With June temperatures routinely hitting the 90s and little rain so far this summer, drought conditions have worsened across Georgia.
Conditions in the western half of south and middle Georgia have deteriorated the most. A few weeks ago, these regions were classified as abnormally dry. They are now in severe drought.
Severe drought now exists west and north of a line crossing Lowndes, Cook, Tift, Turner, Crisp, Dooly, Houston, Bibb, Jones, Baldwin, Hancock, Glascock, Warren, McDuffie and Richmond counties. It includes Albany, Atlanta, Augusta, Columbus, Macon and Rome. Severe drought conditions occur about once in 20 years.
Much of north Georgia is in extreme drought. This includes an area north and east of a line crossing Lincoln, Wilkes, Taliaferro, Greene, Morgan, Walton, Gwinnett, Forsyth, Dawson, Gilmer and Fannin counties. The cities are Athens, Blairsville, Clayton, Cumming, Gainesville and Madison. Extreme drought conditions occur about once in 50 years.
Moderate drought conditions exists in Echols, Lanier, Berrien, Irwin, Ben Hill, Wilcox, Pulaski, Dodge, Bleckley, Twiggs, Wilkinson, Laurens, Washington, Johnson, Jefferson, Burke, Jenkins, Screven and Effingham counties. Moderate drought conditions occur about once in 10 years.
Clinch, Atkinson, Coffee, Telfair, Wheeler, Treutlen, Emanuel, Candler, Bullock, Evans, Liberty, Bryan and Chatham counties are in mild drought, which occurs about once in seven years.
Abnormally dry counties are Camden, Charlton, Ware, Bacon, Jeff Davis, Montgomery, Toombs, Tattnall, Long and McIntosh.
Currently, the only counties not in drought are Glynn, Brantley, Pierce, Appling and Wayne. However, a hot, dry July could cause drought to develop rapidly.
The biggest concern over the next several weeks will be stream flows and soil moisture.
Almost half of the U.S. Geological Survey stream gauges across Georgia are at record low flows as of June 25. This analysis includes only gauges with a minimum of 30 years of records. It doesn’t include gauges on the Chattahoochee River below the Buford Dam or gauges on the Savannah River.
Streams at daily record low flows include the Chattahoochee River near Cornelia, the Etowah River at Canton, the Notteley River near Blairsville, the Chattoga River near Clayton, the Broad River near Bell, the Flint River near Carsonville, Oakfield, Albany and Newton, the Oconee River at Athens, Milledgeville and Dublin, the Ocmulgee River near Jackson and Lumber City, the Ohoopee River near Reidsville, the Withlacoochee River near Quitman and Ichawaynochaway Creek near Milford.
Several streams are at or below their 7Q10 flow value, which is the 7-day flow that has only a 10 percent chance of occurring in any given year. When it does happen, it typically occurs in September or October, when stream flows are normally at their lowest for the year.
Seeing streams at or below the 7Q10 in late June indicates the severity of the current conditions.
Streams currently below their 7Q10 are the Broad River near Bell, the Little River near Washington, the Ocmulgee River near Jackson, the Oconee River at Dublin, the Flint River at Carsonville and Ichawaynochaway Creek at Milford.
Streams slightly above their 7Q10 are the Middle Oconee at Athens and the Chattooga River near Clayton.
Soil moisture levels are extremely low north of a line from Seminole County to Screven County.
North of a line from Chattahoochee County to Richmond County the levels are at or below the 10th percentile. At this percentile, we would expect more moisture in the soils 90 out of 100 years in late June.
North of a line from Columbia County to Hall County to Fannin County, levels are at or below the 5th percentile. At the 5th percentile, we would expect more moisture in the soils 95 out of 100 years in late June.
Farm ponds, especially ones not fed by springs, are showing the lack of rain. Many ponds didn’t receive adequate recharge during the winter and entered the summer already low.
Through October, Georgia’s best chance for widespread drought relief will be tropical disturbances. The tropics usually don’t become active until late summer.
More drought information can be found at www.georgiadrought.org. Automated weather data across Georgia is at www.georgiaweather.net. Daily rainfall from CoCoRaHS is available at www.cocorahs.org. USGS data is at ga.water.usgs.gov. Water conservation information is available at www.conservewatergeorgia.net.
(David Emory Stooksbury is associate professor of Biological and Agricultural Engineering at University of Georgia's College of Agricultural and Environmental Sciences.)
Georgia map shows only five counties not experiencing drought conditions as of June 25.Download Image