The I-526 or the “Mark Clark Expressway” is an interstate in Charleston County that runs from West Ashley to Mount Pleasant. Charleston County is proposing to extend the highway from the current terminus at Savannah Highway onto Johns Island and over to James Island to connect to the James Island Connector.
This project would displace homes and businesses, destroy over 38 acres of saltwater and freshwater wetlands, impact over 30 acres of James Island County Park, and escalate suburban sprawl on rural Johns Island.
The impacts to wetlands would be greater than predicted in previous environmental assessments for the project.
The construction impacts are far-reaching and would be felt heavily throughout communities around the Charleston area for years to come.
Destruction of wetlands and other important waterways
The proposed I-526 Extension would cut through marine ecosystems and freshwater wetlands that are integral to water quality in the already-impaired Stono River. The proposed route would destroy over an initial 38 acres of wetlands and other waters of the United States, including freshwater, wetlands, ponds, and tidal salt marshes with further wetland destruction overtime from the impacts of pollution and runoff from the roadways. Furthermore, the bridges will interrupt the shoreline, shadowing the marsh underneath and effectively killing it.
Wetlands provide important ecosystem services to nearby communities through flood storage and wave buffering; that role has become increasingly valuable in light of the region’s recent exposure to storm hazards, which is only projected to worsen due to climate change. Wetlands also provide wildlife habitat, fish nurseries, water purification, erosion control, food supply, and carbon storage.
Susceptibility to future flooding
The proposed I-526 Extension crosses a low-lying coastal ecosystem. Portions of the project close to sea-level could be exposed to several feet of water with even a low-level hurricane. Within the next decade, we could also see effects from tidal flooding in certain areas. Taking into account sea level rise, portions of the road may be underwater by the time the road is built.
Restriction of access to existing natural and recreational spaces
The proposed I-526 Extension will destroy 30 acres of James Island County Park, which includes a climbing wall, bouldering wall, challenge and ropes course, park headquarters building, public access to a creek, over three acres of park wetlands, habitat for plants and wildlife, and parts of the disc golf course, campground and associated cottages.
Extending brings more development pressures
The I-526 Extension will induce additional suburban development in rural areas of Johns Island which will make traffic congestion worse and lead to additional impacts to wetlands and other critical natural resources. We saw this happen dramatically in Mount Pleasant when I-526 was extended across the Cooper River in 1992.
Displacement and disturbance of community health and well-being
The 526 Extension will disproportionately impact environmental justice communities. The proposed route bisects or borders seven census blocks with disproportionately low-wealth or minority residents. Residents along the route will either be forced out of their homes or subjected to significant and harmful air, water, and noise pollution.