Cooper River (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 the Santee 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, before moving across to its current peninsular location ten years later.
Rice and indigo were heavily cultivated on plantations surrounding the brackish marshland of the Cooper River from the early Colonial through the end of the Civil War periods. Former plantations along the river include Lewisfield, Mulberry, Middleburg, Quinby and Mepkin, which is now Mepkin Abbey, a Trappist monastery. Many of these and other structures form the Cooper River Historic District, a national historic district located along both branches of the river. In addition to the Mepkin Abbey Botanical Garden, nearby attractions include the Cypress Gardens and the Old Santee Canal Park.
Daniel Island and Drum Island are adjacent to the river. Cargo terminals, a paper mill, and the former Charleston Naval Base line its shore. The Patriot's Point naval & maritime museum sits at the mouth of the river. Berthed at Patriot's Point are four museum ships, most notably, a World War II aircraft carrier.
Goose Creek, a tributary of the Cooper River was the site of a U.S. Navy submarine base through the late 1990s and functioned as a nuclear weapons handling facility servicing fleet ballistic submarines until the advent of the larger Trident submarine-launched ballistic missile which drove the s to require a deeper draft.

Crossings

Motorists have been able to cross the Cooper River under their own power for approximately eight decades, when it was first spanned by the John P. Grace Memorial Bridge. As the Grace Bridge quickly became both functionally and structurally deficient, the State of South Carolina built a parallel span, the Silas N. Pearman Bridge, a few yards to the south in 1966. These highly overstressed spans were, for over a quarter of a century, the only connection between Charleston and the rapidly growing suburb of Mt. Pleasant until the Don Holt Bridge, built a few miles upriver as part of the I-526 corridor, became the third bridge to span the river in 1992.
In service since August 8, 1929, the Grace Memorial Bridge was the oldest of the three. Named for the commissioner who inspired the state's highway system, the Pearman Bridge opened on April 29, 1966. Their replacement span, the cable-stayed Arthur Ravenel, Jr. Bridge opened to traffic on July 16, 2005. Demolition of the Grace and Pearman bridges began shortly afterwards and was completed in late 2007. A very popular 10k run over the river occurs each spring, the Cooper River Bridge Run.
Though both bridges are modern in every respect, the Holt and Ravenel bridges are only two bridges to carry motor vehicular traffic across the river, although the Dennis C. Bishop Bridge carries US 52-US 17 Alternate traffic across the Tail Race canal just below the Pinopolis Dam on Lake Moultrie.
A CSX railroad trestle bridge traverses the upper reaches of the West Branch, below the Pinopolis Dam.