Overview
Lake Marion is the largest lake in South Carolina, covering roughly 110,000 acres across the state's central coastal plain in Clarendon, Orangeburg, Berkeley, Calhoun, and Sumter counties. Often called the state's "inland sea," it was created in the early 1940s when the South Carolina Public Service Authority (Santee Cooper) dammed the Santee River as part of the Santee Cooper Hydroelectric and Navigation Project, a Depression-era effort to bring electricity and jobs to rural South Carolina. Santee Cooper owns and operates the reservoir primarily for hydroelectric power, water supply, navigation, and recreation.
With approximately 315 miles of shoreline, Lake Marion is a broad, shallow lowland reservoir averaging only about 13 feet deep, though old river channels near the Santee Dam reach the mid-70s. Its defining feature is flooded bottomland forest: standing cypress and tupelo, submerged stumps, creek arms, and the wildlife-rich Sparkleberry Swamp at its upper end. This stump-filled, vegetated character makes navigation demanding in places but creates exceptionally productive fish and wildlife habitat throughout the lake.
Lake Marion is one of the Southeast's premier fishing destinations, long famous for landlocked striped bass along with largemouth bass, crappie, bream, and trophy catfish. Fisheries are managed by the South Carolina Department of Natural Resources (SCDNR), which operates several wildlife management areas around the lake alongside the Santee National Wildlife Refuge. Public boat ramps, marinas, campgrounds, and Santee State Park provide broad access, drawing anglers and boaters from across the region.
Water levels on Lake Marion are managed by Santee Cooper under a FERC-licensed rule curve, with a normal full-pool target near 76.8 feet above mean sea level. The lake is directly tied to Lake Moultrie downstream through the 6.5-mile Diversion Canal, and the two are operated together as the Santee Cooper Lakes to balance power generation, water supply, and recreation. Seasonal rainfall, drought, and hydro operations influence elevations, so monitoring current lake levels is important for boating safety, fishing, dock access, and shoreline activities throughout the year.
Current Conditions
Lake Marion is currently 2.88 feet below full pool and has fallen slightly over the past week.
- 7-day trendFallingLatest movement can differ from the seven-day trend.
- 7-day changeDown 0.01 ft
- 30-day changeDown 0.07 ft
- Drought conditionsModerate Drought
About This Lake
Learn how this lake is managed, what affects its water level, and where Lake Insights gets its data.
Lake Marion is a 110,000-acre reservoir on the Santee River (Wateree and Congaree Rivers) managed by Santee Cooper.