Coonamessett

Overview

The Coonamessett River, the third largest groundwater fed stream on Cape Cod, flows approximately three miles from Coonamessett Pond to the Great Pond estuary and farther out into Vineyard Sound. One of the Spring Sapping valleys of Falmouth, the river formed ~15,000 years ago during the last glacial retreat. In colonial times, the hydrology and water chemistry of the valley changed due to a succession of grist and woollen mills, the construction of cranberry bogs, and most recently, residential development. The river and River Herring, the diadromous fish who use the river to migrate to and from their spawning habitats, encountered 3 structural barriers in addition to the sand, ditches, and berms of the former cranberry operations. Namely the Lower bog Dam, the John Parker Road culvert, and the Middle Dam.

In an effort to combat the decline of the river’s aquatic habitat and increase successful River Herring migration, concerned citizens together with public and non-profit organizations began to lobby and promote conservation of land on both sides of the river. The 300 Committee, the town’s land trust, purchased (or helped the Town of Falmouth purchase) the land, what is now the Coonamessett River Heritage Trail. In parallel, the Coonamessett River Trust (CRT) provided biological and chemical monitoring of the river system which continues today. Ultimately, the Town of Falmouth purchased three downstream cranberry bogs and, in 2009, partnered with Massachusetts Fish and Game’s Division of Ecological Restoration (DER) to make the restoration of the Coonamessett River a DER priority wetland restoration project. An express goal of the restoration was to ensure safe passage for American Eel, River Herring, and Brook Trout.

From 2009-2015 the Town obtained small grants from Fish America Foundation and the Massachusetts Environmental Trust to support the planning process. In 2016, the Town received a large grant from the National Oceanographic and Atmospheric Administration (NOAA) to begin implementing the wetland restoration.

The wetland restoration project was realized in two phases. Phase 1 was completed in 2018, and included the removal of the Lower Bog dam, the reconstruction of the river channel, the restoration of 17 acres of wetland, and the installation of a boardwalk and bridge. Phase 2, completed in 2020, included the removal of the Middle Bog dam, installation of a public access boardwalk, and restoration of 39 acres of wetland across the former cranberry farm growing surface. This phase of the restoration was partially funded by an MVP grant, and included the replacement of three failing culverts, which will allow migratory fish to access their upstream habitat, including the 158 acre Coonamessett Pond.

The Coonamessett Wetland Restoration was developed with the intent of supporting the needs of the community and public engagement with the land. The establishment of a naturalized, self sustaining river system provides long-term climate adaptation benefits. Replacement of undersized failing culverts improved the road system. In parallel, the Town took advantage of opportunities for people of all ages to enjoy the restored landscape and learn about nature. In 2018, the Coonamessett River Heritage Trail was established to provide a network of public walking trails, viewing platforms, and outstanding interpretive signage that allows visitors to better appreciate the river, its history, and the benefits accrued to people and wildlife from its restoration. The restored river system provides free passage for migrating river herring and allows the CRT to expand its “Adopt-A-Herring” program..

Partners: The Town of Falmouth, The Coonamessett River Trust; The 300 Committee Land Trust; the Town of Falmouth, MA; MA Division of Fisheries and Wildlife Division of Ecological Restoration (priority project); Massachusetts Environmental Trust (MET); National Oceanic and Atmospheric Administration (NOAA); National Fish and Wildlife Foundation; USDA Natural Resources Conservation Service (NRCS); Massachusetts Vulnerability Program (MVP); MA Division of Fisheries and Wildlife; MA Division of Marine Fisheries; Association to Preserve Cape Cod; Cape Cod Conservation District; FishAmerica Foundation; Falmouth Rod and Gun Club; Stimpson Studio; Tighe and Bond; University of Connecticut; Woodwell Climate Research Center; InterFluve Inc. (project engineer); SumCo Ecological Services (construction contractor - restoration.)