Construction crews have begun a significant environmental restoration project in Marshfield's Veterans Memorial Park, marking a major milestone in the years-long effort to restore one of Massachusetts' ecologically significant waterways.
The project, focused on removing an obsolete dam and fish ladder, represents the first major step in transforming the South River - a critical ecosystem that originates in Duxbury's red maple swamps and winds its way to Massachusetts Bay through Marshfield.
The Veterans Memorial Park dam, situated 8.8 miles from Massachusetts Bay, has long been the first impediment to fish migration along the river. The existing pool and weir fish ladder has allowed only limited passage for the river's diverse marine life, including alewife, blueback herring, American eel, and sea lamprey. American shad, which spawn at the head of tide, and isolated populations of wild eastern brook trout in the river's tributaries, will also benefit from the restoration.
The dam removal project earned Priority Project status from the Massachusetts Division of Ecological Restoration (DER) in 2016, highlighting its significance to regional conservation efforts. The new design will replace the dam with a nature-like fishway featuring a series of shallow, step-like stone riffles, allowing improved fish passage while maintaining the park's beloved features.
In a careful balance of environmental restoration and historical preservation, the project includes installation of a sophisticated groundwater cistern system to maintain water levels in the park's heart-shaped lagoon and operate its historic water wheel, particularly during low-flow periods. The renovation also includes upgrades to honor local veterans, featuring new ADA-accessible pathways overlooking the restored river section.
The initiative is part of a larger effort to improve the South River's ecosystem, which faces challenges from multiple human-made alterations along its course. The river system currently includes two other major dams upstream: the privately-owned Chandler Pond dam at 9.5 miles from the ocean, and the Temple Street dam in Duxbury. Several former cranberry bog sites also impact the river's flow and ecosystem health.
The project represents a collaboration between environmental organizations and community stakeholders, including the North and South Rivers Watershed Association, MassBays, the Town of Marshfield, Massachusetts Division of Ecological Restoration, Marshfield Veterans, and the National Fish and Wildlife Foundation.
Following the dam removal, restoration of the river channel will begin, with ongoing monitoring of the river's herring run and management of upstream vegetation to reduce flooding and support fish passage.