South Carolina’s top environmental board said it wants at least another year of study for an experimental seawall that’s being tested as a way to prevent severe erosion along parts of the coast.
The Department of Health and Environmental Control (DHEC) board went against its own agency staff — who had recommended removing the “Wave Dissipation Systems” (WDS) at spots on Isle of Palms and Beaufort County. The system is being piloted as a way to protect condos and beachhouses instead of sandbags. But environmental groups have filed legal action, saying the devices violate the state’s ban on seawalls and can prevent endangered sea turtles from nesting.
But the agency staff also disagreed with the Citadel professor who was acting as the project’s lead researcher, as well as an independent engineer who was hired to review the tests. In the end, board members seemed frustrated by the disagreement over measurable findings. “Clarifying what you’re measuring and how you’re going to measure it is a basic during a design experiment,” board member L. Clarence Batts, Jr., said. “And I didn’t hear or see anything in this report to indicate that was done in a formal way.”
The Citadel had been testing the WDS devices at locations on the Isle of Palms in Charleston County and Harbor Island in Beaufort County. Last September, DHEC staff concluded the study had been unsuccessful and was not able to slow severe erosion on those beaches — and may have even been making it worse. But the company which makes the devices and residents of the impacted buildings appealed to the board, arguing DHEC had not allowed researchers to move the system up and down the beach as conditions changed — which they say was its intended use.
“Nothing can stop erosion. Erosion is going to happen,” said attorney Matt Hamrick, who is representing WDS inventor SI Systems, LLC. “What we’re trying to find here is something to give time for the properties to be safe and for the beach and dunes to have more time.”
Blair Williams, who manages the critical area permitting at DHEC’s Office of Coastal Resource Management, said the WDS does blunt the impact of waves, but that energy is redirected and can cause worse erosion either along the wall’s base or elsewhere along the shoreline as a result.
“We think it dissipates the wave energy to an extent, but it does not dissipate wave energy to the extent that it addresses an erosional issue,” he told the board on Thursday.
Conservation groups say they can understand why island residents would want the walls to work, but they believe the environmental impact is too severe. The organizations say the devices have the same erosional impact as seawalls, even if only on a temporary basis. The South Carolina Environmental Law Project and the SC Wildlife Federation have said they will file a lawsuit if the devices are not removed. The groups have also revealed photographs of sea turtle “false crawls,” which indicate the animals came ashore to lay their eggs but returned to the ocean without nesting — a potential violation of the federal Endangered Species Act.
But supporters maintain the WDS is not a seawall because its plastic walls can be removed and moved along the beach as needed.