USGS Water-Year Summary 2024

01085000 CONTOOCOOK RIVER NEAR HENNIKER, NH

LOCATION - Lat 43°09'07", long 71°51'28" referenced to North American Datum of 1927, Merrimack County, NH, Hydrologic Unit 01070003, on right bank, 1.6 mi downstream from Sand Brook, 2.6 mi southwest of Main Street, Bridge Street (NH 114), and Maple Street intersection in Henniker, and 3.2 mi northeast of Bridge Street (NH 149) and West Main Street (US 202) intersection in Hillsborough.

DRAINAGE AREA - 368 mi².

REVISIONS HISTORY - WSP 1701: 1944 (M).

SURFACE-WATER RECORDS

PERIOD OF RECORD - Discharge records: October 1939 to September 1977 and October 2015 to present. Partial-record station: October 1977 to September 2015. Peak Streamflow: Water years 1938, 1940 to 1977, 1980, and 1989 to current year. Miscellaneous Discharge measurements: Water years 1978 to 1982, 1988 to current year.

GAGE - Water-stage recorder and crest-stage gage. The datum of gage is 469.70 ft above North American Vertical Datum of 1988. Prior to Dec. 18, 1939, nonrecording gage at same site and datum.

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

REMARKS - 10/01/2015-09/30/2023: Records good except those for estimated discharges, which are poor. Flow regulated by powerplants and by Nubanusit Lake, Edward MacDowell Reservoir, since March 1950, Highland Lake, Lake Franklin Pierce, and other reservoirs upstream.

EXTREMES OUTSIDE PERIOD OF RECORD - Maximum discharge since at least 1768, 22,200 ft³/s, Sept. 21, 1938, gage height, 21.3 ft, from floodmarks, from rating curve extended above 7,500 ft³/s on basis of computation of flow over dams at gage heights 12.72 ft and 21.3 ft.

EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 13,100 ft³/s, Apr. 17, 2007, gage height, 14.54 ft.

WATER-QUALITY RECORDS

PERIOD OF RECORD - Water-Quality Field/Lab samples: Water years 1953 to 1959, 1964, 1967 to 1970, 1974 to 1977, 1989, 1991 to 1999.