New Port Construction Leads to Salt Water Wetland Creation

The South Carolina Ports Authority is planning to develop a marine container terminal at the south end of the Charleston Naval Complex (CNC), on the Cooper River, in North Charleston, SC. The agency has worked diligently to avoid, minimize and mitigate impacts associated with the construction of this terminal through an extensive EIS process that identified multiple mitigation measures now being implemented. A major element of the mitigation process is the creation of over 22 acres of new intertidal wetland habitat on a former dredged material disposal site (DMDS) located on the southern end of Drum Island in Charleston Harbor. This collaborative project included ecological planning, environmental research/permitting, soil & contaminant testing and coastal & marine engineering to plan and design a sustainable habitat that would withstand the weather and tidal conditions prevailing at the site. As Drum Island is a former DMDS, a sediment assessment of the project site is being implemented at the request of the US Army Corps of Engineers. The assessment will ensure potential contaminants that may be exposed after the highland is excavated will not be released into the adjacent waters. The project's engineering challenges stem from Drum Island's central location in Charleston Harbor. With an over 7 km fetch the site is exposed to severe wind and wave action in addition to strong tidal currents. Engineering studies were performed to develop a combination of natural and traditional shore protection measures are being employed to protect this new state resource. This salt water wetland restoration project is one of the largest of its kind in South Carolina and will not only serve to provide direct mitigation for wetlands impacted by terminal construction efforts, but will also provide essential habitat for many native plant and animal species. The completed restoration site will be inclusive of low lying spartina marsh, mid level marsh, vegetated upland areas and meandering tidal creeks complete with oyster habitat and shell banks.