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USGS Water-Year Summary 2024
02203960 SNAPFINGER CREEK AT THOMPSON MILL ROAD NEAR LITHONIA, GA
LOCATION - Lat 33°41'48", long 84°11'55" referenced to North American Datum of 1983, Dekalb County, GA, Hydrologic Unit 03070103,
DRAINAGE AREA - 32.6 mi². revised.
REVISIONS HISTORY - WDR GA-2013: Drainage Area.
SURFACE-WATER RECORDS
PERIOD OF RECORD -
DISCHARGE: February 2012 to current year.
GAGE-HEIGHT: February 2012 to current year.
DISCHARGE: February 2012 to current year.
GAGE-HEIGHT: February 2012 to current year.
GAGE - Satellite telemetry with a water-stage recorder. Datum of gage is 749.26 feet above the North American Vertical Datum (NAVD) of 1988 (leveling by Global Positioning System equipment).
COOPERATION - DeKalb County Department of Watershed Protection.
REMARKS - Gage-height records are generally good. Discharge records are generally fair 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, 3,080 cfs, October 11, 2020; maximum gage-height recorded, 17.54 feet, October 11, 2020; minimum daily discharge, 1.9 cfs, September 27, 2012.
CLIMATOLOGICAL RECORDS
PERIOD OF RECORD - February 2012 to current year.
INSTRUMENTATION - Tipping-bucket rain gage.
WATER-QUALITY RECORDS
PERIOD OF RECORD - November 2012 to current year.
PERIOD OF DAILY RECORD -
SPECIFIC CONDUCTANCE: November 2012 to current year.
PH: November 2012 to current year.
WATER TEMPERATURE: November 2012 to current year.
DISSOLVED OXYGEN: November 2012 to current year.
TURBIDITY: November 2012 to current year.
SPECIFIC CONDUCTANCE: November 2012 to current year.
PH: November 2012 to current year.
WATER TEMPERATURE: November 2012 to current year.
DISSOLVED OXYGEN: November 2012 to current year.
TURBIDITY: November 2012 to current year.
INSTRUMENTATION - Satellite telemetry, a continuous water-quality monitor, and an automated refrigerated sampler.
REMARKS -
For period 10/01/2014-09/30/2015: Specific conductance record rated good. pH record rated good. Water temperature record rated good. Dissolved Oxygen record rated good. Turbidity record rated poor.
For period 10/01/2015-10/21/2015: Specific conductance record rated good. pH record rated good. Water temperature record rated excellent. Dissolved Oxygen record rated good. Turbidity record rated fair.
For period 10/22/2015-09/30/2016: Specific conductance record rated good. pH record rated good. Water temperature record rated excellent. Dissolved Oxygen record rated good. Turbidity record rated fair.
For period 10/01/2016-09/30/2017: Specific conductance record rated good. pH record rated good. Water temperature record rated good. Dissolved Oxygen record rated good. Turbidity record rated fair.
For period 10/01/2017-09/30/2018: Specific conductance record rated good. pH record rated good. Water temperature record rated good. Dissolved Oxygen record rated good. Turbidity record rated 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). Hydrologic event 9 indicates a routine sample while J designates a storm event sample. Laboratory chemical analyses are by RTI Laboratory, Livonia, MI. Laboratory sediment analyses are by the U.S. Geological Survey, KY Sediment Laboratory. Field determinations of discharge, specific conductance, pH, water temperature, turbidity, dissolved oxygen, microbiology, and barometric pressure are by the U.S. Geological Survey.
For period 10/01/2014-09/30/2015: Specific conductance record rated good. pH record rated good. Water temperature record rated good. Dissolved Oxygen record rated good. Turbidity record rated poor.
For period 10/01/2015-10/21/2015: Specific conductance record rated good. pH record rated good. Water temperature record rated excellent. Dissolved Oxygen record rated good. Turbidity record rated fair.
For period 10/22/2015-09/30/2016: Specific conductance record rated good. pH record rated good. Water temperature record rated excellent. Dissolved Oxygen record rated good. Turbidity record rated fair.
For period 10/01/2016-09/30/2017: Specific conductance record rated good. pH record rated good. Water temperature record rated good. Dissolved Oxygen record rated good. Turbidity record rated fair.
For period 10/01/2017-09/30/2018: Specific conductance record rated good. pH record rated good. Water temperature record rated good. Dissolved Oxygen record rated good. Turbidity record rated 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). Hydrologic event 9 indicates a routine sample while J designates a storm event sample. Laboratory chemical analyses are by RTI Laboratory, Livonia, MI. Laboratory sediment analyses are by the U.S. Geological Survey, KY Sediment Laboratory. Field determinations of discharge, specific conductance, pH, water temperature, turbidity, dissolved oxygen, microbiology, and barometric pressure are by the U.S. Geological Survey.
EXTREMES FOR PERIOD OF RECORD -
SPECIFIC CONDUCTANCE: Maximum recorded, 502 microsiemens, January 23, 2018; minimum recorded, 15 microsiemens, July 21, 2013.
pH: Maximum recorded, 8.5 units, July 16, 17, 2014; minimum recorded, 5.8 units, September 2, 2016.
WATER TEMPERATURE: Maximum recorded, 29.5°C, June 17, 2022; minimum recorded, -0.1°C, January 30, 2014.
DISSOLVED OXYGEN: Maximum recorded, 13.8 mg/L, January 8, 2014, January 5, 18, 2018; minimum recorded, 3.8 mg/L, May 5, 2013.
TURBIDITY: Maximum recorded, 1050 FNU, September 7, 2014; minimum recorded, 0.7 FNU, September 5, 2018.
SPECIFIC CONDUCTANCE: Maximum recorded, 502 microsiemens, January 23, 2018; minimum recorded, 15 microsiemens, July 21, 2013.
pH: Maximum recorded, 8.5 units, July 16, 17, 2014; minimum recorded, 5.8 units, September 2, 2016.
WATER TEMPERATURE: Maximum recorded, 29.5°C, June 17, 2022; minimum recorded, -0.1°C, January 30, 2014.
DISSOLVED OXYGEN: Maximum recorded, 13.8 mg/L, January 8, 2014, January 5, 18, 2018; minimum recorded, 3.8 mg/L, May 5, 2013.
TURBIDITY: Maximum recorded, 1050 FNU, September 7, 2014; minimum recorded, 0.7 FNU, September 5, 2018.
