Sudbury River
The Sudbury River is a tributary of the Concord River in Middlesex County, Massachusetts, in the United States.
Originating in the Cedar Swamp in Westborough, Massachusetts, near the boundary with Hopkinton, the Sudbury River meanders generally northeast, through Fairhaven Bay, and to its confluence with the Assabet River at Egg Rock in Concord, Massachusetts, to form the Concord River. It has a drainage area. A 1775 map identifies the river by this name as passing through the town of Sudbury, itself established 1639.
On April 9, 1999, nearly of the river were "recognized for their outstanding ecology, history, scenery, recreation values, and place in American literature," by being designated as a part of the National Wild and Scenic Rivers System. The segment of the Sudbury River beginning at the Danforth Street Bridge in the city of Framingham, downstream to the Route 2 bridge in Concord, is designated as a Scenic River, and the segment from the Route 2 bridge downstream to its confluence with the Assabet River at Egg Rock is designated as a Recreational River, along with adjoining stretches of the Assabet and Concord rivers.
Mercury contamination was discovered in the 1970s from the Nyanza plant in Ashland. The EPA subsequently listed the town as a toxic site and led a cleanup effort to repair the damage. It is still recommended that fish caught downriver not be eaten.
Name
An 1834 book on the history of Concord, Lemuel Shattuck, stated that in Concord the river upstream of the Assabet River was considered a continuation of the Concord River, but also some instances the south branch of the Concord and the Assabet the north branch. In Sudbury town records the river was referred to as the Great River early on, later the Sudbury River. West of Framingham the Sudbury was called the Hopkinton River. Not until 1856 maps was it the Sudbury River from Westborough to Concord.Geography
The Sudbury River starts at Cedar Swamp Pond in a swampy area in Westborough and flows northeast, starting at an elevation of and descending through the towns of Westborough, Hopkinton, Southborough, Ashland, Framingham, Wayland, Sudbury, Lincoln and finally Concord, where it merges with the Assabet River at Egg Rock to form the beginning of the Concord River, at an elevation of. As of 2017 there are five historic dams on the Sudbury River: two Framingham Reservoir dams, Fenwick Street Dam and Saxonville Dam in Framingham, and Myrtle Street Dam, in Ashland. The river is crossed by 34 road bridges, five railroad bridges and two footbridges. Its watershed covers.Starting in November 1979 the U.S. Geological Survey installed and maintains a gauge for river depth and flow rate on the Sudbury River, downstream of the Danforth Street Bridge, Saxonville, Framingham. The upstream watershed is, 65% of the total Sudbury River watershed. The average flow rate for 37 years of complete data is 201 cubic feet per second. Flow rate changes with seasons – summer months average 80 cfs while spring months average 375cfs. Highest recorded flow was 2,570 cfs on March 31, 2010. Water depth at the gauge on that date was 13.95 feet. Any time depth exceeds 13.0 feet the river is considered to be in major flood status. Last major flood before 2010 was April 8, 1987, 13.47 feet.