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- Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
- For water years 2014 onward, choose a water year and parameter and an on-demand Water-Year Summary report will be generated.
- For water years 2006 through 2013, choose a water year and an Annual Water Data Report will be provided.
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USGS Water-Year Summary 2024
01157000 ASHUELOT RIVER NEAR GILSUM, NH
LOCATION - Lat 43°02'21", long 72°16'14" referenced to North American Datum of 1927, Cheshire County, NH, Hydrologic Unit 01080201, on right bank, 50 ft downstream from White Brook, 60 ft upstream from stone-arch bridge just off Keene-Newport Road, 0.7 miles downstream from Gilsum and at mile 43.4.
DRAINAGE AREA - 71.1 mi².
REVISIONS HISTORY - WSP 661: Drainage area. WSP 781: 1934(M). WSP 1231: 1923-27(M), 1928, 1929-30(M), 1931, 1932(M). Gage heights for the period June 26 to July 12, 2018 were determined to be in error and removed on May 28, 2020.
SURFACE-WATER RECORDS
PERIOD OF RECORD - Discharge records: August 1922 to September 1980, July 2009 to current year.
Water-quality records: Water year 1955.
GAGE - Water-stage recorder. Datum of gage is 772.40 ft above North American Vertical Datum of 1988 (levels by U.S. Army Corps of Engineers). Prior to October 1, 1964, datum was 1.00 ft higher.
COOPERATION - New Hampshire Department of Environmental Services and USGS Groundwater and Streamflow Information Program.
REMARKS -
WATER YEARS 2014-15 and 2019-22: Records good except those for estimated discharges, which are poor.
WATER YEARS 2016-18, 2023: Records fair except those for estimated discharges, which are poor.
Some regulation by reservoir upstream. Prior to 1938, diurnal fluctuation caused by powerplant upstream.
EXTREMES OUTSIDE PERIOD OF RECORD - Maximum discharge since at least 1859, 10,200 ft³/s, Oct. 9, 2005, gage height, 17.98 ft, from floodmarks, on basis of slope-area measurement.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 7,410 ft³/s, July 11, 2023, gage height, 11.36 ft, present datum, from rating curve extended above 3,600 ft³/s; maximum gage height, 14.29 ft, Jan. 13, 2018 (from floodmarks, backwater from ice); maximum gage height unaffected by backwater, 13.80 ft, present datum, Mar. 19, 1936; minimum discharge, about 1 ft³/s, Oct. 6, 1922, July 10, 1923, and Nov. 14, 1952.
WATER-QUALITY RECORDS
PERIOD OF RECORD - October 1, 2015 to current year.
INSTRUMENTATION - Water-temperature recorder since October 1, 2015 provides continuous recordings.
REMARKS -
WATER YEARS 2016-22, 2024: Records good.
WATER YEARS 2023: Records good except July 25, 2023 to September 7, 2023 which are fair.
