Impacts of the Atlanta Floods, September 2009


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Presentation on the impacts of the Atlanta floods of September 2009. Presented at the American Meteorological Society Annual Meeting, January 19, 2010, Atlanta, GA.

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Impacts of the Atlanta Floods, September 2009

  1. 1. ATLANTA FLOODS: SEPTEMBER 20-23, 2009 Melissa Tuttle Carr - Freelance Meteorologist, CNN American Meteorological Society Annual Meeting 2010
  2. 2. Flooding Set-Up <ul><li>Wetter than normal August into September </li></ul><ul><li>Persistent low pressure area feeding Gulf of Mexico moisture into the southeast, with daily rain starting in the Atlanta metro area on September 15 </li></ul><ul><li>Some areas had already received 6+ inches of rain prior to the heavy rainfall overnight September 20 </li></ul>
  3. 3. Flooding Set-Up <ul><ul><li>Source: National Weather Service Forecast Office, Peachtree City, GA </li></ul></ul>
  4. 4. Flooding Set-Up <ul><li>Heavy rains, </li></ul><ul><li>Sept. 20-21 </li></ul><ul><li>Sept. 20, 2009 </li></ul><ul><li>2329Z </li></ul><ul><ul><li>Image: National Weather Service Forecast Office, Peachtree City, GA </li></ul></ul>
  5. 5. Flooding Set-Up <ul><li>Heavy rains, </li></ul><ul><li>Sept. 20-21 </li></ul><ul><li>Sept. 21, 2009 </li></ul><ul><li>0143Z </li></ul><ul><ul><li>Image: National Weather Service Forecast Office, Peachtree City, GA </li></ul></ul>
  6. 6. Flooding Set-Up <ul><li>Heavy rains, </li></ul><ul><li>Sept. 20-21 </li></ul><ul><ul><li>Sept. 21 1300Z </li></ul></ul><ul><li>(9 AM EDT) </li></ul><ul><li>18-hour accumulation </li></ul><ul><li>Max: 15.04 inches </li></ul><ul><ul><li>Some locations </li></ul></ul><ul><li>received 20 inches </li></ul><ul><li>of rain in 24 hours </li></ul><ul><ul><li>Image: National Weather Service Forecast Office, Peachtree City, GA </li></ul></ul>
  7. 7. Flash Floods, Sept. 20-21 <ul><li>Fatalities </li></ul><ul><ul><li>Nine flash flood fatalities in the Atlanta metro area </li></ul></ul><ul><ul><ul><li>Eight in vehicles </li></ul></ul></ul><ul><ul><ul><li>One in a mobile home </li></ul></ul></ul><ul><ul><li>One additional flood fatality in NW Georgia (rescue attempt) and another near Chattanooga, TN ($5 bet) </li></ul></ul><ul><li>Roads </li></ul><ul><ul><li>Numerous roads and </li></ul></ul><ul><ul><li>bridges washed out </li></ul></ul>Winston, GA, Monday, Sept. 21 (AP Photo/Atlanta Journal Constitution, John Spink)
  8. 8. Flooding, Sept. 21-23 <ul><ul><li>Cumulative heavy rainfall lead to urban flooding and historic river flooding </li></ul></ul><ul><ul><li>26 new record high crests were established at locations on 21 different creeks/rivers </li></ul></ul><ul><ul><li>20 USGS streamgauges were overtopped , one by 12 feet </li></ul></ul><ul><ul><li>Sources: National Weather Service Forecast Office, Peachtree City, GA; </li></ul></ul><ul><ul><li>US Geological Service (2009, November 9). ‘Atlanta Floods Extremely Rare’. Science Daily </li></ul></ul>
  9. 9. Flooding, Sept. 21-23 <ul><ul><li>“ At some sites, the annual chance of a flood of this magnitude was so significantly less than 1 in 500 that, given the relatively short length of streamgauging records (well less than 100 years), the U.S. Geological Survey cannot accurately characterize the probability due to its extreme rarity. ” </li></ul></ul><ul><ul><li>- Robert Holmes, USGS National Flood Program Coordinator </li></ul></ul>
  10. 10. Flooding, Sept. 21-23 <ul><ul><li>AUSG1 – Sweetwater Creek, 3SE Austell, GA </li></ul></ul><ul><ul><li>8:55 PM EDT Sept. 22 </li></ul></ul><ul><ul><li>Last observed value was 18.21 feet when gauge failed at 3:30 PM, Sept. 21 </li></ul></ul><ul><ul><li>Crest recorded at 30.17 feet, later corrected to 30.80 feet using high water marks </li></ul></ul>
