USGS Water-Year Summary 2019
02335450 CHATTAHOOCHEE RIVER ABOVE ROSWELL, GA
LOCATION - Lat 33°59'09", long 84°18'58" referenced to North American Datum of 1927, Fulton County, GA, Hydrologic Unit 03130001, on right bank at Eves Road, 3.3 miles upstream from Big Creek, and 2.2 miles upstream from GA 400, 3.6 miles southeast of Roswell, and at mile 320.6.
DRAINAGE AREA - 1,220 mi².
PERIOD OF RECORD -
DISCHARGE: October 1941 to May 1960 (published as 02335500, Chattahoochee River "near Roswell"), July 1976 to current year.
GAGE HEIGHT: October 1998 to current year.
GAGE - Satellite telemetry with a water-stage recorder. Datum of gage is 858.6 feet above North American Vertical Datum (NAVD) of 1988 (leveling by Global Positioning System equipment). Prior to July 7, 1976, at site 1.8 miles downstream at datum 8.51 feet lower.
COOPERATION - Georgia Power Corporation.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge recorded, 56,000 cfs, January 8, 1946; maximum gage height recorded, 23.40 feet, January 8, 1946; minimum daily discharge, 315 cfs, August 11, 1957.
EXTREMES FOR PERIOD PRIOR TO REGULATION - Maximum discharge recorded, 56,000 cfs, January 8, 1946, from rating curve extended above 30,000 cfs on basis of peak flows over Morgan Falls Dam; maximum gage-height recorded, 23.40 feet, January 8, 1946.
PERIOD OF DAILY RECORD -
WATER TEMPERATURE: January 2004 to December 2006 and September 2011 to current year.
INSTRUMENTATION - Satellite telemetry with a continuous water temperature thermistor.
EXTREMES FOR PERIOD OF DAILY RECORD -
WATER TEMPERATURE: Maximum recorded, 24.2°C, July 9, 2017; minimum recorded, 3.3°C, February 19, 2015.