Emergency dredging begins at Indian River Inlet: How we got here

After the Atlantic Ocean breached the dunes and washed onto the coastal highway several times earlier this year, emergency dredging is finally underway to replenish the severely eroded beach on the state park’s north side of the Delaware Seashore.

The project will dredge up to 400,000 cubic yards of sand from the flood-prone shoal of Indian River Inlet, just west of the Charles W. Cullen Bridge, to replenish up to 5,000 linear feet of the beach at the north side, a Department of Natural Resources and Environmental Control ” said the press release. The dredged material will be screened and then transported by pipeline to the north side beach, where it will be leveled.

The reconstructed dune will be 25 feet wide and 16 feet high, the press release states, while the beach will be approximately 100 feet wide and 9.2 feet high (about 7 feet above average high tide). . Resupply will begin along the pier and extend north.

The beach on the north side should remain closed for the duration of the restocking. Mariners are asked to use caution in the creek area and maintain a safe distance from dredging equipment.

Why emergency restocking is necessary

The Indian River Inlet area on the Delaware coast is very complex. The inlet serves as a connection between the Atlantic Ocean and Indian River and Rehoboth bays. The coastal road, a critical evacuation route, crosses the cove via the Charles W. Cullen Bridge. On either side of the bridge, the road crosses narrow strips of land between the ocean and the bays.

The dunes provide the coastal route’s only protection from the Atlantic, and they have been breached several times this year on the north side of the cove. Although the flooded highway area is at the base of the bridge, officials from the Department of Natural Resources and Environmental Control and the Department of Transportation said the bridge itself poses no risk.

The beach on the north side is particularly susceptible to erosion because the jetties on either side of the cove interrupt the natural flow of sand. Sand generally flows north, but at the entrance, sand blocked by jetties accumulates on the south side.

For years, the Department of Natural Resources and Environmental Control relied on a diversion system to pump sand from the south side to the north side. Although the bypass was never intended as the only solution to erosion on the north side, department officials said, it broke down in 2019.

The decision was made to convert the pump from diesel to electric, but the pandemic hit and delays ensued. The bypass system is expected to finally be repaired next year, but since 2019 the department has spent at least hundreds of thousands of dollars trucking sand north. It wasn’t enough to keep up with the erosionand it wasn’t either the decision to use riprap to fortify the dune.

The only option left was dredging and resupply. The Department of Natural Resources could have requested federal funding for restocking from January 2023, according to John Kane, infrastructure director for the US Senate Committee on Environment and Public Works, but the first time they did it was in May of this year, and that request was denied, according to the spokesperson for the Ministry of Natural Resources, Nikki Lavoie.

It took a dune failure in August, the second of the year, for the state to release $15 million in emergency funding. Shortly after Governor John Carney made the announcement, U.S. Senator Tom Carper announced $10 million in federal funding to “implement a long-term plan to secure the dunes and protect the infrastructure surrounding the Indian River Inlet Bridge.”

The U.S. Army Corps of Engineers has accelerated the permitting process and is now expected to conduct additional dredging and replenishment work at the Delaware Seashore in 2025, the DNREC press release states.

Shannon Marvel McNaught reports from southern Delaware and beyond. Contact her at [email protected] or on Twitter @MarvelMcNaught.