Moderate drought conditions have returned to parts of Georgia, generally south of a line from Toccoa to Atlanta to Franklin. North of this line, the state ranges from abnormally dry to mild drought. Conditions are best north and west of Atlanta.
The driest part of the state is east of a Toccoa-to-Cairo line. Most places in this region have had less than 12 inches of rain this year. Normal rainfall would be 18 to 26 inches since Jan. 1.
Rainfall deficits for Jan. 1 through May 25 for major cities include: Athens, 10.84 inches; Atlanta, 8.94; Augusta, 6.31; Columbus, 7.44; Macon, 5.39; and Savannah, 5.50.
Just as important is the moisture loss from the soils through evaporation and transpiration (plant water use).
Because of the early arrival of temperatures in the upper 80s to lower 90s, moisture loss from the soils has accelerated.
In a normal year, soil moisture increases between Jan. 1 and the end of May. The increase would range from more than 4 inches in drier places to more than 12 inches in the wetter mountain areas.
For many places in Georgia, soil moisture has dropped since Jan. 1. Alma has had a soil moisture loss of 5.74 inches, Cairo 3.88 inches, Camilla 2.30, Dearing 2.58, Griffin 1.35, Jonesboro 2.01, Plains 2.23, Savannah 3.25, Statesboro 5.00, Valdosta 4.12 and Watkinsville 1.19.
Across north Georgia, soil moisture has increased since Jan. 1. However, the amount of increase is well below normal. Sites reporting soil moisture increases include Alpharetta, 2.65 inches; Atlanta (Clark-Atlanta University), 0.02; Blairsville, 5.06; Dunwoody, 1.33; LaFayette, 3.43; and Rome, 8.80.
Soil moisture data is from the 50-plus weather stations in the University of Georgia Automated Environmental Monitoring Network.
As we entered late May, soil moisture loss through evaporation and transpiration was normally greater than rainfall. So even with normal rainfall, the soils will keep drying out through early October.
U.S. Geological Survey stream gauges are showing extremely low flows across the entire state, except the northwest corner. Several stations have stream flows at 25 percent to 50 percent of normal for late May. Record to near-record low flows for late May are found in southeast Georgia.
Based on USGS data, groundwater didn't get normal recharges last winter. With record to near-record dryness in March through mid-May and increased irrigation, groundwater levels are beginning to drop. Many monitoring wells in southwest Georgia are near levels last seen in late 2002, when Georgia was recovering from the 1998-2002 drought.
The normal recharge season for groundwater is over. Levels are expected to keep dropping through summer into fall.
Because of abundant rainfall from September 2002 through June 2003 and prudent management by the Army Corps of Engineers, the state's major reservoirs are in good shape.
However, smaller lakes and farm ponds are beginning to show drought impacts. If the low inflow into the major reservoirs continues, water levels will soon begin to drop noticeably.
The major drought impact so far has been in agriculture.
The Georgia Agricultural Statistics Service reports that some farmers are re-evaluating their options. Hay production is down. Some growers have had to do supplemental feeding because of the poor quality of pastures. Pasture conditions are especially in poor shape across middle Georgia.
Irrigation is being used to supplement low soil moisture.
Drought conditions are expected to continue through summer. Tropical activity is usually the only hope of widespread drought relief during the summer. Scattered afternoon and evening thunderstorms can bring temporary local relief, but usually won't end a regional drought.
Because of the dry conditions, extra water conservation measures are encouraged. Suggestions are available from your county UGA Extension Service office or local water utility.
David Stooksbury is the state climatologist and a professor of engineering and atmospheric sciences in the University of Georgia College of Agricultural and Environmental Sciences.