Raleigh’s search for new water supply ends at Falls Lake
If you’ve lived in the Triangle for a while, you may remember a time when you took for granted that the region would always have enough drinking water. And you may remember the year that no longer seemed to be true.
The drought of 2007 was the worst on record in the region. Water levels in Falls Lake, the main water supply for Raleigh and six Wake County towns served by the city’s utilities department, dropped 10 feet, exposing acres and acres of dried lake bottom. Yards turned brown, people shortened their showers and put bricks in their toilets to save water, and rain barrels became a hot item. Drinking water had suddenly become more precious.
A year earlier, the City of Raleigh had set out to find a new source of drinking water to keep up with its growing population. The city’s water comes from three reservoirs — Falls Lake, Lake Benson and Lake Wheeler — and as the drought of 2007 made plain those lakes aren’t getting any bigger.
The city looked at more than two dozen potential options, including drawing water from Jordan Lake and the Neuse River downstream of the city. It even looked at running pipelines as far away as Kerr Lake to the north and down near the coast, where it could tap into fresh groundwater that is pumped from a phosphate mine.
A few years into the search, the city’s engineers decided that one of the least likely options might just be the easiest and cheapest, if they could persuade the U.S. Army Corps of Engineers to let it happen. What if the federal agency would let the city take more water out of Falls Lake?
Raleigh had purchased the rights to 42.3 percent of the capacity of Falls Lake that isn’t needed for sediment or flood control. The other 57.7 percent was reserved to maintain the flow in the Neuse River, so communities and the river ecosystem downstream would have enough water.
Once the Corps has settled on how the water in one of its lakes has been divvied up, it seldom makes changes, says Kenny Waldroup, the assistant director of Raleigh’s public utilities department. To give one interest group more water usually means giving less to another, and reallocation decisions often end up in court, Waldroup said. A reallocation request by utilities in the Atlanta area seeking to draw more water from a lake in northern Georgia has been held up by lawsuits and other delays for 38 years.
But Raleigh engineers thought they had a good case after they realized that the gauge the Corps uses to determine how much water from Falls Lake flows downstream is in Johnston County, downriver of the city’s wastewater treatment plant.
Raleigh could show that 85 percent of the water it draws from its lakes on average gets returned to the river through the treatment plant. The city isn’t taking the water out of the Neuse River basin so much as it’s borrowing it.
In 2013, the city asked the Corps of Engineers to consider giving Raleigh credit for the water it returns to the river and let it draw more from Falls Lake. Given the Corps’ experience with reallocations elsewhere, it seemed a tough sell, Waldroup said.
“We were certain reallocation would work,” he said. “We weren’t certain we could convince anybody else.”
At the time of the big drought in 2007, the city’s need for a new water supply seemed urgent. The year before, when Waldroup joined the city from the town of Zebulon, he was assigned to work on the Little River Reservoir that would be created by a new dam in northeastern Wake County. Construction was scheduled to begin in 2016 and finish the following year.
But then something happened that gave the city more time to consider its options: People started using less water. In 2007, the city and the six towns were consuming 117 gallons of water per person each day; by 2013, that had fallen to 92 gallons. Last year, it had declined to 86 gallons. As a result, the city and towns are using less water now than before the drought, despite the population in its service area growing by more than 120,000 people in a decade.
The drought had much to do with the change in consumption. The long dry spell and the emergency conservation measures put in place to extend the dwindling water supply seemed to make people think differently about water, said Ed Buchan, the environmental coordinator for the utilities department.
“The constant media barrage, I think, had an impact, and people just didn’t return back to their old former habits,” Buchan said. “That’s especially true when it comes to irrigation.”
Landscapers and homeowners began using more drought-tolerant plants and grasses. Lawns shrank in size or were eliminated altogether. Before the drought, it wasn’t unusual for water consumption to spike by 20 million gallons, or 40 percent, on hot summer days.
“We don’t have any type of major spike like that,” Buchan said. “At least we haven’t since 2007.”
Other factors have helped reduce demand for water, Buchan and Waldroup say. A growing share of new residents are living in apartments and townhouses, with little need for irrigation. And new toilets and appliances all use less water than the ones they replace.
“It’s very difficult nowadays to purchase a toilet that is not already low flow,” Waldroup said. “The dishwasher in a new home uses much less water than the dishwasher in an old home.”
And finally, in 2010, the city stopped offering volume discounts for water. Residents are now encouraged to use less water with tiered rates that go up as consumption increases.
“The cumulative effect of all of those things is we need less water per capita,” Waldroup said.
The Corps decides
But with state demographers estimating that Wake County’s population will grow by another half-million people in the next 20 years, conservation can only delay the need for new water supplies for so long. The city expects daily demand in its service area to nearly double by 2047, to about 98 million gallons per day.
The Army Corps of Engineers office in Wilmington spent two years studying the city’s request for more Falls Lake water. In the end, it determined that allowing Raleigh to take more water wouldn’t interfere with what the Corps considers the main mission of Falls Lake — to control flooding downstream, said spokeswoman Lisa Parker.
“An evaluation of alternatives indicated the plan would benefit numerous parties without compromising the flood risk management Falls Lake and Dam provides,” Parker wrote The News & Observer in an email. “There will be insubstantial effects on environmental resources due to water coming from existing storage and being returned downstream.”
In January, 13 years after Raleigh began searching for a new supply, the Assistant Secretary of the Army for Civil Works signed a contract granting the city the equivalent of an additional 22 million gallons of water a day. Added to the current available supply of about 75 million gallons a day from all three lakes, the city says it now has enough water to meet expected demand through 2047.
Which isn’t that far away when it comes to water planning. City officials know that finding the next source of drinking water won’t be as easy or cheap as it was this time. The city will pay the Corps of Engineers $24 million for the rights to draw the additional water from Falls Lake. That compares to an estimated cost of more than $350 million to build the Little River Reservoir, which will likely be at or near the top the list of future water sources for the city.
Waldroup says the utilities department will wait a few years to see if consumption patterns change, then will start the whole process over again. In the meantime, Raleigh will join other utilities to begin working on a water supply plan for the entire region, including Johnston and Harnett counties.
The Triangle Water Supply Partnership is growing out of a similar joint effort that determined how Jordan Lake’s water will be shared among a dozen communities and utilities. The partnership will look at how the region can make the most efficient use of its limited water supplies and perhaps create new ones, said Sydney Miller, the water resources planning manger for the City of Durham.
“The Triangle has been growing and is expected to continue to grow. It’s not clear that the available supply of water will grow,” Miller said. “And even though our communities are becoming more efficient in their use of water, there’s an expectation that we’re going to be using more of it.”