The U.S. Army Corps of Engineers, partnering with the city of Stamford, Connecticut, is restoring the ecosystem of the Mill River under the authority provided by Section 206 of the Water Resources Development Act of 1996. The Mill River, which forms the lower two miles of the Rippowam River, runs through the center of downtown Stamford to its confluence with Long Island Sound in southwestern Connecticut.
By removing two concrete dams in 2009, the project reopened the free-flowing river channel to the Atlantic Ocean for the first time since the 1600’s, restoring anadromous fish passage to the Rippowam River watershed. The two dams blocked fish passage and tidal exchange and created a sediment-laden impoundment. Concrete walls bordering the impoundment eliminated riparian habitat and fill placed in intertidal marshes created low value common reed habitat (Phragmites australis) and degraded riparian areas overrun by invasive, exotic plant species. The project restored floodplains, riparian areas, and salt marsh habitats along the river corridor by removing the dams, walls and fill, creating channel habitats, and replacing exotic plant species with native species.
Removal of the Main Street Dam also reduces the 100-year flood elevation in portions of downtown, reducing the depth and extent of potential flooding in the city of Stamford. Restoration of aquatic habitats in the Mill River corridor also improves the human environment by restoring the natural settings of the City’s parks and improving outdoor recreational and educational opportunities.