Shaped by the wind, ocean currents and storms, coastal barrier islands are a slow-motion lesson in how small changes make big ones over time. You can see this lesson at work when you leave a towel on a windy beach, only to find it covered with sand grains minutes later. These grains add up. Every year, enough sand to fill Williams Bryce Stadium moves past any given spot off a barrier island beach, said Miles O. Hayes, a noted seashore geologist who studied the area.

Kiawah Island, the scene of a new battle over barrier island development, is no exception to these forces and for the most part has benefited from them. Unlike like Folly Beach, which has seen front-beach streets claimed by the waves during the past 80 years, Kiawah is generally gaining new beach, particularly at the southwestern end near the county's Beachwalker Park.

Because of this, the island's developer, Kiawah Development Partners, plans to build 50 homes on a mile-long spit that has grown to about 150 acres over the past few decades.

As part of this project, the developers hope to build a half-mile-long concrete revetment on the river side of this spit to prevent what nature has done on occasion over the centuries — cut through to the ocean and flush sand toward Seabrook Island's beaches.

But some property owners are girding for a fight, arguing that the public didn't have a real opportunity to review and comment on what they see is a major erosion-control project in an extremely sensitive area. Some say it's folly to build on such a pristine and vulnerable spot in the first place.

Kiawah Development Partners officials, meanwhile, have been stung by the criticism, saying the beach is stable, and that they have a long and respected record of doing development in an environmentally responsible way. "I always thought we were doing a good job out here," said Leonard Long, executive vice president.

'Curves of sand'

Hayes is chairman of Research Planning Inc. in Columbia and for the past 50 years has studied coastlines around the world. In the 1970s, a Kuwaiti investor owned Kiawah Island and hired Hayes' company to recommend "setback lines," boundaries where a developer might safely build structures.

During this research, he and his colleagues discovered what might be called the Capt. Sam's Shuffle.

First the sand moves south along Kiawah and builds up the spit. "If you look at an aerial picture, you can see curves of sand forming at the southern end, and each one of those curves represents a pulse of growth, like a tree ring," Hayes said.

Then as the beach grows longer, the Kiawah River begins to eat into Seabrook Island — until a storm or tide cuts through the spit and the process begins anew. "It usually goes in 40- to 50-year cycles," said Hayes, who along with his wife, Jacqueline Michel, wrote a new book, "A Coast for All Seasons."

Hayes said that because of these forces, he recommended in the early 1980s that the split be cut about two-thirds of the way to help nourish and protect Seabrook's beaches. Crews did this in 1983, and Seabrook soon had 1,000 feet of new beach. The spit was cut again in the 1990s. "It worked like a charm."

Hayes said he also told Kuwaiti investors that developing the area around Capt. Sam's Inlet didn't make sense because of the shifting sands and inlet, and that the entire area should be set aside as a park.

The Kuwaitis leased 2 acres near the spit's neck to Charleston County for 99 years to create Beachwalker Park, but the rest of the spit remained in private hands and undeveloped.

"All these years I always thought the whole spit was a park," Hayes said, adding that he was surprised to learn that Kiawah Development Partners wants to build homes on the spit. He said it was a bad idea in the 1970s and remains so today. "I'm appalled that they want to develop that spit. Ridiculous. Stable? It's one of the most unstable places on the East Coast."

Outcry grows

Long of Kiawah Development Partners finds it equally ridiculous when people say the beach is unstable.

He said that more recent and detailed research than Hayes' work shows that the spit has grown dramatically in recent decades and now has dunes that are just as high as those on other parts of the island where homes were built. Long also pointed to DHEC's 2008 "State of the Beaches Report," which shows that the dunes on the western end of Kiawah have been stable in recent years. "The beach grows 15 feet a year," Long said. "This is an enormous piece of land compared to what it was."

In a position paper answering the project's critics, Kiawah Development Partners said many hurricanes hit the area over the past 60 or 70 years, including Hugo in 1989, and none of them cut a permanent inlet through the spit.

"Much to the contrary," the company's position paper said, "the Kiawah spit overall has been so stable and building at such a rate, that the town of Seabrook Island and its coastal geologists had to 'relocate' the inlet in the 1990s through explosives and digging. ... Likely few other coastal areas on the eastern seaboard of the United States have had continuous accretion for six or seven decades. This is hardly the 'fragile' piece of land some have suggested."

The plan to build on the spit has been in the works for years. Kiawah Development Partners had zoning approval for hundreds of houses. But in 2005, the company agreed to build fewer than 50 homes on 20 acres. The agreement was part of a larger agreement covering the whole island and generated little controversy at the time.

That changed this summer when U.S. Rep. Henry Brown, R-S.C., introduced a bill to remove the spit from the Coastal Barrier Resources System. That would make the spit eligible for federal flood insurance.

Brown's bill triggered an outcry from people who said the government shouldn't subsidize people who build in vulnerable undeveloped beach areas. As opposition grew, Brown decided to kill the bill.

But the debate also focused attention on Kiawah Development Partners' plans to develop the spit and build the half-mile-long revetment. Like Hayes, some property owners on Kiawah thought the area would remain undeveloped. Many hadn't heard about the revetment project, either.

During a meeting Tuesday at Kiawah's Town Hall, several people argued that the revetment would ruin a prime habitat for declining numbers of the diamond-back terrapin and other wildlife. Several urged the town to ask the state to delay a decision on the revetment's permit because property owners hadn't had a chance to review and submit comments on the project.

Kiawah Development Partners did place a public notice in The Post and Courier on May 21 about its application to build "an erosion control project along the Kiawah River at, and on both sides of Beachwalker Park." The public had 10 days to comment.

The notice had no other details about the project's scale, but Long said his company submitted several pages of facts, specifications and graphics to the town, and that council members were told about the project.

Long also said the revetment would be made of small concrete donuts that allow plants to grow through the holes and give the structure a more natural appearance. Erosion already is affecting the Beachwalker Park parking lot. "We and Charleston County taxpayers will lose land and have to repair park improvements if we don't stop the river erosion," he said, adding that the town of Seabrook and its property owners association have no objection to the revetment. A letter from the property owners association said its consultant "does not believe that any such armoring will modify Cap'n Sam's Inlet, its hydraulics, or migration cycles."

The state Department of Health and Environmental Control is set to decide soon whether to give Kiawah Development Partners a permit for the revetment. "We're proceeding with the standard review process, and there will be no public comment or public hearing," said Dan Burger, communications director for DHEC's office Ocean and Coastal Resource Management.

Beach is growing

This debate about the future of a relatively small portion of Kiawah mirrors a deeper debate looming about the merits of building at the sea's edge when scientists predict the sea will rise dramatically during the next five decades. Scientists have estimated that a one-foot rise will erode about 100 to 200 feet of beach in South Carolina. Some coastal geologists have proposed plans to help barrier islands migrate away from the sea by building up the islands' backsides. Others say it's futile for man to try to fight off the sea.

Hayes said a revetment on Kiawah likely will stop nature from taking its course in the short term, at least as far as having the Kiawah River breach the spit's neck.

"If you want to spend the money, it will work in the small storms." As far as the long term is concerned, he said, "I wouldn't want to put a house out there."