The article on the Wave Dissipation System in the Sept. 15 issue of the Island Eye failed to provide information on the full impacts that the wall is having on the beach erosion and sea turtle nesting on Isle of Palms.
The Wave Dissipation System was installed as a temporary research project to determine whether the system would allow sand to build up behind the wall to prevent erosion and minimize scouring caused by the installation of more traditionally constructed walls or sand bags. Recently published reports from DHEC staff, who monitored the site along with an independent evaluator, clearly demonstrate that the Wave Dissipation System is ineffective at trapping sand and minimizing beach erosion. DHEC staff also concluded that the Wave Dissipation System has a “negative impact to fauna, flora, physical or aesthetic resources, beach access and adjacent properties.” Due to these findings, the U.S. District Court recently ordered that the walls be removed.
The court order cites evidence that these sea walls led to “persistent scour,” or local trenching at all sites. The walls were also found to block the natural movement of sand up the beach, leading to a decrease in the sand volume on the landward side of the sea walls. In fact, study after study throughout the past 50+ years has consistently shown that hard, or rigid armoring of beaches does not work. I live on Isle of Palms and visit the beach where the walls have been installed almost daily. I can verify that the findings of the report are consistent with my observations.
Unfortunately, the real impact of the Wave Dissipation System is not on the beach itself, but on the endangered sea turtles that try to nest on Isle of Palms every summer. In the article, Deron Nettles claims that the walls are “turtle friendly,” but without evidence.
The court found overwhelming evidence that the walls were causing harm to the sea turtle population. The court order, citing sea turtle expert Sally Murphy, who has served as the lead sea turtle scientist at the Department of Natural Resources for 30 years, reported that physical obstacles, such as sea walls, harm the sea turtles in several ways, including when turtles try to nest but are turned back because of obstacles. These “false crawls” are harmful to the energy reserves of the female sea turtles and to their reproductive productivity. The court found that the sea walls lead to a “significant impairment” in the sea turtles’ breeding patterns.
Nettles goes on to claim that the horizontal panels of the sea wall were removed to allow access by the sea turtles, but fails to acknowledge that this was only done after the court ordered them to be removed, in the last few days remaining of the nesting season.
Rising sea levels, increasing threats of hurricanes and naturally shifting shorelines will continue to tax our best efforts at preserving our beaches for both recreational enjoyment and for the sea turtles that rely on them to sustain their life cycle. Hard armoring of beach front property has never proven to be effective at stopping erosion. Beach re-nourishment combined with the restoration of a robust natural dune system may be our best short-term solution in protecting beachfront property and providing nesting habitat for sea turtles, who have been using these beaches for millennia.
Keith Bowers, Restoration Ecologist
Isle of Palms