• View Watersheds by Region

    Map and downloadable files to locate watersheds by region.
  • Blackstone River Watershed

    The Blackstone River Watershed encompasses all or part of 29 communities in south central Massachusetts and Rhode Island.
  • Boston Harbor Watershed

    The Boston Harbor Watershed, encompassing approximately 293 square miles of land area, including all or part of 45 municipalities, as well as most of downtown Boston, is located in and around historic Boston Harbor.
  • Buzzards Bay Watershed

    Buzzards Bay is a moderately large estuary located in southeastern Massachusetts between the western-most portion of Cape Cod and Narragansett Bay in Rhode Island.
  • Cape Cod Watershed

    Extending 70 miles into the Atlantic Ocean, the Cape Cod Watershed is surrounded by the salt waters of Buzzards Bay, Cape Cod Bay, the Atlantic Ocean, and Nantucket Sound.
  • Charles River Watershed

    The Charles River Watershed has a drainage area of approximately 308 square miles and encompasses all or part of 35 municipalities.
  • Chicopee River Watershed

    The Chicopee River Watershed drains more than 720 square miles of central Massachusetts before joining the Connecticut River in the City of Chicopee.
  • Connecticut River Watershed

    The Connecticut River Watershed is the largest river ecosystem in New England, spanning over four New England states.
  • Deerfield River

    The Deerfield River, with its drainage area of approximately 665 square miles, is one of the coldest and cleanest rivers in Massachusetts.
  • Farmington River Watershed

    This picturesque mountain stream flows southerly for 18 miles through the Berkshires on its way to the mighty Connecticut River Valley.
  • French and Quinebaug Rivers Watershed

    The French & Quinebaug Watersheds and the Quinebaug-Shetucket River Valley form the Thames River Watershed.
  • Housatonic River Watershed

    The Housatonic River flows from north to south through a rolling valley between the Taconic Mountain Range of eastern New York State and the Berkshire Hills of western Massachusetts.
  • Hudson River Watershed

    The Hudson River Watershed of Massachusetts includes three distinct drainage basins covering a total of about 240 square miles.
  • Ipswich River Watershed

    Located in northeastern Massachusetts, the Ipswich River Watershed encompasses approximately 155 square miles of land and includes all or part of 21 communities.
  • Martha's Vineyard Island Watershed

    The Island of Martha's Vineyard, located off the southwest shore of Cape Cod, represents one of the two major island watersheds in Massachusetts.
  • Merrimack River Watershed

    The main branch of the greater Merrimack River is formed in central New Hampshire by the confluence of the Pemigewasset and Winnipesaukee Rivers.
  • Millers River Watershed

    The Millers River is located in north central Massachusetts, with approximately 20 percent of the watershed extending into the southern section of New Hampshire.
  • Nantucket Island Watershed

    The Island of Nantucket lies twenty-five miles south of Cape Cod and fifteen miles east of the Island of Martha's Vineyard, receives most of its fresh water from precipitation
  • Mount Hope / Narragansett Bay Watershed

    The Mount Hope Bay Shores and Narragansett Bay Watershed is located in southeastern Massachusetts and a small portion of eastern Rhode Island.
  • Nashua River Watershed

    The Nashua River Watershed has unusual characteristics; once a glacial lake that flowed southward through the Worcester area, its direction reversed forming the Nashua River Valley as a result of Pleistocene glaciation.
  • North Coastal Watershed

    The North Coastal Watershed has a total drainage area of approximately 168 square miles. It encompasses all or part of five river sub-basins, including the Danvers, Essex, Saugus, Pines, and Annisquam Rivers.
  • Parker River Watershed

    The Parker River Watershed is located in the northeast corner of the state, nestled between the Merrimack River Watershed to the north and the Ipswich River Watershed to the south.
  • Shawsheen River Watershed

    The Shawsheen River Watershed is located in northeastern Massachusetts with a total drainage area of approximately 78 square miles, including approximately 60 miles of named rivers and streams.
  • South Coastal Watersheds

    The South Coastal Watersheds consist of 14 coastal river watersheds with a total drainage area of approximately 240.7 square miles including the North and South Rivers, the Jones River, and the Gulf/Bound Brook.
  • SuAsCo Watershed

    The Sudbury-Assabet-Concord Watershed, located in the metro-west area of the state, encompasses a large network of tributaries that ultimately flow into the Merrimack River.
  • Taunton River Watershed

    The Taunton River Watershed is the second largest watershed in the state at 562 square miles. It contains 94 square miles of wetlands, including the largest in the state, Hockomock Swamp, as well as 221 lakes or ponds.
  • Ten Mile River

    The Ten Mile River Watershed is located in southeastern Massachusetts and a small portion of northeastern Rhode Island. It is the smallest of the 27 major watersheds in Massachusetts with a total drainage area of approximately 54 square miles.
  • Westfield River Watershed

    The Westfield River Watershed covers over 330,000 acres of land beginning along the eastern slopes of the Berkshires, flowing southward through both rural forested communities and urban centers, ending in the Connecticut River in Agawam.