Let’s start thinking about water!

Water reuse in the Hill Country—Lessons from existing reuse facilities in Texas and opportunities to advance reuse in Comal County

As traditional water resources are fully allocated, non-traditional water supplies become more enticing, and water reuse is one of those supplies. Hanes investigates how water reuse could be expanded and managed in Comal County through a water reuse district or the Guadalupe-Blanco River Authority. One motivation for this is to minimize groundwater production and stream discharge of wastewater, which results in 5 times more nitrate and 18 times more phosphate in Hill Country streams.

Hanes summarizes water reuse projects, including direct potable reuse, in several communities across Texas, including San Antonio, Big Spring, Boerne, El Paso, Round Rock, Lakeway, and Fredericksburg. Interestingly, before there was a San Antonio Water System, there was the Alamo Water Conservation and Reuse District, created by the Legislature at the request of San Antonio. Hanes notes that a similar district or districts could be set up in Comal County to consolidate collection and treatment. Hanes didn’t consider direct potable reuse for the Hill Country because it was out of the project’s scope (yet Big Springs’ and El Paso’s projects are discussed) and seemed problematic. Still, Buda, Dripping Springs, Llano, San Marcos, and West Travis County Public Utility Agency have direct potable reuse in the state water plan, with all but San Marcos planning to have it online by 2030. In other words, don’t throw out the DPR with the bathwater! At 30 pages, this is more of a report than a paper and, oddly, includes a legislative recommendation from the Greater Edwards Aquifer Alliance at the end.

Texas water markets—Understanding their trends, drivers, and future potential

Water markets tap into the animal spirits of capitalism to find the highest and best use. While Texas has water markets (folks can buy and sell water), much of that market is hidden from view. Wight and crew tapped into data from the Water Transfer Database, WestWater, and The Nature Conservancy to create a database of over 2,350 individual surface-water transactions (sales and leases) of over 4 million acre-feet between 1987 and 2022 at a total transactional cost of $1.3 billion. Using this data, they made several interesting observations.

More than 250,000 acre-feet have been transferred, primarily through leases, to benefit the environment. More than 93% of transactions were made in the Brazos, Colorado, Guadalupe, and Rio Grande basins. Agricultural water comprised half of all transactions, with two-thirds moving to municipal use and one-third to other agricultural use. Ag-to-ag transactions were predominantly leases, while ag-to-municipal transactions were predominantly sales. They also found that temperature, groundwater levels, and commodity prices for rice and cotton were correlated with water transactions. They found that the number of transactions has increased over the past decade. I gawked a ten-fold increase in leases and two to three times the number of sales since the 2000s. The Brazos market, mostly silent before the 2011 to 2015 drought, jumped into action after the drought. The Rio Grande market has been much more active since 2008. The write-up on the Edwards Aquifer ain’t quite right (the paper confuses the Barton Springs segment of the aquifer with the San Antonio segment, where the vast majority of the Edwards market activity has occurred), but the paper is focused on surface water, so no worries.

Impacts of groundwater pumping for hydraulic fracturing on aquifers overlying the Eagle Ford Shale

As everyone and their third uncle know by now, you need a lot of water to frack a well. Much of that fracking water, at least in Texas, comes from groundwater, and pumping that much groundwater has consequences. Brien and posse rustled up some data and analyzed it to investigate the impacts of producing groundwater from the Carrizo-Wilcox Aquifer to produce oil from the Eagle Ford Shale between 2011 and 2020. They evaluated pumping schedules for 2,500 rig/frack supply wells for 22,500 hydraulic fracking events. The authors found that theoretical impacts to non-rig/frack wells amounted to an average of 0.7 to 22 feet of drawdown at those wells with 5 percent of wells experiencing 66 feet or more of drawdown (note that they calculated drawdown at affected wells and not at the pumping wells). They also analyzed the costs of increased pumping lifts from these effects. They noted that the impacts of production increased from 2011 to 2020, with most impacts in the upper Wilcox, where most pumping occurred. Increased drawdown in the upper Wilcox probably increased cross-formational flow by 5%.