Nashua River - Watershed

Watershed

From its impoundment at the Wachusett Reservoir in Clinton, Massachusetts, the South Branch of the Nashua River flows north and joins the North Branch of the Nashua River in Lancaster, Massachusetts. The North Branch of the Nashua River flows southeast from Fitchburg and Leominster, Massachusetts to Lancaster. The Nashua river flows northward from Lancaster, meandering its way through the north-central Massachusetts towns of Harvard, Groton, Dunstable, and Pepperell, before eventually emptying into the Merrimack River at Nashua, New Hampshire. The Nashua River Watershed has a total drainage area of approximately 538 square miles (1393 km²), with 454 square miles (1176 km²) of the watershed occurring in Massachusetts and 74 square miles (192 km²) in New Hampshire. The Nashua River flows for approximately 56 miles (90 km), with approximately 46 of those miles (74 km) flowing through Massachusetts. The Squannacook, Nissitissit, Stillwater, Quinapoxet, North Nashua, and South Nashua Rivers feed it. The watershed encompasses all or part of thirty-one communities, seven in southern New Hampshire and twenty-four in central Massachusetts. The watershed’s largest water body is the Wachusett Reservoir, which provides drinking water to two-thirds of the Commonwealth's population.