Army Engineers Manage Lakes, Dams During Drought
Posted October 26, 2007
Raleigh, N.C. — With drought drying up water supplies across the state, those who manage North Carolina's lakes and dams – the United States Army Corps of Engineers – have struggled to balance the competing demands for water supply and water quality.
Terry Brown, water control manager for the Wilmington district, said the Corps' goal is to make the best use of supplies in its reservoirs on the Roanoke, Neuse, Cape Fear and upper Yadkin basins.
"It looks like nature could be challenging us to the limit," Brown said. "We are certainly working hard to respond to the 'worst-case' eventuality that we get little or no rain in the coming months."
The Corps manages water flows from Falls Lake, Raleigh's water source. Levels in the lake are more than 8 feet below normal, and without significant rainfall, the lake could reach a zero-water supply balance by mid January 2008.
Despite that threat, the Corps has released more water from Falls Lake this October than it did during the drought in October 2002. Communities downstream depend on the Neuse, Brown said, and flows along that river are at their worst level in the 80 years data has been collected.
"This water serves to make sure that industries ... can continue to operate without causing serious pollution, it ensures that other communities downstream ... are getting good quality water, and it also preserves water flows and quality so that we do not see serious ecological damage, like fish kills," the Corps said in a release.
The Corps is working with the City of Raleigh to make use of former reservoirs, including Lake Benson, Lake Wheeler and Lake Johnson, to keep adequate flows into the Neuse. If January arrives without any rain, engineers are studying taping into the sedimentation pool of Falls Lake.
Dredging Falls Lake is not a practical short-term solution, Brown. Although the drought has lowered lake levels, getting approval to dredge is a years-long process. A government representative must ask Congress to fund an environmental study, which also usually requires local funds and typically takes five years.
"Dredging would only lower the total water level and not add water to storage. Or, as you might put it more bluntly: If we dug a deeper hole right now, all we'd have would be a deeper hole," the Corps said in a statement. "In the long term, dredging could potentially increase storage."
A study is in progress for Philpott and John H. Kerr Lake, key reservoirs in the Roanoke River basin. That study is in its fourth year and is jointly funded by North Carolina and Virginia.
Although levels in Jordan Lake are also close to 5 1/2 feet below normal, Cary, Chatham County and other communities that draw their water from it do not face the "imminent sum situation" those depending of Falls Lake do. That is largely a result of cooperation between the communities and Corps after the drought of 2002, Brown said.
"Inter-community cooperation is also important at this time," Brown said. He pointed to Siler City, which is getting emergency water supplies trucked in by Chatham County.
Personal water conservation is the key to surviving the drought short term – although "nature has the last word," Brown said.
"But working together, we can make water supplies last a little longer. ... Stretching out water supplies may the key to keeping communities and industries functioning."