The Nemasket River Study

Content submitted by: Emily Vogler, Helen Zincavage, Bill Napolitano

The Nemasket River is a small but important river in Southeast Massachusetts. It flows North 11.5 miles from its headwaters at the Assawompset Pond, through Middleborough, to its confluence with the Wild & Scenic Taunton River. The Taunton River Stewardship Council (TRSC) is currently funding and participating in a community-based project, through our TRSC Grants Program, to address longstanding issues in the upper Nemasket River Watershed.

five boats paddle down a calm river with green vegetation on each riverbank
Members of the survey committee survey the Nemasket River.

Emily Vogler

The main issues being looked at on the Nemasket River are:

  • Fish Passage - The Assawompset Pond Complex is the largest natural lake complex in Massachusetts and provides key spawning grounds for migratory fish. As a result, the Nemasket River supports one of the largest coastal river herring populations in Southeast New England, but increasing sedimentation, proliferation of aquatic vegetation/invasives, and downstream dams have led to migratory problems for juvenile herring over the past several years.
  • Flow - The flow of the Nemasket River has been altered by the construction of dams. The slowing of the river between the dams and the periodic release of sand that has built up behind the Assawompset Pond dam has led to an increase in sedimentation along the Nemasket River. The sedimentation has narrowed the river channel and the shallow bottom has in turn led to the growth of invasive aquatic weeds that have further narrowed the river channel. The shallow channel and aquatic plants make it difficult for migratory fish to navigate the river. In addition, there are inadequate stream flows in summer months which limit the recreational opportunities on the river.
  • Flooding - Due to the altered hydrology and development near the Nemasket River, there are issues with flooding along the river. In 2010 there was a 100-year flood that severely impacted the surrounding communities of Lakeville, Rochester, Freetown, and Middleborough. A storm event like that will happen again and it is important to address the flow issues in the river to reduce the future impact of flooding on residences and infrastructure.

Given these underlying issues, there is an opportunity to bring people together to discuss possible ways to help strengthen the resilience of the local community to future floods, improve connectivity along the river and improve recreational opportunities in the region.

Our goal for this project is to bring together the general public, state and local organizations, agencies and non-profits to take a systematic and holistic approach to looking at all of the issues along the Nemasket River and explore alternatives that may provide multiple benefits. The following values underlie our work:

  • Environmental management decisions benefit from a meaningful and robust input from the surrounding community.
  • Both scientific facts and individual and community values should be factored into the decision-making process.
  • Our goal is to help support and facilitate the discussion but not to advocate for any specific solution, but rather to come out of this process with a preferred alternative that can be put forth as a recommendation to the decision -making authorities.

Last updated: January 21, 2022