Parts of Southeast Saw Record-Low Streamflow in August

Streams in North Carolina and Georgia were flowing at record-low levels last month, thanks to a combination of high temperatures and drought, according to news from the U.S. Geological Survey (U.S.G.S.).

In North Carolina, the Tar River at Tarboro had its lowest-ever average streamflow in 110 years of record-keeping, the U.S.G.S. reported. In Georgia, rivers seeing record-low flows included the Oconee River at Dublin (lowest in 110 years), the Conasauga River at Tilton (lowest in 69 years), the Coosawattee River near Ellijay (lowest in 67 years) and the Coosa River near Rome (lowest in 56 years).

In Georgia, said U.S.G.S. hydrologist Mark Landers, "We began the summer in extremely dry conditions with the lowest May streamflows ever observed for many streams. June and July rainfalls did not replenish the rainfall deficit, and August has been extremely dry. At a few sites, streamflows are even lower than during the droughts of the 1950s, 1980s and 1998-2002."

As of the end of July, nearly half of the contiguous U.S. was in some stage of drought, according to the most recent data available from the National Climatic Data Center. Drought was affecting 80 percent of the Southeast, with the northern half of Alabama experiencing the most severe lack of rainfall.

The combination of low flow rates and high heat poses a threat to fish and other stream wildlife, according to the U.S.G.S. In North Carolina, average water temperatures at 16 monitoring stations were about 3 degrees Fahrenheit higher than normal for August. The Neuse River at New Bern saw water temperatures 3.4 degrees Fahrenheit higher than normal, while the Hyce River in Person County was 4 degrees Fahrenheit warmer than typical

Georgia, meanwhile, saw groundwater levels decline by varying amounts across the state. In the area around Atlanta, one well tapped into the region's crystalline rock aquifer set a 27-year record low.

"Drought conditions across Georgia have worsened dramatically since the beginning of August," said David Stooksbury, Georgia state climatologist. "Widespread triple-digit high temperatures and very little rain have caused soil moisture levels to plummet, stream flows to approach record lows and groundwater and lake levels to drop sharply."

The data gathered during the current drought might help scientists develop a better understanding of how future changes in rainfall could affect the region, said Landers.

"Because severe droughts of this nature may occur only once in 100 years, the U.S.G.S. hopes to use the new information about extreme low flows measurements to develop a large-scale study," he said. "A state-wide comprehensive project could provide crucial information for future understanding of limited water resources."

U.S. Geological Survey, "Lowest Streamflows in More Than 110 Years for Some North Carolina Rivers as Drought Worsens." "Lowest Streamflows in More Than 60 Years for Some Georgia Rivers as Drought Worsens." URL: (http://www.usgs.gov/newsroom/article.asp?ID=1767) and (http://www.usgs.gov/newsroom/article.asp?ID=1766)