The West Branch was historically a tidal river, bordered by salt marshes as it flowed south through Columbia and Addison to join the main stem of the Pleasant River.
The West Branch Pleasant River is a well-studied, coastal brackish marsh system, which for most of its history was the fourth largest contiguous area of tidal marsh in the state and the largest in Washington County. Today, the West Branch is part of the Pleasant Bay Beginning with Habitat Focus Area, which also includes the Narraguagus River, Beaver Meadow, Mill River, Cole Creek, Curtis Creek, Harrington River and the Pleasant River. This area was chosen by Inland Fisheries and Wildlife because of its relatively pristine brackish wetlands and mudflats that support tidal and inland waterfowl, rare plant communities, and rare animal species.
Over this history, the West Branch and its marshes have seen many phases of agricultural use and wildlife habitat evolution. These natural areas were originally utilized by the Wabanaki, and later by European settlers starting in the late 1700s. In the last ~250 years, the formerly tidal river and marsh floodplain has been significantly altered. However, considering the long history of these impacts, the marsh retains the primary character of a healthy salt marsh and is in good condition compared to others in the region. Today, a set of hinged tide gates, undersized upstream culverts, and significant beaver activity are the main concerns for the future wellbeing of the West Branch and the communities that surround it.
Like many areas along the Maine coast, the Pleasant River estuary and the communities around it are facing increasing pressures to adapt to rising sea levels and prepare for increasingly severe coastal storms. Along with the altered floodplain, sea level rise and increased intensity of storms has resulted in regular overtopping of local roads, flooding of surrounding property, and habitat that is unsuitable for a host of plants and animals.
The local effort to examine the costs and benefits of restoring tidal flow to the West Branch marsh began with the formation of the West Branch Study Committee in 2003. A second phase of effort saw the US Army Corps of Engineers study restoration alternatives. Following completion of these preliminary studies in 2019, renewed efforts to address infrastructure resiliency and restore the West Branch Marsh commenced in 2022.
