USGS Water-Year Summary 2024
01127500 YANTIC RIVER AT YANTIC, CT
LOCATION - Lat 41°33'31", long 72°07'19" referenced to North American Datum of 1927, New London County, CT, Hydrologic Unit 01100003, on left bank at Yantic, 700 ft downstream from stone-arch highway bridge, 1 mi downstream from Susquetonscut Brook, and 4.8 mi upstream from mouth.
DRAINAGE AREA - 89.3 mi².
REVISIONS HISTORY - WSP 1051: 1931-36. WSP 1301: 1934 (M). WDR CT-78-1: 1970-77 (P). WDR CT-82-1: 1979-80 (P). WDR CT-83-1: Drainage area, 1979 (P), 1982 (P).
SURFACE-WATER RECORDS
PERIOD OF RECORD - Discharge: October 1930 to current year.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 93.53 ft above North American Vertical Datum of 1988 (94.46 ft above National Geodetic Vertical Datum of 1929). Satellite telemetry at station.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 13,500 ft³/s, Sep. 21, 1938, gage height, 14.66 ft, from computation of flow over two dams 2.4 mi. upstream and 3.0 mi. downstream, respectively. Maximum peak stage, 14.88 ft., June 6, 1982, the result of backwater due to reconstruction of the river bank. Minimum discharge, 2.2 ft³/s, Aug. 30, 1963 and Oct. 8, 2016.
WATER-QUALITY RECORDS
PERIOD OF RECORD - October 1954 to September 1958, 1963 to 1964, 1968 to 1980, October 2007 to current year. Daily suspended-sediment discharge: water years 1975-80.
PERIOD OF DAILY RECORD - Specific Conductance, pH, Water Temperature, Dissolved Oxygen, Turbidity, Chlorophyll RFU, February 2020 to May 2023.
INSTRUMENTATION -
--Multiparameter sonde, Feb. 2020 to May 2023.
--Independent turbidity probe, Feb. 2020 to May 2023.
EXTREMES FOR PERIOD OF DAILY RECORD -
--SPECIFIC CONDUCTANCE @25 °C: Maximum, 549
µS/cm Mar. 4, 2023; minimum, 40.2
µS/cm Jan. 26, 2023.
--pH: Maximum, 9.74 standard units Jul. 17, 2022; minimum, 6.4 standard units Jul. 09, 2021.
--WATER TEMPERATURE: Maximum, 30.5˚C Aug. 09, 2022; minimum, -0.1°C Dec. 17, 2020; and many days in winters 2020, 2021, and 2022.
--DISSOLVED OXYGEN: Maximum, 15.7 mg/L Jan. 11 and Jan. 16, 2022; minimum, 4.5 mg/L Aug. 07, 2022.
--TURBIDITY: Maximum, 969 FNU Dec. 25, 2020; minimum, 0 FNU Oct. 11 2020 and many days from 2020 to 2023.
--CHLOROPHYLL: Maximum, 99.83 RFU Jul. 22, 2022; minimum, 0.0 RFU Mar. 19, 2022 and many days in 2022 & 2023.