KIAWAH ISLAND — The developers of this gated beach golf resort want to sink a wall in the sand of Sam's Spit, but environmentalists oppose the move, saying it's a back-door attempt to build a bulkhead that regulators already denied.

This is the undeveloped strip of sand and dunes past Beachwalker Park on the island's west end toward Seabrook Island. An attempt to build a half-mile-long concrete wall along the inlet bank to stem erosion in 2008 was hotly contested. State regulators denied the permit, instead allowing a 270-foot-long bulkhead.

Public attention first focused on the spit earlier last year, when U.S. Rep. Henry Brown, R-S.C., wanted to change a federal law so potential homeowners on the spit could get an insurance break.

"It's the same permit South Carolina Ocean and Coastal Resource Management already rejected," said Katie Zimmerman, Coastal Conservation League project manager. "It has all the same issues."

"That's not correct," said Trenholm Walker, an attorney for the Kiawah Development Partners, to whom questions were directed. He characterized the sheet pile construction as a revetment, essentially a retaining wall designed to hold sand in place. It would be dug into the high ground away from the water.

"It's a reasonable step being taken by the property owner to protect his property against the 1-in-100 chance that (a storm over-wash) will happen," he said.

One way or another, the permit application filed with the state by the partnership is unprecedented.

"It seems to be unique. We've probably never gotten one like it before," said Adam Myrick, media relations officer for the S.C. Department of Health and Environmental Control. Ocean and Coastal Resource Management is a division of DHEC.

Although it looks to be part of Charleston County's Beachwalker Park, the 150-acre Sam's Spit is owned by the partnership and has enough high ground that as many as 50 homes could be built there. It's shaped like a yellow squash, with a narrow neck near the park that widens to a broader stretch.

Developers want to set a 1-foot-wide corrugated metal wall five to 10 feet deep in the sand for 300 to 350 feet through that narrow neck. It would rise about a foot above the existing surface. The permit being sought is approval for the plans to deal with stormwater discharge from the road built to do the work. Myrick could not immediately say what the road would be made of, but said the presumption is it will be an improved surface such as gravel or pavement.

"The property owner is well within his rights. It's not in the critical area," Walker said. Developers plan a low-intensity, environmentally sensitive development that's not expected to be as many as 50 homes. "The sand is accreting, the beach is increasing, the dunes are growing, the vegetation is marching toward the spit. This is a stable beach."

The development's own environmental analysis, conducted in the 1970s, contradicts that, said Amy Armstrong, a South Carolina Environmental Law Project attorney. The analysis characterizes the spit as extremely unstable and "subject to rapid and drastic changes in erosion and deposition." The analysis was done by Environmental Research Center in Columbia.

The sheet pile is an attempt to stabilize the shoreline just like the bulkhead, Armstrong said. "If that structure goes in, it's going to facilitate development. OCRM has to look at the long-term and cumulative effects of that. This is a fragile and sensitive area. If it's stable, then why do you need a structure to prevent erosion?"