Herring to Benefit from Dam Removals, Wetland Restoration in Coonamessett River

April 29, 2020

NOAA, the Town of Falmouth, and other partners are working to restore Massachusetts’ Coonamessett River. The projects will benefit alewife, blueback herring, and other migratory fish.

A river runs through a wetland

Phase I of the Coonamessett River restoration project was completed in 2018.

At barely more than three miles long, the Coonamessett River in southeastern Massachusetts may seem small. But, it was once home to one of the largest river herring runs in New England. Since 1700, dams and other barriers have blocked the migration of alewife, blueback herring, and other native fish species. NOAA has collaborated with the Town of Falmouth and other partners since 2006 to reopen the Coonamessett River. Our efforts will allow fish to access the habitat needed to sustain their populations.

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River herring in the Coonamessett River. (Photo: Coonamessett River Trust)

Historically, the Coonamessett River provided habitat for millions of migrating fish. Over time, however, the river was diverted and dammed. Its wetlands were converted into commercial cranberry bogs. These changes resulted in drastic declines in fish populations. By 2015, the annual river herring run had dropped to less than 75,000 fish. 

NOAA and many other dedicated partners have been working for years to remove dams and other barriers, restore native wetland habitat, and rebuild the river herring population. NOAA has contributed significantly—through both funding and technical assistance—to this ambitious effort. With funding from our Community-based Restoration Program, partners are:

Restoration work in the Coonamessett River is occurring in two project phases: 

  • Phase 1, completed in early 2018, included the removal of Lower Bog dam, installation of a public access boardwalk, reconstruction of the river channel, and restoration of 17 acres of wetlands. 
  • Phase 2, currently underway, includes the removal of Middle Bog dam and restoration of 39 acres wetlands by removing former commercial cranberry bogs. In addition, the replacement of three failing culverts with a large box culvert will allow migratory fish to access their upstream habitat, including the 158-acre Coonamessett Pond. 
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Phase 2 of the project is under construction, including the replacement of culverts under John Parker Road.

The project will reopen 2.2 miles of the river, restore 4,600 feet of the river channel, and rebuild 56 acres of wetland habitat. Public access trails and educational signage are also being constructed along the river, including two boardwalks and accessible trails. The project is expected to be complete later this spring.

Partners on this project include the Town of Falmouth, Coonamessett River Trust, Massachusetts Division of Ecological Restoration.

Last updated by Office of Habitat Conservation on April 29, 2020

Fish Passage