North and South Rivers Watershed Association (NSRWA), the Town of Marshfield, our staff, volunteers, and partners have been long awaiting the removal of the dam at Veterans Memorial Park in Marshfield. For the past 369 years, river herring have traveled from the Atlantic Ocean through the South River, up to this spot, where they were hindered from traveling any further due the dam. A fish ladder was eventually installed, but never functioned properly and most fish were still unable to pass. This dam removal project has been in the works since 2012, and the results have been immediate.
What once was an obsolete mill dam and poorly functioning fish ladder obstructed fish passage, is now a newly-constructed series of pools and riffles that vastly improve their access to spawning areas upstream. This project would not have been possible without support from the Town of Marshfield, Marshfield residents and Veterans, the National Fish and Wildlife Foundation, and NSRWA. We are also grateful for our citizen scientist herring counters who have helped us gather data at this site since 2008.
This is one of the only dam removal projects where the Massachusetts Division of Marine Fisheries (DMF) has approved the construction of a temporary bypass channel to pass fish during the migratory season. Throughout construction, contractor Flynn Enterprises and DMF worked closely to ensure sufficient flow for fish passage, requiring multiple tweaks to the bypass channel throughout the process. As a result, river herring have not only traveled upriver through this site, but experts have also observed spawning behavior upstream. This is significant because any juveniles that survive will come back to this system to spawn in 3 years.
Construction resumed in July, when the spring spawning run ended. The river began to run again, as the temporary bypass channel was closed and flow was returned to the main channel on July 29th, 2025. The project is set to be completed by November 2025, excluding minimal landscaping additions that will continue throughout the spring. Site restoration is the next step, including a lagoon, fountain, and water wheel, along with park improvements.
An unexpected twist to the construction included rescuing trapped eels and removing invasive species. After the bypass channel was disconnected, the NSRWA team came to pull up purple loosestrife, an invasive plant that threatens native wetland species. In addition, many American Eels became stuck in the draining temporary bypass stream, requiring human intervention to move them back to water. The team successfully moved around 20 very slippery eels and encouraged others to move towards the running water.
Stay tuned for more updates as the park comes back to life!