LOCATION--Lat 42°19’31", long 71°23’53", Middlesex County, Hydrologic Unit 01070005, on left bank at downstream side of new Danforth Street Bridge, at Saxonville, 600 ft east of Elm Street, 700 ft downstream from confluence with Lake Cochituate Outlet, and 0.7 mi downstream from Saxonville Dam.
DRAINAGE AREA--106 mi².
PERIOD OF RECORD--Discharge: November 1979 to current year.
Water-quality records: Water years 1994–95.
GAGE--Data Collection Platform with satellite telemeter. Datum of gage is 109.78 ft above NAVD 1988, from Massachusetts Department of Public Works benchmark (Disk 1306). Prior to May 13, 2020, datum reported as 110.55 ft above NGVD 1929, from Massachusetts Department of Public Works benchmark (Disk 1306).
REMARKS--Flow regulated by reservoirs upstream and affected by diversions and spill. Flow may be diverted as needed for emergency use in MWRA metropolitan Boston service area.

Photo of Sudbury River looking Upstream

Photo of Sudbury River looking Downstream

Boating safety tips