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The formation of ice on rivers can cause discharge values to appear unusually high. Display of these erroneous discharge data may result in improper assessment of flow conditions and misuse of the data. For this reason, display of discharge values for streams significantly affected by ice may be disabled from view. Display of discharge data will resume when ice conditions are no longer present. Discharge values for streams minimally affected by ice will continue to be displayed. Flows for streams with these conditions appear to increase during the night and decrease to near-base-line conditions around midday. To estimate the correct discharge for these streams, use the flow rate that corresponds to the bottom of the discharge curve, rather than the peak that corresponds to the top of the curve. Note that this method of estimation is possible only when no surface runoff is occurring. Daily mean discharges for periods of both significant and minimal ice-effect will be estimated and published in the Annual Water-Data Report for the water year in which they occurred.



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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.
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.

This gage is monitored in cooperation with the Massachusetts Department of Conservation and Recreation, Division of Water Supply Protection, Office of Watershed Management, with funding from the Massachusetts Water Resources Authority .

Link to Department of Conservation and Recreation

Link to Massachusetts Water Resources Authority

Photo of Sudbury River looking Upstream. Link to the DCR.

Photo of Sudbury River looking Downstream. Link to the DCR.

Photo of Sudbury River looking Upstream

Photo of Sudbury River looking Downstream

Boating safety tips

This station managed by the Northborough MA Field Office.

Available Parameters Period of Record
1979-11-01  2021-09-20


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Summary of all available data for this site
Instantaneous-data availability statement

Discharge, cubic feet per second

Graph of DAILY Discharge, cubic feet per second

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