Cooper River (South Carolina)

Cooper River
The Arthur Ravenel Jr. Bridge over the Cooper River in Charleston, South Carolina

The Cooper River is a mainly tidal river in the U.S. state of South Carolina. The South Carolina cities of Mt. Pleasant, Charleston, North Charleston, Goose Creek, Moncks Corner, and Hanahan are located along the river. Short and wide, it is joined first by the blackwater East Branch, then farther downstream, the tidal Wando River. Almost immediately thereafter, the river widens into its estuary, uniting with the Ashley River to form the Charleston Harbor.

Long used as an important commercial waterway, the West Branch of the Cooper River was initially connected to the Santee River near its navigation head by a canal built in the late 18th century. Though the West Branch still rises as a blackwater swamp in central Berkeley County, its main headwaters have been seamlessly shifted to Lake Moultrie by the 1940s vintage Tail Race Canal. Lake Moultrie is, in turn, fed from Lake Marion by a diversion canal built around the same time period. This artificial rerouting of the Cooper River basin has essentially unified the Santee and Cooper River systems into a single hydrological drainage entity.

The river was named for Anthony Ashley Cooper, 1st Earl of Shaftesbury and chief Lord Proprietor of the Carolina Colony. Charleston was founded on the western bank of the Ashley River in 1670 (at Charles Towne Landing), before moving across to its current peninsular location ten years later.