USGS Water-Year Summary 2023
01194750 CONNECTICUT RIVER AT ESSEX, CT
LOCATION - Lat 41°21'05.34", long 72°23'03.72" referenced to North American Datum of 1983, Middlesex County, CT, Hydrologic Unit 01080205, on the right bank of the Connecticut River on the north end of the fixed dock of The Connecticut River Museum at Essex Village, CT. Approximately 2.6 miles north of the I-95 bridge between North Cove and Middle Cove, just south of the Essex Island Marina and just north of the Essex Town Dock. Secondary gage (for water quality) is on the north end of the docks of The Essex Island Marina.
DRAINAGE AREA - 11,200 mi².
SURFACE-WATER RECORDS
PERIOD OF RECORD - Feb. 2010 to current year.
GAGE - Water-stage recorder. Datum of gage is National Geodetic Vertical Datum of 1929. Satellite telemetry at station.
EXTREMES FOR PERIOD OF RECORD - Maximum river elevation, 7.98 ft., Oct. 29, 2012; minimum tidal elevation, -2.92 ft., Jan. 05, 2018.
WATER-QUALITY RECORDS
PERIOD OF DAILY RECORD -
WATER TEMPERATURE(MAIN): Feb.21, 2010 to Jun.05, 2019. SPECIFIC CONDUCTANCE(MAIN):Oct. 02, 2011 to Jun. 05, 2017. SALINITY(MAIN):Feb.21, 2010 to Jun. 05, 2019. DISSOLVED OXYGEN(MAIN):Feb.28, 2010 to Jun.05, 2019. PH(MAIN):Feb.21, 2010 to Jun.05, 2019. TURBIDITY(MAIN):Feb.25, 2010 to Jun. 05, 2019. WATER TEMPERATURE(TOP):Feb.25, 2010 to Nov.01, 2017. SPECIFIC CONDUCTANCE(TOP):Feb.21, 2010 to Sep.30, 2020. SALINITY(TOP):Feb.21, 2010 to Jun.05, 2019 to current year. WATER TEMPERATURE(BOTTOM):Feb.25, 2010 to Nov.01, 2017. SPECIFIC CONDUCTANCE(BOTTOM):Feb.21, 2010 to Sep.30, 2020. SALINITY(BOTTOM):2010 to Jun.05, 2019 to current year.
INSTRUMENTATION - Water-quality monitors Feb. 2010 to current year. Two monitors at station are on an upstream dock, one is near the top of the river (called "TOP"), the other is near the bottom of the river (called "BOTTOM").
EXTREMES FOR PERIOD OF RECORD - WATER TEMPERATURE (MAIN): Maximum, 30.4 °C, Jul. 12, 2010; minimum, -0.1 °C, on several days.
SPECIFIC CONDUCTANCE (MAIN): Maximum, 42,200 microsiemens, Sep. 18, 2012; minimum, 54 microsiemens, Mar. 31, 2010.
SALINITY (MAIN): Maximum, 27 psu, Sep. 18, 2012; minimum, 0 psu, on many days.
TURBIDITY (MAIN): Maximum, 170 FNU, Oct. 28, 2012; minimum, 0.1 FNU, Aug. 20, Sep. 1, 21, 2010.
WATER TEMPERATURE (TOP): Maximum, 30.3°C, Jul. 29, 2020; minimum, -0.2 °C, on many days.
SPECIFIC CONDUCTANCE (TOP): Maximum, 42,825 microsiemens, Oct. 18, 2016; minimum, 65 microsiemens, Aug.3, 2014.
SALINITY (TOP): Maximum, 27.5 psu, Oct. 18, 2016; minimum, 0 psu, on many days.
TURBIDITY (TOP): Maximum, 30.7 FNU, Apr. 16, 2020; minimum, 1.1 FNU, May 30,2020.
PH(TOP):Maximum, 9.0 pH units, Aug. 10, 2019; minimum, 6.9 pH units , Apr. 19, 2020.
DISSOLVED OXYGEN(TOP): Maximum, 14.9 mg/L, Jan. 21, 2020; minimum, 4.9 mg/L, Aug. 01, 2020, Aug. 24, 2020.
FDOM(TOP):Maximum, 51.9QSE, Nov. 08, 2019; minimum,8.0 QSE Oct. 17, 2019.
CHLOROPHYLL(TOP):Maximum 34.2 RFU, Aug. 29, 2019: minimum, 0.32 RFU, Dec. 08, 2019.
WATER TEMPERATURE (BOTTOM): Maximum, 30.2°C, Jul. 30, 2020; minimum, -0.2 °C, Feb. 20, 2011.
SPECIFIC CONDUCTANCE (BOTTOM): Maximum, 44,200 microsiemens, Sep. 02, 2015; minimum, 56 microsiemens, May. 22, 2011.
SALINITY (BOTTOM): Maximum, 28.5 psu, Sep. 02, 2015; minimum, 0 psu, on many days.
DISSOLVED OXYGEN(BOTTOM): Maximum, 14.7 mg/L, Dec. 23, 2019 and Jan. 21, 2020; minimum, 3.8 mg/L, Jul. 16, 2020 and Sep. 11,2020.