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 woolen mills, the construction of cranberry bogs, and most recently, residential development. The lower one mile of 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, the Lower bog Dam, Middle Berm, and the John Parker Road culvert.
Conservation: acquiring and monitoring the floodplain
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 Town of Falmouth purchased the lower river bogs (Lower, Middle and Upper Bogs) in 1971 and leased the bogs for cranberry cultivation. In the early 2000s, the 300 Committee, the town’s land trust, purchased (or helped the Town of Falmouth purchase) additional land that bordered the river along the entire three-mile length, creating the Coonamessett Greenway, where, Coonamessett River Heritage Trail is located. In parallel, the Coonamessett River Trust (CRT) provided biological and chemical monitoring of the river system which continues today.
The restoration
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. In 2009, the Town 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. The active restoration was implemented in two phases: Phase 1, 2018; Phase 2, 2020.
