The U.S. Geological Survey says Atlanta area flooding last week involved magnitudes so great the odds of it happening were less than 1 in 500 in many areas.
“The USGS can reliably say just how bad these floods were. They were epic!” said Brian McCallum, assistant director of the USGS Water Science Center in Georgia.
On Tuesday, USGS crews said they measured the greatest flow ever recorded (28,000 cubic feet per second) on Sweetwater Creek near Austell, Ga.
In Georgia, the USGS maintains a network of more than 300 stream gages that provide data in real time. Data from those gages are used by local, state and federal officials for numerous purposes, including public safety and flood forecasting by the National Weather Service.
A map of the gages and graphs of last week’s discharge are available at http://ga.water.usgs.gov/flooding-sept09.html.