Henlopen Acres looking to dredge marina

If everything goes as planned, about 4,500 cubic yards of material will be dredged from the Henlopen Acres marina soon after the U.S. Army Corps of Engineers dredges the Lewes-Rehoboth Canal at the end of this year.

Present conditions make it very difficult, sometimes even impossible, to navigate during low tide, said Town Manager Anna Fagan. It's important the town address this issue so slipholders can fully enjoy their boats, regardless of the tides, she said.

The state’s Division of Water issued a public notice March 11 related to the town’s desire to conduct maintenance dredging in the marina, which has 58 slips and is known as the Thomas B. Lewis Marina.

According to a report included with the public notice written by town consultant Envirotech, the excavator will operate from a work barge, temporarily placed within the marina.

The application says the dredged material will be placed in the newly constructed dewatering chamber, positioned in the open field next to the marina. Once the material settles and excess water is removed from the chamber, the spoils will be placed in dump trucks for offsite disposal at Delaware Solid Waste Authority’s Jones Crossroads Landfill in Georgetown.

However, said Fagan, the town is revisiting this method and exploring alternatives. The town is also exploring alternative disposal sites due to the significant costs associated with transportation and tipping fees, she said in an email March 16.

The report says the composition of the dredged material is 20% to 27% sand, 45% to 52% silt and 28% clay. The dredging and material disposal will be done during the winter to avoid state and federally regulated seasonal time restrictions, and to minimize wildlife and fish disturbance, said the report.

The town’s marina dredging coincides with a much larger dredging of the canal that the Army Corps of Engineers is expected to do this coming fall. That contract calls for dredging about 90,000 cubic yards of sediment from an area near the Freeman Highway bridge in Lewes to the entrance of the canal at Rehoboth Bay.

The town’s marina was last dredged in 2022. About 3,000 cubic yards of silt were removed at a cost of $170,000. 

Prior to that, the marina was dredged in 2012, removing 4,000 cubic yards of spoils at a cost of $200,000. Those spoils were placed in geo-tubes on the grassy area by the marina where they drained before the spoils were hauled away by truck to private farmland in the Broadkill Beach area.

The silting-in of the Henlopen Acres marina isn’t a new issue. A study done in 2019 showed the marina’s sedimentation rate has nearly tripled since the 1990s – about 360 cubic yards of sediment per year entered the marina basin from 1990 to 2003; 444 cubic yards per year from 2003 to 2012; and more than 900 cubic yards per year from 2012 to 2019. The study showed the marina lost 1 foot of depth from 2018 to 2019 and concluded that the town would need to dredge 6,505 cubic yards of sediment to achieve 4 feet of clearance at low tide.

“Unfortunately, silting has always been a struggle,” said Fagan.

Thomas B. Lewis was a World War II veteran and the former mayor and a commissioner for over a decade, from 1989 to 2001. Under his administration, a new town hall and maintenance buildings were built, the town's roads were completely repaved and the marina was rebuilt. The marina was named in his honor in 2000.

The state is taking comments on the proposed dredging until Tuesday, March 31. Submit all written comments or requests for a public hearing by email to Wetlands_LegalNotice@Delaware.gov.