LOCATION--Lat 42^o22'08", long 71^o16'16", Middlesex County, Hydrologic Unit 01090001, 200 ft downstream of State Highway 20, 1,000 ft upstream from Stony Brook Reservoir, and 1.8 mi west of Waltham.
DRAINAGE AREA--22.0 mi².
PERIOD OF RECORD--October 1997 to September 1998; August 2002 to current year.
GAGE--Data Collection Platform, water-temperature, specific conductance, pH, and turbidity water-quality monitor, with telephone telemeter. Datum of gage is 89.20 ft above NAVD 1988, estimated from topographic map. Datum of gage previously reported as 90 ft above NGVD 1929, estimated from topographic map.
REMARKS--Flow affected by regulation of dam 2.6 mi upstream on Hobbs Brook at outflow of Cambridge Reservoir.
COOPERATION BY--Cambridge Water Department