USGS Water-Year Summary for Site 01085500

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	Available Parameters
	00060 Discharge(Mean)

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Water year 2023: 2022-10-01 to 2023-09-30

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USGS Water-Year Summary 2023

01085500 CONTOOCOOK RIVER BELOW HOPKINTON DAM, AT WEST HOPKINTON, NH

LOCATION - Lat 43°11'34", long 71°44'52" referenced to North American Datum of 1927, Merrimack County, NH, Hydrologic Unit 01070003, on right bank, 400 ft downstream from covered bridge at West Hopkinton, 0.2 mi downstream from Hopkinton Dam, 2.6 mi southwest of State Highways 103 and 127 intersection in Contoocook, 3.6 mi west of State Highway 103 and US 202 intersection in Hopkinton, and 6.0 mi upstream from Warner River.

DRAINAGE AREA - 427 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD - Discharge records: August 1903 to April 1907 (monthly discharges only, no winter records, published as "at West Hopkinton"), August 1963 to September 1989, October 2001 to March 2013, October 2014 to present. Partial-record station: October 1989 to September 30, 2001, April 1, 2013 to September 30, 2014. Peak streamflow: Water years 1964 to current year. Miscellaneous discharge measurements: Water years 1963 to present. Water-quality discrete samples: Water years 1965, 1967 to 1970, 1975 to 1999.

GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 355.15 ft above North American Vertical Datum of 1988. August 1903 to April 1907, nonrecording gage at site 400 ft upstream at different datum.

COOPERATION - U.S. Army Corps of Engineers, New England District.

REMARKS -

WATER YEARS 2015-22: Records good except for estimated discharges, which are poor.

Flow regulated by power plants and by Nubanusit Lake, Edward MacDowell Reservoir since 1950, Highland Lake, Lake Franklin Pierce, Hopkinton Lake since 1962 (Reservoirs in Merrimack River basin), and other reservoirs upstream. Diversion from Hopkinton Lake to Everett Lake on the Piscataquog River during periods of high flow in March 1968, April 1969, March 1977, March 1979, May-June 1984, April 1987, March-April 2003, April 2005, October 2005, May 2006, April 2007, and March-April 2010.

EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 7,530 ft³/s, April 8, 1987, gage height, 10.89 ft. Period of peak streamflow record is water year 1964 to current year.