A river rising in the Blue Ridge of western North Carolina and flowing about 402 km (250 mi) generally southward into South Carolina, where it is called the Wateree River. River, southeastern U.S. Rising in North Carolina's Blue Ridge, it flows south into South Carolina, where it becomes the Wateree River. It is 220 mi (350 km) long. With the Wateree, it forms an important source of hydroelectric power for South Carolina