Aquifer Storage: A Promising Part of Texas Water Solutions

August 4, 2014 by Brad Lingvai

Aquifer Storage: A Promising Part of Texas Water Solutions

Among the state’s water supplies, aquifers are a critical source of water for Texas. According to the Texas Water Development Board, Texas has nine major aquifers that produce large amounts of water over large areas, and 21 minor aquifers.

Beyond supplying water, aquifers may also play a key role in future water management for the state through aquifer storage and recovery (ASR).

With ASR excess water is injected into sand aquifers, and stored there until it’s needed in a time of drought.

This blog post is part of an 8-part series that will be published throughout July and August. Visit our Water in Texas page to read all of the articles.

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“ASR is desirable because the storage is underground, and there’s no evaporation. Environmentally, it doesn’t change the surface of the land. With a surface reservoir, those are big issues — evaporation and environmental challenges,” Dr. Calvin Finch, director of the Water Conservation and Technology Center, said in a Texas Water Resources Institute article.

ASR
Aquifer Storage and Recover Graphic Courtesy of “Plant a Seed and Watch it Grow”.

For Texas, ASR is a relatively new technology, but one that holds great promise. According to a 2011 Texas Water Development Board report, Texas will need almost 9 million acre-feet of new water per year by 2060. “It will be difficult for conservation and other traditional strategies, especially expensive, controversial surface reservoirs, to meet all of that demand,” the report’s executive summary notes. “The capture and storage of water when it is available is critical to sustainable water management. The escalating costs and environmental challenges associated with surface water reservoirs have encouraged water professionals to explore ASR.”

Evaporation is a huge hurdle when it comes to surface water storage. During the 2011 drought and heat wave, Lake Travis lost 206,000 acre-feet to evaporation, significantly more than the 166,000 acre-feet the city of Austin drew from the lake. That same drought has spurred 13 study areas around Dallas that could become ASR sites.

Although Texas has not widely adopted ASR, there are two cities that are using it currently: San Antonio and Kerrville.

The San Antonio Water System (SAWS) takes extra, permitted water from the Edwards Aquifer when water levels are high, and pumps it into the sandy Carrizo Aquifer. The Carrizo is a more stable place to hold the water – water in a sand aquifer tends to stay put, or move very slowly. SAWS currently has about 90,000 acre-feet of water stored, and can store up to 120,000 acre-feet. (One acre-foot equals 326,700 gallons).

The city of Kerrville has been storing excess Guadalupe River water in its Lower Trinity Aquifer ASR system since 1990, and the city has two wells. Kerrville’s target storage is 4,600 acre-feet.

El Paso also uses a system that is similar to ASR, but instead of using the same wells to take water out and put it back in, the city treats wastewater to drinking water standards, puts it in the aquifer and lets it flow through the aquifer until it comes out of an existing production well.

El Paso Huelco Bolson
El Paso Water Utilities’ infiltration basin recharges the Hueco Bolson Aquifer. Photo courtesy of El Paso Water Utilities

TWDB officials thinks ASR will become more prevalent in the future. Some legislators think so, too. Rep. Lyle Larson, R-San Antonio, authored HB 3013 during the 2013 legislative session to “encourage the development of aquifer storage and recovery projects throughout Texas by establishing a legal and regulatory framework that reflects the technical application of this technology.”

Larson and others hope that getting a policy framework in place will help the technology progress in Texas, as demand for water grows.

 

We want to hear from you….leave your comments, opinions, and other thoughts about water and economic development below!

Visit our Water in Texas page to read all of the articles in this special BIG RED Blog series.

 

Written by Brad Lingvai

Brad Lingvai

Mr. Lingvai is the Commercial Services Market Leader in the BIG RED DOG Austin office. He is also a co-founder of the firm and has been a leader on hundreds of central Texas projects since the founding of BIG RED DOG in 2009. Austin-area projects of note that have benefited from his expertise include Belterra, Waller Creek, the Robert Mueller Municipal Airport (“Mueller”) redevelopment project, and The Domain shopping center. He has extensive experience with design and coordination of water, wastewater, and drainage studies and systems, water quality and detention ponds, and conceptual layouts of gas, electric, and telecommunication lines. Mr. Lingvai received his Bachelor of Science in Civil Engineering from the The University of Virginia (Charlottesville, VA) and is registered as a Professional Engineer in the State of Texas.