlantic at Edisto Island. The Edisto is the largest of the black rivers in South Carolina and one of the most pristine. Several state parks have been built along its banks to accommodate recreational uses. Other black rivers include the Waccamaw, Black, Pocotaligo, Salkahatchie, Combahee, Coosawhatchie, Ashley, Cooper, and Ashepoo.
Other rivers of importance in South Carolina include those relatively small mountain streams that provide the scenic beauty of rapids and waterfalls. South Carolina has a favorable climate with sufficient rainfall and a high relief, which has endowed it with natural waterfalls in the upstate. There are more than fifty waterfalls in the state, primarily in the Blue Ridge and upper Piedmont in Oconee, Greenville, and Pickens Counties. The spectacular Whitewater Falls in Oconee County has the highest series of falls in eastern North America. Many of the falls have been protected through the establishment of state and county parks.
Kovacik, Charles F., and John J. Winberry. South Carolina: The Making of a Landscape. 1987. Reprint, Columbia: University of South Carolina Press, 1989.
Murphy, Carolyn H. Carolina Rocks! The Geology of South Carolina. Orangeburg, S.C.: Sandlapper, 1995.