USGS Water-Year Summary for Site 073802512

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	Available Parameters
	00010 Temperature, water(Max.,Min.,Mean)
	00065 Gage height(Max.,Min.,Mean)
	00095 Specific cond at 25C(Max.,Min.,Mean)
	00480 Salinity(Max.,Min.,Mean)

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Water year 2024: 2024-10-01 to 2025-09-30

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USGS Water-Year Summary 2024

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

REMARKS -

Stage affected by wind and tide. Satellite telemetry at station. 'e' denotes an estimated value.

Extremes to period of record may have been exceeded during period of missing record due to destruction by Hurricane Katrina, 2005; Hurricane Rita, 2005; Hurricane Ike, 2008; Hurricane Isaac, 2012; Hurricane Zeta 202; Hurricane Ida, 2021

Prior to Aug 29, 2021, site located approx. 0.5 miles south.

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.

REMARKS -

Turbidity data considered poor due to severe biofouling at the site location and extreme wind events causing significant turbulence.

Turbidity data that were previously reported in NTU were updated in October 2019 to reflect proper reporting units of FNU.

Extremes to period of record may have been exceeded during period of missing record due to destruction by Hurricane Ida, 2021.

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 FNU, on Apr. 6, 2017 (estimated); Minimum, 1.1 FNU, on Nov. 1, 2017. DISSOLVED OXYGEN: Maximum, 17.3 mg/L, on Feb. 2, 2017; Minimum, <0.3 mg/L, on Sep 18, 2019. PH: Maximum, 9.1 std. units, on Apr 29, 2021; Minimum 6.5 std. units, on Mar 20, 2019.