Data were downloaded from USGS web site:
http://waterdata.usgs.gov/ma/nwis/uv?dd_cd=01&dd_cd=03&dd_cd=14&format=g...

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LOCATION--Lat 42°45’10", long 70°56’46", Essex County, Hydrologic Unit 01090001, on left bank 1,400 ft downstream from dam, 0.5 mi south of Byfield, 0.7 mi upstream from Wheeler Brook, and 5.5 mi southwest of Newburyport.  
DRAINAGE AREA--21.3 mi2.
PERIOD OF RECORD--Discharge: October 1945 to current year. October 1945 monthly discharge only, published in WSP 1301.
Water-quality records: Water years 2003–04.
REVISED RECORDS--WDR MA-RI-84-1: Drainage area; WDR MA-RI-00-1: 1999.
GAGE--Data Collection Platform with satellite telemeter. Datum of gage is 23.46 ft above National Geodetic Vertical Datum of 1929 (levels by Massachusetts Department of Public Works).
COOPERATION BY--Massachusetts Department of Environmental Protection, Division of Watershed Management, Massachusetts Department of Conservation and Recreation

CALCULATIONS:
Published data from USGS is in ft3 sec-1. We have converted this to m3 sec-1 by multiplying the data by the following conversion factor: 1ft3 = 0.0283168 m3