USGS Water-Year Summary for Site 01119500

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	Available Parameters
	00060 Discharge(Mean)
	00065 Gage height(Mean)

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

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USGS Water-Year Summary 2023

01119500 WILLIMANTIC RIVER NEAR COVENTRY, CT

LOCATION - Lat 41°45'02", long 72°15'58" referenced to North American Datum of 1927, Tolland County, CT, Hydrologic Unit 01100002, on left bank 700 ft upstream from bridge on State Rt. 31, 1 mi downstream from Mill Brook, 2.4 mi southeast of South Coventry, 2.8 mi upstream from Hop River and 6.3 mi upstream from mouth.

DRAINAGE AREA - 121 mi².

REVISIONS HISTORY - WSP 781: 1934 (m). WSP 851: 1935-36. WSP 1201: 1932 (M, m), 1933-34, 1937, 1939-42. WDR 79-1: 1978 (m). WDR CT-83-1: Drainage area.

SURFACE-WATER RECORDS

PERIOD OF RECORD - Discharge: October 1931 to current year. Water-quality records: Water years 1956-57, 1963-64, 1975-80.

GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 238.04 ft above North American Vertical Datum of 1988, prior to 12/29/2021 datum of gage was 239.05 ft above National Geodetic Vertical Datum of 1929. Satellite telemetry at station.

REMARKS -

Effects of flood-control dams in the Middle River Basin (Ellithorpe Reservoir Dam No. 5, Ellis Reservoir Dam No. 2, Whitney Reservoir Dam No. 1, Shenipsit Reservoir Dam No. 6, Pomeroy Reservoir Dam No. 3, and Bradway Reservoir Dam No. 4) on peak flows are minor. Usable storage at the gaging station from flood control is about 31 acre-feet per square mile. The natural flow of stream can be altered by regulation from Staffordville Reservoir and the flood-control dams.

Water year 2022-2023: The record is considered good except for periods of estimated discharge, which are fair.

Water year 2021: The record is considered as fair from Oct. 1, 2020 - Apr. 13, 2021, otherwise record considered as good.

Water year 2018-2020: Record considered poor.

Water years 2017: Record considered fair from Oct. 1, 2016 to Feb. 27, 2017 and considered as poor from Feb. 28, 2012 to Sep. 30, 2017.

Water year 2016: Record considered good except for period between Jun. 27, 2016 to Sep. 30, 2016 which are fair and period between Dec. 29, 2015 to Feb. 3, 2016 and periods of estimated daily discharge which are poor

Water year 2013-2015: Record considered good except those for periods of estimated daily discharge, which are poor.

EXTREMES FOR PERIOD OF RECORD - The maximum peak flow of 24,200 ft³/s was obtained from the rating curve extended above 3,600 ft³/s on basis of computation of flow over dam at gage height 12.2 ft., and from contracted opening measurement of peak flow. The maximum peak stage of 18.66 ft. was from flood marks.