If history is any guide, 2012 is shaping up to be a dry and dismal year, especially for upstate reservoirs along the Savannah River.
According to data kept by the U.S. Army Corps of Engineers since 1954, Thurmond Lake’s average pool for April – 322.2 feet above sea level – is already 5.6 feet lower than this time last year.
Lower April pools were recorded just five times in 58 years, coinciding with some of the worst droughts on record, in 1955, 1988-89, 2002 and 2008.
Part of the culprit this year has been a persistent La Nina weather pattern that lingered through the winter into spring.
“That’s why March was so warm and so dry,” said Georgia State Climatologist Bill Murphey, whose most recent forecast calls for little relief in coming months.
“The anticipation is still drier than normal and warmer than normal,” he said. “Normally, we expect a lot more precipitation this time of year.”
According to the National Drought Mitigation Center in Nebraska, much of Georgia – including the eastern portion of the state around Augusta – already is experiencing “extreme drought” that could worsen if more rainfall doesn’t materialize soon.
“Isolated thunderstorms don’t do it,” Murphey said. “You need that long, gradual soaking rain that helps put moisture back into the soil, and right now we don’t seem to be getting much of that. Everywhere you look, stream flows are still very low and groundwater conditions are dry, too.”
The Corps of Engineers is already looking ahead to a dry year and is working to modify its Drought Management Plan, which is designed to soften the impact of droughts that have created drastically low lake levels in past years.
The newest version of the plan, released Friday for public comment, calls for further – and earlier – reductions in flows from the lake into the Savannah River as lake levels fall.
The plan would also leave lower flows intact for longer periods, slowing the lake’s decline and making recovery easier when rainfall resumes.
Regardless of what plans are in place to manage drought, the only resolution is abundant and immediate rainfall, which both Murphey and South Carolina State Climatologist Hope Mizzell believe is unlikely.
Stream flows in South Carolina counties that adjoin the lake and other Savannah River reservoirs are less than 25 percent of normal, Mizzell told The Associated Press.
Without the winter and spring rains that recharge lakes and groundwater reserves, the best hope for enough precipitation to rehydrate the region lies with tropical weather systems that could arrive in late summer or early fall.