At its Dec. 16 meeting, Sullivan’s Island Town Council received a presentation from Ross Nelson of Westervelt Ecological Services outlining the planning, permitting and logistical challenges associated with dredging projects in the Lowcountry.
Nelson, who spoke in an unpaid capacity as a professional courtesy, has longstanding ties to the island. He has surfed on Sullivan’s Island since his college years and has founded and sold multiple consulting firms. Toler’s Cove Marina has been his primary dredging client for years and regularly uses the town’s confined disposal facility.
“It is not an easy process to go through,” Nelson said, referring to the permitting requirements associated with dredging.
Nelson explained that dredged material is typically handled in one of three ways: reused for a beneficial purpose, disposed of in a confined disposal facility, or barged offshore to a designated disposal site — a method he described as slow and costly.
Sullivan’s Island’s Sea Level Adaptation and Resilience Plan includes a recommendation to dredge Cove Creek and consider placing a thin layer of dredged sediment over nearby marshland as a beneficial use. Known as “thin-layer placement,” the technique raises marsh bed elevation and improves resilience to sea level rise.
The town currently owns a confined disposal facility, last rebuilt in 2008. Since then, it has been used once by the U.S. Army Corps of Engineers, more than four times by Toler’s Cove, and once by the National Park Service to clear access to a dock. If the town plans to use the facility again, Nelson said it will likely need to be rebuilt.
From feasibility studies to contractor selection, Nelson estimated the full dredging process typically takes between 18 and 24 months. One of the earliest and most critical steps is sediment testing, which determines whether the material consists of sand, silt or mud and whether it contains contaminants. This testing can take six to eight months and largely dictates how and where the material can be disposed of. Regulatory agencies generally will not begin permitting until the sediment analysis is complete.
Once permitting begins, the project must be reviewed by multiple agencies, including the Army Corps of Engineers, the South Carolina Bureau of Coastal Management, the Department of Natural Resources, the U.S. Fish and Wildlife Service, the State Historic Preservation Office, the National Marine Fisheries Service and the Environmental Protection Agency. All agencies must sign off before dredging can proceed.
Public input is also part of the process. The Army Corps issues a public notice for the project, and the town must address comments received during that period.
A bathymetric survey would also be required to determine how much material must be removed. Nelson estimated that more than 100,000 cubic yards of sediment could be dredged from Cove Creek.
“The easiest part of dredging is removing the mud,” Nelson said. “The hardest part is figuring out where to put the mud.”
Approximately 200 acres of marsh could potentially be used for thin-layer placement. However, the technique is still relatively new in South Carolina, having been used only once near Beaufort. As a result, additional studies may be required, potentially lengthening the permitting timeline. While states such as New Jersey and regions near Baltimore have used marsh-building techniques for years, Nelson cautioned that available marsh acreage may not be sufficient to accommodate the full volume of dredged material.
He also emphasized that dredging would not be a one-time effort. Cove Creek will continue to accumulate sediment over time, requiring ongoing maintenance.
“There’s no way to know if it’s every five, 10 or 40 years,” Nelson said, “but it’s going to be an ongoing process you will have to commit to.”
Mayor Pro Tem Justin Novak asked about risks associated with the project. Nelson cited sediment quality as a primary concern, noting that material with too much sand would provide limited benefit to the marsh, which requires finer silt. He also warned that placing sediment too thickly could inhibit vegetation from reestablishing.