Atlanta Flooding September 2009

In mid-September 2009, a persistent low-pressure area and deep moisture in the southeast lead to a prolonged, nine-day rain event in the Atlanta, Georgia metropolitan area. The most concentrated rainfall occurred September 20-22, with some areas receiving over 20 inches of rain in less than 48 hours. The heavy rainfall overnight on September 21 caused flash flooding in Carroll, Douglas, Paulding, Cobb and Gwinnett counties, leading to 9 fatalities. An additional fatality occurred in north Georgia (Chattooga County) during this event.

During the following two days, additional flash flooding and unprecedented river and creek flooding occurred, damaging and destroying homes, businesses and closing roads and bridges. Interstates 285, 20, 575, and 75/85 in and around Atlanta were all closed during different intervals due to flooding. Record crests were reported at thirty gages on creeks and rivers in north Georgia. In the town of Austell, an estimated 40% of homes were significantly damaged or destroyed. State and federal disaster assistance was available in 17 counties in the state.

This presentation will detail significant rainfall and flooding data as well as impacts to people and infrastructure in the area.