Folly Beach Mayor Tim Goodwin worries that the project to make Charleston Harbor better for shipping will leave the island scarred due to erosion and lost sand.
"That's what we are afraid of, that it's not going to be a good thing for Folly Beach," he said Friday.
The Army Corps of Engineers has offered a plan that includes extending the shipping channel entrance three miles seaward. Goodwin fears that will affect offshore currents that carry sand to Folly. For that reason, more study of the situation is needed, he said.
Otherwise, the city will consider legal action to challenge permits for the project, he said in a recent letter to the Corps.
Goodwin said Friday that he does not want to delay the harbor-deepening project. However, the Corps should analyze how the work could affect Folly Beach.
He is calling for a Regional Sediment Management Study to see if the project might be managed to Folly's benefit.
"We ask the Corps and the Port to recognize that the harbor causes substantial harm to Folly Beach and it is unfair for our citizens to bear that burden for the state." The harbor improvement project "will only amplify those effects, and we would like to reach an agreement on mitigating those harms," Goodwin wrote.
Up to 12 million cubic yards of material dredged for harbor deepening may help Folly if it is put near shore south of the jetties instead of farther at sea as currently planned, Goodwin said.
Or the Corps could explore creating a way for southerly sand flow to continue around the three-mile-long jetties instead of stacking up at the north jetty, he said.
The Army Corps and the State Ports Authority had no comment Friday on Goodwin's concerns. The SPA referred questions to the Corps, which said that it will respond to Goodwin's issues in its final report and recommendation on the project.
His two letters to the Corps are among 700 public comments received for the harbor deepening project's Draft Integrated Feasibility Report and Environmental Impact Statement. It suggests deepening the major shipping channels within the harbor from 45 to 52 feet at an estimated cost that would be shared between the federal government and the SPA at $166 million and $343 million, respectively.
Because science has shown that the jetties cause beach erosion on Folly, the federal government has funded 85 percent of multi-million dollar beach renourishment efforts on the island. Last year, Folly had a $30 million beach restoration project.
An estimated 57 percent of the erosion on Folly happens when the jetties block the southerly flow of up to 152,000 cubic meters of sand yearly. Because of the jetties, used for shipping channel stabilization, offshore shoals have lost roughly 200 million cubic meters of sand resulting in a 100 percent increase in wave energy, according to a study referenced in a Goodwin letter to the Corps.
The recognized connection between the jetties and Folly erosion led to an agreement between the city and the federal government for a periodic 50-year renourishment project that began in 1993.
The harbor-deepening project will make the port better able to handle the largest ships. Charleston Harbor is the fourth busiest East Coast port for container cargo traffic.
The project includes deepening the existing entrance channel from 47 feet to 54 feet and increasing the depth of the inner harbor from 45 feet to 52 feet. The diameter of ship turning basins would be enlarged.
Reach Prentiss Findlay at 937-5711