USGS Water-Year Summary 2020
02330450 CHATTAHOOCHEE RIVER AT HELEN, GA
LOCATION - Lat 34°42'03", long 83°43'44" referenced to North American Datum of 1983, White County, GA, Hydrologic Unit 03130001, on downstream side of bridge on GA 17 and 75 at Helen, and 1.1 miles downstream from Smith Creek.
DRAINAGE AREA - 44.7 mi².
PERIOD OF RECORD -
DISCHARGE: Miscellaneous low-flow measurements in water years 1953 and 1955. May 1981 to current year.
GAGE HEIGHT: October 1998 to current year.
GAGE - Satellite telemetry with a water-stage recorder and continuous water-temperature thermistor. Datum of gage is 1,404.04 feet above National Geodetic Vertical Datum (NGVD) of 1929.
COOPERATION - U.S. Army Corps of Engineers, Mobile District.
EXTREMES OUTSIDE PERIOD OF RECORD - Flood of August 23, 1967, reached a discharge of 11,000 cfs from contracted-opening computation at highway bridge 2.0 miles downstream at a drainage area of 48.2 mi².
EXTREMES FOR PERIOD OF RECORD - Maximum discharge recorded, 5,260 cfs, September 16, 2004; maximum gage height recorded, 6.75 feet, September 16, 2004; minimum daily discharge, 20 cfs, October 6, 1986, October 2, 15, 2007, and September 29, 30, 2016.
PERIOD OF RECORD - April 2003 to current year.
INSTRUMENTATION - Tipping-bucket raingage.
PERIOD OF DAILY RECORD -
WATER TEMPERATURE: July 2003 to current year.
INSTRUMENTATION - Satellite telemetry with a continuous water temperature thermistor.
EXTREMES FOR PERIOD OF DAILY RECORD -
WATER TEMPERATURE: Maximum recorded, 32.6°C, August 21, 2007; minimum recorded, -0.2°C, February 20, 2015.