PROVISIONAL DATA SUBJECT TO REVISION

LOCATION--Lat 42° 22’20", long 71° 14’03", Middlesex County, Hydrologic Unit 01090001, on right bank 800 ft downstream from Moody Street Bridge in Waltham and 0.3 mi upstream from Beaver Brook.
DRAINAGE AREA--227 mi², excludes 23.6 mi² drained by Stony Brook, from which flow is diverted for municipal supply of Cambridge.
PERIOD OF RECORD--Discharge: October 1903 to October 1909 (figures of average weekly discharge, equivalent to records of unadjusted discharge at present site), August 1931 to current year.
Water-quality records: Water years 1953, 1959, 1968–70.
REVISED RECORDS--WSP 781: 1933(M). WSP 851: drainage area. WSP 971: 1942.
GAGE--Water-stage recorder with satellite telemeter. Datum of gage is 20.02 ft above sea level. Prior to July 10, 1904, at dam 700 ft upstream and July 10, 1904, to Oct. 2, 1909, at dam 0.7 mi downstream at different datums; discharge computed from flow over dam and through wheels and gates of Boston Manufacturing Co. and Waltham Bleachery, respectively.
REMARKS-- Flow affected by diversion to Mother Brook (station 01104000), diversions to and from basin for municipal supplies, and at times by water released from Stony Brook Reservoir. Prior to 1960, some regulation by mills upstream. Low flow completely regulated by Boston Edison Co. power plant prior to 1954.
COOPERATION BY--Massachusetts Department of Conservation and Recreation, Division of Planning and Engineering