Dam Removal Project Restores Natural Flow For Fish In Brandywine River

Deconstruction at the DuPont Dam on the Brandywine River, a project expected to reduce flooding and improve water quality. (Photo courtesy Brandywine River Restoration Trust)

Deconstruction at the DuPont Dam on the Brandywine River, a project expected to reduce flooding and improve water quality. (Photo courtesy BRRT)

WILMINGTON — The Brandywine River Restoration Trust (BRRT) began removing part of the DuPont Experimental Station Dam, also known as Dam 6, a major step in an effort to restore natural fish passage along the Brandywine River.

The project will reconnect an 11-mile stretch of river, opening it to migratory species such as American shad for the first time in nearly 300 years.

Restoring a natural flow

“Removing unused or deteriorating dams restores the natural, original flow to rivers and streams,” said DNREC Secretary Greg Patterson.

Built in 1839 by E.I. du Pont de Nemours to power a series of mills, Dam 6 is jointly owned by the City of Wilmington and DuPont. Though long inactive, it has contributed to periodic flooding at the Experimental Station after heavy rains.

“With the removal of Dam 6 on the Brandywine, DNREC scientists expect less local flooding, increased habitat for native fish and aquatic species, and improved water quality – all good things,” said Patterson.

Welcoming shad

Like salmon, shad are anadromous-born in fresh water, spending most of their lives at sea, and returning to rivers to spawn. After the first Brandywine dam removal in 2019, University of Delaware Sea Grant researchers documented American shad spawning in the newly opened habitat just a year later.

“Large schools of shad used to swim up the Brandywine every year,” said Professor Ed Hale of UD-Sea Grant. “We’re on our way to welcoming them back through reconnecting fragmented habitat corridors.”

A study by The Nature Conservancy has identified the Brandywine as one of the six highest-priority tributaries of the Delaware River for shad restoration.

Dam removal

The removal of Dam 6 reflects a broader national trend. In 2024, a record 108 dams were dismantled across the United States, according to American Rivers. Advocates point to benefits beyond fish passage, including improved water quality, reduced flood risk, and increased biodiversity.

While the majority of the dam will be taken down, one-third of the structure will remain intact as a public exhibit. BRRT plans to highlight the industrial history of the Brandywine through interpretive panels, guided tours, booklets, and presentations.

“These programs will help Delawareans understand the remarkable history of the Brandywine dams and the mills they powered,” said Jim Shanahan, Executive Director of BRRT.