Should States Invest In Underground Water Storage?

Are drought-plagued states missing the opportunity to store rain when it comes their way?

A Texas lawmaker says yes, arguing that building the capacity for more underground water storage would help his state, which faces recurring water-scarcity challenges.

A four-year drought ended in Texas last year, but experts say scarcity remains a threat. The population is expected to grow in many areas of Texas in the coming decades, putting additional strain on the supply.

Texas Rep. Lyle Larson, a Republican from San Antonio, is working on a bill that he says will help “drought proof” the state.

“The idea is to build a network of underground reservoirs to capture excess water as it rushes down Texas rivers, instead of allowing it to flow into the Gulf of Mexico. Eventually, Larson hopes, the reservoirs would be able to hold enough water to get Texas through a seven-year drought,” the Corpus Christi Caller-Times reported.

Larson is calling for "aquifer storage and recovery" facilities. He compared the structures to the Strategic Petroleum Reserve, “referring to massive federal stores of crude oil meant to guard against supply crises such as those that occurred in the 1970s,” the report said.

El Paso, San Antonio, and Kerrville already have water storage structures, the report said, and more are being built under state grants. Buda, TX, recently approved a $100,000 study investigating if aquifer storage and recovery is feasible for its own needs, the Hays Free Press reported.

"If you can save tens of millions of acre-feet a year, it will change the water paradigm," Larson said, per the report. "You can drought-proof your state."

San Antonio's Twin Oaks Aquifer Storage and Recovery Project is one example. The San Antonio Water System “stores excess Edwards Aquifer drinking water during rainy times in a large-scale underground water storage facility in south Bexar County for use during our dry South Texas summers,” the utility explains, noting that aquifer storage and recovery technology is “relatively new.”

The advantages of this approach, per the utility:

• Environmentally friendly method of storing Edwards Aquifer drinking water in the Carrizo Aquifer;
• Water stored during the year can be used during dry, hot months;
• Maximizes use of pumpage allocations from the Edwards throughout the year;
• Underground storage means no evaporation;
• Less vulnerable to contamination than surface storage;
• Most land directly above the underground reservoir can continue its prior use.

Nevertheless, environmentalists and water managers have issued words of warning about viewing underground storage as a perfect solution to water scarcity. The Caller-Times reported:

In prepared notes for a legislative hearing on Thursday, Ken W. Kramer, water resources chairman of the Lone Star Chapter of the Sierra Club, acknowledged that Larson's plan to store water underground would avoid evaporative losses, saying such storage "should be strongly considered for major storage of water." However, Kramer said, any plan must be careful to protect "environmental flows" — the share of water needed to support the ecosystem in and around Texas waterways.

To read more about potential solutions to drought visit Water Online’s Water Scarcity Solutions Center.