Nashua watershed map
The Nashua River Watershed has unusual characteristics. The river was once a glacial lake that flowed southward through the Worcester area, but as a result of the Pleistocene glaciation, its direction reversed and the Nashua River Valley was created.

From its impoundment at the Wachusett Reservoir, the mainstem of the river flows northward, meandering its way through north-central Massachusetts before eventually emptying into the Merrimack River in southern New Hampshire.

The Nashua River Watershed has a total drainage area of approximately 538 square miles, with 454 square miles of the watershed occurring in Massachusetts and 74 square miles in New Hampshire. The Nashua River flows for approximately 56 miles, with approximately 46 of those miles flowing through Massachusetts, and is fed by the Squannacook, Nissitissit, Stillwater, Quinapoxet, North Nashua, and South Nashua Rivers.

The watershed encompasses all or part of 31 diverse communities, 7 in southern New Hampshire and 24 in central Massachusetts. Residents value the beauty of their local area and the conservation of open space, which protects water quality, wildlife habitats, farms, and forests and provides increased recreational opportunities. The watershed is also home to the Wachusett Reservoir, which provides drinking water to two-thirds of the Commonwealth's population.

Watershed Priorities

  • Address existing long-term water quality problems
  • Evaluate point and non-point source pollutant loadings through Total Maximum Daily Loads and National Pollutant Discharge Elimination System permits
  • Complete hydrologic assessments and implement recommendations and follow-up actions
  • Restore and protect water quality from non-point source pollution and implement sub-watershed assessments and goals
  • Manage growth and encourage careful land use with well-planned development to minimize the loss of open space

Watershed Successes


Fun on the river
On December 6, 2002, former Secretary Robert Durand designated both the Squannassit and Petapawag ACECs. The total land area exceeds 60,000 acres and increases the ACEC program area by nearly one-fourth. The two new ACECs contain an extraordinarily diverse concentration of highly significant environmental resources. An important aspect of the ACEC designation is the creation of a framework to provide for long-term stewardship of these critical resources.

The designation of this ACEC was the result of a tremendous amount of work, beginning with the tremendous efforts of the Squannassit/Petapawag Initiative. Formal outreach began in September of 2001 and continued throughout 2002. The committee, coordinated by the Nashua River Watershed Association, submitted for review two nominations for consideration for an ACEC designation. The Squannassit and Petapawag nominations are based on extensive research encompassing several years of active involvement by local and state environmental specialists. These areas include portions of eleven towns in the northern Nashua Watershed and some of the Merrimack Watershed as well. 

Last year, the Nashua River Watershed was selected as one of four river systems for the national demonstration Source Water Stewardship Project funded through the Environmental Protection Agency. This work identifies and prioritizes those lands that are most appropriate for source water protection activities.

This spring, the Squannacook/Nissitissit sub-watershed communities will benefit from a Source Water Stewardship Exchange. With the guidance and involvement of the host committee, a team of four to five professionals from around the country, familiar with similar watershed management issues, will be invited to participate in a one week 'stewardship exchange' in the watershed. During the exchange, the host committee will work closely with the stewardship team to analyze the data and develop potential management alternatives for protecting source waters.

The Nashua Watershed Five-Year Action Plan is now complete and ready for distribution. By outlining specific strategies to mitigate priority watershed problems it will promote integrated watershed natural resource protection or improvement. The environmental priorities identified in this comprehensive plan may be used to focus local and regional regulatory decision making and to target state grant programs and other resources such as educational and technical assistance programs. The plan is organized on a sub-basin basis. There are 22 distinct sub-basins in the larger Nashua River Watershed. Major components in the plan's creation include stakeholder participation, community involvement, and public review.

Watershed Publications

Watershed Links

Nashua River Watershed Association
Montachusett Regional Planning Commission

This information is provided by the Executive Office of Energy and Environmental Affairs, Office of Water Policy