City firming up request for more Jordan Lake water

May. 03, 2014 @ 03:59 PM

To meet long-term needs, Durham needs a bigger allotment of Jordan Lake water, to the tune of nearly a two-thirds increase on its present reserve, the city Water Management Department told state regulators.

Officials will formalize the application for an additional 6.5 million gallons a day reserve of Jordan water in the fall, but signaled their intentions on Thursday by submitting a draft of the proposal to the N.C. Department of Environment and Natural Resources.

The city already has rights to 10 million gallons a day of Jordan water, and wants more because the 2007 drought showed its own two reservoirs, Lake Michie and Little River, aren’t as up to meeting future demands as officials once thought.

Before the drought, engineers figured the northern Durham lakes could reliably deliver 37 million gallons of water a day.

But the drought, the worst on record, forced a new reckoning that has dropped the estimated “safe yield” of the city reservoirs to 27.9 million gallons a day.

That includes a “safety factor” of roughly 20 percent, said Vicki Westbrook, assistant director of the Water Management Department.

Durham’s current allotment of Jordan water helped the city make it through the 2007 drought, when Lake Michie and the Little River Reservoir between them held less than two months’ worth of high-quality supply.

To tap the allocation, the city now has to work with nearby Cary, which has the only existing water intake on the regional reservoir. Cary draws and treats the water, and then sells it to Durham.

Long-term, however, the plan is to build a new intake, treatment plant and piping network on the western side of Jordan Lake in cooperation with utilities in Chatham and Orange counties.

The project would unfold in phases, and be designed to handle the area’s needs through 2060. Early estimates are that it could cost $312 million, with Durham picking up $115 million of the tab, Water Management said in its draft submission to DENR.

Chatham County and Pittsboro would contribute another $148.6 million, all presuming local governments in the coming couple of decades are up to the “politically complex” task of negotiating a cooperation pact.

The project would clearly be a long-term effort, Durham officials figuring their city can get by on the existing reservoirs and Jordan allocation until about 2040.

Jordan isn’t the city’s only long-term water-supply expansion possibility, but Water Management believes it’s the most feasible of those now under consideration.

It’s possible, for example, to build a bigger dam at Lake Michie, a $158-million-to-$203-million move that could nearly double Durham’s city-owned water stockpile.

But that would be an even tougher challenge politically “due to the likely degree of opposition by environmental protection advocates,” Water Management said.

The Lake Michie option and a different possibility, expanded use of the city’s Teer Quarry backup supply, could attract opposition from Raleigh officials. Either alternative could reduce water flow into Falls Lake, the capital city’s supply source.

The city could also massively expand the use of “reclaimed water,” laying a piping network so the recycled effluent of its sewage-treatment plants can be used for irrigation or industrial processes.

But that raises the same flow-into-Falls-Lake problem as the Lake Michie and Teer Quarry options, and additionally could provoke “widespread citizen complaints” because of the necessary in-town construction, Water Management said.

DENR’s Division of Water Resources and the state’s Environmental Management Commission control allocations of Jordan water to area communities. They opened the door in 2010 to new applications and may make a decision on them late in 2015, Westbrook said.