Our Watershed

The Sudbury, Assabet, and Concord rivers watershed, also known as the SuAsCo, covers 399 square miles in 36 municipalities in Massachusetts. It contains 83.7 miles of rivers, innumerable streams and ponds, 36 miles of hiking trails, and a long history of human use. The headwaters of the Assabet and Sudbury rivers are in Westborough from where they flow north until they meet at Egg Rock in Concord, Massachusetts, and become the Concord River. The Concord flows north to the Merrimack River in Lowell, which enters the Atlantic Ocean at Plum Island in Newburyport, Massachusetts. This watershed is also known as the Concord watershed or Concord Basin.

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Our watershed includes, in whole or in part, Acton, Ashland, Bedford, Berlin, Billerica, Bolton, Boxborough, Boylston, Carlisle, Chelmsford, Clinton, Concord, Framingham, Grafton, Harvard, Holliston, Hopkinton, Hudson, Lincoln, Littleton, Lowell, Marlborough, Maynard, Natick, Northborough, Sherborn, Shrewsbury, Southborough, Stow, Sudbury, Tewksbury, Upton, Wayland, Westborough, Westford, and Weston.