USGS Water-Year Summary for Site 02335880

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	Available Parameters
	00010 Temperature, water(Max.,Min.,Mean)
	00045 Precipitation(Sum)
	00045 Precipitation(Sum) [Operational]
	00060 Discharge(Mean)
	00065 Gage height(Mean)
	00095 Specific cond at 25C(Max.,Min.,Mean)
	63680 Turbidity, Form Neph(Med.,Max.,Min.)

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

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USGS Water-Year Summary 2023

02335880 CHATTAHOOCHEE RIVER AT POWERS FERRY & I-285 NEAR ATLANTA, GA

LOCATION - Lat 33°54'07.1", long 84°26'34.9" referenced to North American Datum of 1983, Fulton County, GA, Hydrologic Unit 03130001,

SURFACE-WATER RECORDS

GAGE - Satellite telemetry with water-stage recorder. Datum of gage is 777.24 feet above North American Vertical Datum (NAVD) of 1988.

REMARKS -
Gage-height records are generally good. Discharge records are generally good except for estimated discharges, which are poor. Additional details on the accuracy of the records can be obtained by contacting the USGS South Atlantic Water Science Center at gs-w-ga_nwisweb_data_inquiries@usgs.gov.

EXTREMES FOR PERIOD OF RECORD - Maximum discharge recorded, 22,700 cfs, October 11, 2020; maximum gage height recorded, 11.61 feet, October 11, 2020; minimum daily discharge, 1000 cfs, July 27, 2020.

WATER-QUALITY RECORDS

REMARKS -
For period 03/30/2016-09/30/2016: Continuous water temperature records and specific conductance records are rated good. Turbidity records are fair.
For period 10/01/2016-11/06/2016: Continuous water temperature records and specific conductance records are rated good. Turbidity records are fair.

Data for parameter code 63680 (turbidity) were collected using a probe with the following specifications: turbidity, water, monochrome near infra-red LED light, 780-900 nm, detection angle 90 +/-2.5 degrees, FNU (Formazin Nephelometric Units). Prior to October 1, 2004, turbidity data were published using parameter code 00076: turbidity, water, unfiltered, NTU (Nephelometric Turbidity Units).

Discrete sample turbidity measurements are taken in the lab using a Hach 2100 and are reported in Nephelometric Turbidity Ratio Units, (NTRU). Calibration is performed on the meter using Hach supplied and approved standards. USGS Georgia District policy has stated that turbidity will have a lower reporting threshold of 2 NTRU and an upper limit of 1,100 NTRU. The precision and accuracy associated with turbidity has required the overall record to be rated fair.

EXTREMES FOR PERIOD OF RECORD -

SPECIFIC CONDUCTANCE: Maximum recorded, 134 microsiemens, October 19, 2017; minimum recorded, 32 microsiemens, on August 29, 2023. WATER TEMPERATURE: Maximum recorded, 28.2°C, July 10, 2017; minimum recorded, 2.5°C, January 18, 2018. TURBIDITY: Maximum recorded, 547 FNU, June 15, 2017; minimum recorded, 1.3 FNU, March 16, 2023.