Raleigh, N.C. — City officials are working with the Army Corps of Engineers on a plan to pump water from Lake Benson and Lake Wheeler into the Neuse River to conserve Raleigh's dwindling drinking water supply in Falls Lake.

The city has proposed pumping about 202 gallons per second from Lake Benson into the Neuse River near Auburn-Knightdale Road, using a new pump station and 10 miles of sewer force main. Because neither the pump station nor the sewer lines have been used yet, there shouldn't be an adverse environmental impacts, said Dale Crisp, director of Raleigh's Department of Public Utilities.

The Corps of Engineers and the state Department of Environment and Natural Resources haven't yet approved the plan.

The water from Lake Benson and Lake Wheeler – it empties into Lake Benson through Swift Creek – would allow lower discharges from Falls Lake, the primary reservoir for Raleigh and several Wake County towns. Crisp estimated that the move could add up to three weeks to the available water supply at the lake.

But Ed Buchan, a water conservation expert with the Department of Public Utilities, said Lake Benson and Lake Wheeler can be lowered by no more than 10 feet each by the pumping.

The alternative flow to the river would be the latest step for Raleigh in its effort to conserve the water supply at Falls Lake, which was more than 8 feet below normal on Wednesday. The lake was about 6 inches from its record-low level, reached two weeks ago, and has at least 115 days of water left, Crisp said.

Stage 1 water restrictions were adopted in late August to reduce outdoor watering to two weekdays and on weekends. Two weeks ago, the city implemented "Stage 1.5" restrictions, banning sprinklers for lawn watering and personal car washing.

Since the tighter rules went into effect, average daily water demand has fallen by 22 percent, from 52.8 million gallons to 41.2 million gallons, officials said.

The city has been moving ahead with plans to bring Lake Benson into the city's drinking water system to add supply, but that project is still in progress. The lake was once a water source, but the city abandoned it when the Falls Lake system became the main source.