Saving water for a not-so-rainy day

Reservoir uses off-peak storage to create a new water supply
Water scarcity is — without question — one of the top drivers for One Water. Solutions such as water reuse are ideal for areas like California and the Southwest as they struggle with drought conditions that limit availability of traditional supply sources.

But what about areas where water exceeds storage capacity for part of the year, yet still leaves water managers with unpredictability at other times as populations rise and neighboring agencies compete for limited resources?

In the southeastern United States, which gets a great deal of rainfall in relatively short periods of time, the challenge is to capture and store excess water to quench the thirst of growing cities in the region, and create independent, predictable water supplies.

For Paulding County, Ga., which is part of the metro Atlanta area, the answer is the Richland Creek Reservoir Project. For decades, the county has purchased all of its water from the neighboring Cobb County-Marietta Water Authority, which receives water from Lake Allatoona, a USCOE-controlled reservoir. Lake Allatoona has been the subject of multi-state, decades-long disputes over access and allocations, leaving Paulding County vulnerable to supply restrictions.

The new Paulding County system will withdraw water downstream of Lake Allatoona on the Etowah River.  Although the minimum flow in the Etowah River is 290 cfs, this river can see dramatic increases in flow during periods of rainfall and power generation (with flow exceeding 7,000 cfs).  During periods of high flow, water will be pulled off to support the Richland Creek Reservoir.  During critical periods of low flow within the river, the intake will be turned off, eliminating impact to downstream users.

Using "off-peak” water supplies to fill the pumped storage reservoir represents fresh and exciting One Water thinking, according to program manager Kelly Comstock of Brown and Caldwell. "It’s a win-win for Paulding County and the surrounding region.” he says. "Using an untapped source that results in more water for Paulding County frees up allocation in Lake Allatoona for other jurisdictions as well.”

The approach may even be part of the long-term solution to the ongoing water allocation challenges for Georgia, Florida and Alabama over use of the Apalachicola-Chattahoochee-Flint and Alabama-Coosa-Tallapoosa river systems.

With the Richland Creek Reservoir project, the county will build its own independent water supply and distribution system, with capacity modeled to serve residents for at least the next 50 years. Located on 700 acres of county-owned land, the 305-acre reservoir will be accompanied by a raw water intake and pump station, a raw water pipeline, a new water treatment plant and distribution system improvements.

The reservoir is designed to yield about 35 million gallons per day and will provide about 3.43 billion gallons of water storage to support Paulding County.

"I’ve worked day and night to try to make this happen,” Paulding County Chairman David Austin told CBS Channel 46. "It’s just one of those things that needed to happen for Paulding County to secure our future.”

Katherine Zitsch, manager of the Natural Resources Division of the Atlanta Regional Commission, agrees, noting that the project "will allow Paulding County to pull off of the Cobb-Marietta system, which in turn gives Cobb-Marietta more water for its other customers.”

Has off-peak storage created a new water supply in your area, taking full advantage of times when water is in abundance? Perhaps your community has begun capturing and using stormwater as an untapped supply to counter flooding. What plans are in the works to do so? What are some other solutions to this water challenge? Please share!

About the experts
autor photo
Kelly Comstock is Brown and Caldwell’s Drinking Water practice leader and Program Manager for Paulding County’s Richland Creek Reservoir project.
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