The city council voted Tuesday to seek permission to pull more drinking water from Falls Lake, a move that would postpone Raleigh’s need to build a new reservoir in eastern Wake County.
Raleigh supplies water to 500,000 people in Raleigh and six smaller Wake County towns. The number of customers is expected to double within 30 years, putting a major strain on the water supply from Falls Lake. The city had long projected the need for a new reservoir on the Little River.
Tuesday’s vote calls on the Army Corps of Engineers – which oversees the lake – to study the impacts of allowing Raleigh to draw water from another 3.8 percent of the lake. The city will pick up the tab for the study, which is estimated to cost $450,000.
“Even with the most aggressive water conservation and efficiency gaols, we recognize that we will need new water resources,” said assistant public utilities director Kenny Waldroup. “This alternative could provide those resources for the next 30 years.”
While Raleigh is the primary user of Falls Lake, it doesn’t get to use all of it for drinking water. A percentage of the lake’s capacity is reserved for flood control, while other chunk is a “water quality storage pool,” monitored to ensure there’s enough water to dilute pollutants.
Raleigh’s request would decrease the water quality share, reducing the amount of water that stays in the Neuse River downstream. But Waldroup points out that as much as 87 percent of the water the city takes from Falls is returned to the Neuse at the wastewater treatment plant.
Communities downstream that use the Neuse River as a water supply will weigh in on Raleigh’s proposal.
“The city of Raleigh must consider those impacts and try to quantify them,” Waldroup said, adding that a study will also determine effects on water quality in the lake.
If the Corps of Engineers agrees to the study, getting results will take one to three years, Waldroup said. If the findings reject the increased water allocation, Raleigh will then consider drawing water from the Neuse downstream of the Falls Lake dam, using quarries.
“Those have significant social, economic and environmental impacts,” Waldroup said, noting that using a larger percentage of water from the lake is a less disruptive option.
If the city can’t get more water from the Neuse River basin, estimates indicate the Little River Reservoir will need to be in operation by 2024. If the city and county end up damming the Little River for more water, the project is expected to cost an estimated $263 million and could damage endangered species and other habitats.