  11. 11. Flooding, Sept. 21-23 <ul><ul><li>Gauge Height Hydrograph, Sept. 15-26 </li></ul></ul>Flood Stage: 10 feet Normal Stage: 1-2 feet Previous Record Crest: 21.81 feet Forecast Crest: 21.21 feet Actual Crest: 30.80 feet
  12. 12. Flooding, Sept. 21-23 Normal days at Sweetwater Creek State Park (1-3 feet)
  13. 13. Flooding, Sept. 21-23 Sept. 23, 2009, day after crest Approx. 21.8 feet in this photo (previous record crest)
  14. 14. Flooding, Sept. 21-23
  15. 15. Flooding, Sept. 21-23 <ul><li>Impacts </li></ul><ul><ul><li>$500 million in damages </li></ul></ul><ul><ul><li>17 counties under federal disaster declaration </li></ul></ul><ul><ul><li>27,000 families, individuals and businesses registered with FEMA (as of 11/22/09) </li></ul></ul><ul><ul><li>40% of homes in town of Austell significantly damaged or destroyed </li></ul></ul><ul><ul><li>Many school districts closed for days </li></ul></ul><ul><ul><li>Hundreds of people rescued from homes via boat </li></ul></ul><ul><ul><li>Approx. 300 roads closed/destroyed </li></ul></ul><ul><ul><li>I-75/85, I-20, I-285, I-575 all had closures </li></ul></ul>
  16. 16. Flooding, Sept. 21-23 <ul><li>Road Closures </li></ul><ul><ul><li>Downtown Connector (I-75/I-85) at evening rush hour, Sept. 21 – Urban flooding/ heavy rain </li></ul></ul><ul><ul><li>Photo: AJC </li></ul></ul>
  17. 17. Flooding, Sept. 21-23 <ul><li>Road Closures </li></ul><ul><ul><li>I-20 near Lee Road west of Atlanta, Sept. 23 </li></ul></ul><ul><li>Photo: Phil Skinner, AJC </li></ul>
  18. 18. Flooding, Sept. 21-23 <ul><li>Road Closures </li></ul><ul><ul><li>Veterans Memorial Highway in Austell as Sweetwater Creek continued to rise, Sept. 21 </li></ul></ul>
  19. 19. River Flooding, Sept. 21-23 <ul><li>Businesses Damaged </li></ul>
  20. 20. River Flooding, Sept. 21-23
  21. 21. River Flooding, Sept. 21-23 AP Photo
  22. 22. River Flooding, Sept. 21-23 AP Photo
  23. 23. River Flooding, Sept. 21-23
  24. 24. River Flooding, Sept. 21-23 <ul><li>Schools Damaged </li></ul>Clarkdale Elementary School, Austell Photo courtesy Phil Skinner, AJC
  25. 25. River Flooding, Sept. 21-23 Photos taken Mid-October
  26. 26. River Flooding, Sept. 21-23
  27. 27. River Flooding, Sept. 21-23
  28. 28. River Flooding, Sept. 21-23
  29. 29. River Flooding, Sept. 21-23
  30. 30. River Flooding, Sept. 21-23 AP Photo
  31. 31. River Flooding, Sept. 21-23 September 23 Mid-October: Water line still evident
  32. 32. River Flooding, Sept. 21-23 <ul><li>Water Quality Issues </li></ul><ul><ul><li>Rivers contained high levels of E. Coli, raw sewage (broken sewage lines, water treatment plant inundation) </li></ul></ul>
  33. 33. Woes continue… <ul><li>Many flooded homes still not fixed and are unoccupied </li></ul><ul><li>Many homeowners walking away from damaged homes </li></ul><ul><li>Cobb County and town of Austell to ask government to buy out 250 flooded homes (AJC, January 14, 2010) </li></ul>
  34. 34. Acknowledgements <ul><li>National Weather Service: Service Assessment Team for Southeast Flooding </li></ul><ul><ul><li>John Jannuzzi, Brent MacAloney, Keith Stellman, Rick Shanklin, Nezette Rydell, Jim Noel, Chris Vaccaro, NWS; Don McKinnon, Jones County, MS Emergency Manager; myself </li></ul></ul><ul><ul><li>Report forthcoming </li></ul></ul><ul><li>National Weather Service Forecast Office, Peachtree City </li></ul><ul><ul><li>Lans Rothfusz, Kent Frantz, John Feldt, and many others </li></ul></ul><ul><li>Weather and Society-Integrated Studies (WAS*IS) colleagues! </li></ul>
  35. 35. Contact <ul><li>Melissa Tuttle Carr - [email_address] </li></ul>