During the Sullivan’s Island Town Council meeting on Tuesday, April 15, Steven Traynum of Coastal Science and Engineering (CSE) announced that the town’s dune restoration project—completed in partnership with the U.S. Army Corps of Engineers (USACE)—was officially finished. He also offered suggestions for similar projects in the future.
Carried out between Nov. 28 and March 6, the dune restoration was part of a USACE beneficial use program designed to enhance beach stability and storm protection. Approximately 220,000 cubic yards of sand were placed on the beach by the USACE at no cost to the town. Instead of transporting the sand to a distant disposal site, the Corps strategically deposited it along low-tide areas of the island, allowing natural wave action to cleanse the sand of muddy sediments, leaving behind higher-quality material.
A key uncertainty at the project’s start was the retention of sand near Breach Inlet, where strong currents could potentially carry sediment out to sea. However, Traynum expects any displaced sand to naturally migrate back to the beach as a shoal over time, remaining within the system and reinforcing the beach—even if the impact isn’t immediately visible.
The Army Corps placed roughly 2,000 cubic yards of material per day. Initial attempts to use conveyor systems slowed progress and ultimately proved problematic. The switch to trucks moving sand directly in front of dredging equipment significantly improved efficiency.
The town supplemented the Corps’ efforts by relocating 76,000 cubic yards of sand from the low-tide line farther inland to reinforce dunes and build berms. This work focused on areas without seawalls, enhancing storm protection for high- and mid-tide beach zones. In total, 2,600 linear feet of dunes were restored.
Additionally, Sullivan’s Island strategically stockpiled 1,500 cubic yards of beach-compatible sand for future discretionary use, eliminating the need to purchase and transport additional sand—a typically expensive proposition.
Looking ahead, Traynum recommended that future USACE placements deposit sand higher on the beach for better retention. He also suggested the town invest $20,000 to $30,000 in vegetation—such as sea oats or grasses—to stabilize dunes, ideally planting during the cooler, wetter spring or fall seasons to ensure successful growth.
“I believe the Corps expanded these disposal areas within the waterway specifically to reserve them for unsuitable materials like pluff mud,” Traynum explained. “Beach-quality sand will be directly dredged from the channel and placed on the beach in the future, substantially improving productivity.”
Traynum anticipates similar restoration projects every three to four years and reassured council members that funding should remain consistent, noting that these efforts are fundamentally tied to navigational improvements along the waterway.