Nissitisset River near the confluence with the Nashua River

Our Rivers and Streams

Rivers and streams have been important to human existence from the beginning of time, first as a source of drinking water and food, and later becoming a means of transportation. The rivers and streams of our watershed are no different. The native people, and later colonists, were able to sustain their communities with the abundant supply of water, food, and shelter materials in our region. Rivers became pathways into interior lands, where new communities were settled, and the rivers were used for transporting goods to and from those towns. As the industrial age began, the power of the rivers was harnessed to provide energy to mills of all types. Today, the rivers flowing through our cities are a catalyst of economic revitalization, while the rivers flowing through our smaller communities provide numerous recreational opportunities. The rivers also serve as an indicator of the environmental health of the entire region’s ecosystem, because what we do on the land is reflected in the quality and quantity of our water.

So what rivers and streams flow through the Nashua River watershed? To answer that, first we need to know “What is a watershed?”  In the case of the Nashua River, the watershed includes all of the land draining water to the Nashua River, which meets the Merrimack River in Nashua, New Hampshire.

The Nashua River watershed can be divided into four major aggregate subwatersheds: North Nashua River, Wachusett Reservoir, Nashua River mainstem, and the Squannacook and Nissitissit Rivers watersheds.

North Nashua River (Massachusetts only)
The North Nashua begins at the confluence of the Whitman River and Flag Brook in west Fitchburg. Nine dams and flood control retaining walls dominate the North Nashua as it passes through the City of Fitchburg. The river receives discharges from both the East Fitchburg and Leominster Wastewater Treatment Plants, and stormwater runoff from the cities of Leominster and Fitchburg. The river flows through Leominster State Forest and agricultural fields before joining with the South Nashua River in Lancaster.

North Nashua River tributaries include: Fall Brook, Falulah/Baker Brook, Flag Brook, Monoosnoc Brook, Phillips Brook, Wekepeke Brook, and Whitman River.

Wachusett Reservoir Sub-basin (Massachusetts only)
Wachusett Reservoir and its tributaries in the southwestern portion of the Nashua River watershed are water supply sources for the Massachusetts Water Resources Authority (MWRA), the public water system in eastern Massachusetts that supplies drinking water to Boston and the metropolitan area. The reservoir is created by the Wachusett Dam in Clinton which was built in 1897. The Quinapoxet and Stillwater Rivers, both high quality water sources that flow into the reservoir, are popular cold water fisheries. The water exiting the dam forms the South Nashua River flowing north to meet the North Nashua River in Lancaster. The Clinton Wastewater Treatment Plant operated by the MWRA is located on the South Nashua River.

Wachusett Reservoir tributaries include: Ball Brook, Chaffins Brook, Connelly Brook, East Wachusett Brook, French Brook, Gates Brook, Houghton Brook, Justice Brook, Keyes Brook, Quinapoxet River, Rocky Brook, and Stillwater River.

Nashua River Mainstem Sub-basin (Massachusetts and New Hampshire)
The Nashua River mainstem forms the core of the Bolton Flats Wildlife Management Area and the Oxbow National Wildlife Refuge in Lancaster, Bolton, and Harvard where it winds north through marshy areas and former agricultural fields. Pepperell Dam in east Pepperell forms Pepperell Pond, an impoundment on the river popular for trophy large mouth bass and duck hunting. The river flows north through Hollis and Nashua, Hampshire where it joins the Merrimack River. The towns of Ayer and Pepperell have wastewater treatment plants discharging directly to the mainstem Nashua River. The Devens Wastewater Treatment Plant has a subsurface wastewater discharge.

Nashua River Mainstem tributaries include: Bowers Brook, Catacunemaug Brook, Flints Brook, James Brook, Mulpus Brook, Nonacoicus Brook, North Nashua River, South Nashua River, Still River, Unkety Brook, and Varnum Brook. 

Squannacook River in winter - Photo by Joan Wotkowicz

Squannacook and Nissitissit Rivers Sub-basin (Massachusetts and New Hampshire)
The Squannacook and Nissitissit Rivers both flow directly into the Nashua River Mainstem. The Squannacook River flows through Townsend and Shirley. Hollingsworth and Vose Company, a paper manufacturer, holds the only surface water discharge permit to the Squannacook River. The Nissitissit River flows south from Brookline, New Hampshire through Pepperell. Much of the land along both of these rivers is forested, and protected parcels include the Townsend State Forest, Squannacook Wildlife Management Area, Nissitissit River State Wildlife Management Area. Both rivers are popular cold-water fisheries.

Squannacook River tributaries include: Lock Brook, Mason Brook, Pearl Hill Brook, Trap Falls Brook, Walker Brook, Willard Brook, and Witches Brook.
Nissitissit River tributaries include: Beaver Brook, Gulf Brook, Lancey Brook, and Sucker Brook.

More on the water quality of our rivers and streams. 

More on recreation in our watershed.