USGS Water-Year Summary 2020
073802512 Hackberry Bay NW of Grand Isle, LA
LOCATION - Lat 29°23'54", long 90°02'28" referenced to North American Datum of 1927, Jefferson Parish, LA, Hydrologic Unit 08090301, on a two-tier wellhead platform approximately 10.7 miles northwest of Grand Isle Coast Guard Station.
DRAINAGE AREA - Indeterminate.
SURFACE-WATER RECORDS
PERIOD OF RECORD - October 1994 to current year.
GAGE - Water-stage recorder. Datum of gage is 0.48 below NAVD 88 GEOID03. Prior to Oct. 12, 2005 datum of gage was 0.32 ft below NAVD 88 GEOID96. Prior to Oct. 1, 1998, datum of gage was 0.24 ft above NAVD 88 GEOID93. Prior to Oct. 1, 1996, datum of gage was 16.13 ft below NAVD 88.
COOPERATION - Louisiana Department of Wildlife and Fisheries and Louisiana Coastal Protection and Restoration Authority
EXTREMES FOR PERIOD OF RECORD - Maximum recorded gage height, 7.51 ft, Sept. 1, 2008 and e7.51 ft, Aug. 29, 2012; minimum recorded gage height, e-3.25 ft, Aug. 28, 2012.
WATER-QUALITY RECORDS
PERIOD OF RECORD - WATER TEMPERATURE: Oct 1994 to current year.
SPECIFIC CONDUCTANCE: Oct 1994 to current year.
SALINITY: Oct 1994 to current year.
TURBIDITY: July 2016 to current year.
pH: July 2016 to current year.
CHLOROPHYLL-A: July 2016 to current year.
DISSOLVED OXYGEN: July 2016 to current year.
PERIOD OF DAILY RECORD - SPECIFIC CONDUCTANCE: October 1994 to current year.
SALINITY: October 2002 to current year.
WATER TEMPERATURE: October 1994 to current year.
PH: June 2016 to current year.
DISSOLVED OXYGEN: June 2016 to current year.
TURBIDITY: June 2016 to current year.
CHLOROPHYLL-A: June 2016 to current year.
INSTRUMENTATION - Water-quality monitor recording specific conductance, water temperature, pH, chlorophyll A, turbidity, and dissolved oxygen.
EXTREMES FOR PERIOD OF RECORD -
SPECIFIC CONDUCTANCE: Maximum, 55,900 microsiemens/cm, on January 4, 2019; minimum, 334 microsiemens/cm, on Jan. 10, 2010.
SALINITY: Maximum, 29.8 ppt, on Aug. 4, 2012; Minimum, 0.2 ppt, on many days.
WATER TEMPERATURE: Maximum, 35.2°C, on Aug. 9, 1995; minimum 1.7°C, on Jan. 10, 2010.
TURBITITY: Maximum, 516 NTU, on Apr. 6, 2016; Minimum, 1.1 NTU, on Nov. 1, 2017.
DISSOLVED OXYGEN: Maximum, 17.3 mg/L, on Feb. 2, 2017; Minimum, 0 mg/L, on Sep 18, 2019.
PH: Maximum, 9.0 std. units, on Feb.1 , 2017; Minimum 6.5 std. units, on Mar 20, 2019.