USGS Water-Year Summary 2024

01160350 ASHUELOT RIVER AT WEST SWANZEY, NH

LOCATION - Lat 42°52'17", long 72°19'43" referenced to North American Datum of 1927, Cheshire County, NH, Hydrologic Unit 01080201, on left bank, 100 ft downstream of California/Main Street bridge in West Swanzey, 4.6 mi downstream from South Branch Ashuelot River, 5.1 mi southwest of City Hall in Keene, and 18.2 mi upstream from mouth.

DRAINAGE AREA - 316 mi².

REVISIONS HISTORY - Revisions: The maximum discharges for water years 2014-2020 were revised on Dec. 20, 2022 based on changes to the stage-discharge rating.

SURFACE-WATER RECORDS

PERIOD OF RECORD - Discharge records: April 1994 to current year. Peak streamflow: Water years 1994 to current year. Miscellaneous discharge measurements only: Water year 1990.

GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 441.95 ft above North American Vertical Datum of 1988. Prior to Aug. 13, 2010, at datum 11.20 ft higher. From August 13, 2010 to September 9, 2013, at site 400 ft downstream.

COOPERATION - City of Keene, NH.

REMARKS - WATER YEAR 2014-23: Records good except those for estimated discharges, which are poor. Flow regulated by Surry Mountain Lake 20 mi upstream since 1942, and by Otter Brook Lake 16 mi upstream on Otter Brook since 1958. Some regulation by small hydro plants upstream.

EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 6,210 ft³/s, Oct 9, 2005, gage height, 5.62 ft (datum then in use); maximum gage height, 6.30 ft, Mar 7, 1999 (ice jam; datum then in use).

WATER-QUALITY RECORDS

PERIOD OF RECORD - Water-quality discrete samples: Water years 1994 to 1999.