August 24, 2022 436 PM
Located beneath Culberson County, the Lobo Management Area of the West Texas Bolsons Aquifer has long been pumped to irrigate crops in the southwestern corner of the county. Water levels in the aquifer have been in decline for years, and the Culberson County Groundwater Conservation District (CCGCD) has been working for some time now to mitigate these impacts. According to Summer Webb, CCGCD general manager, the district began curtailing permit holders to 3 acre-feet per year on a trial basis in 2018 in response to significant drawdown in the aquifer. Those limits have now been extended for another three years.
Other efforts to slow the decline of the aquifer involve increasing the efficiency of irrigation practices. The district has encouraged irrigators to move away from pivot sprinklers and toward microsprinklers and drip systems. Flood irrigation practices can also be more targeted to reduce water usage. While Webb thinks there is much potential to “apply the water better,” she also warns that “retrofitting these irrigation systems is very expensive.” And it will take time before these systems are in place.
Despite the many challenges, Webb says her permit holders have been very good about compliance with the district’s attempts to slow the decline of the aquifer. “They realize it ultimately benefits them,” she says. “But will the aquifer recover? No. Unless we reduce pumping and get a significant increase in rainfall.”
While nobody can control how much rain falls, one of the options the district is exploring could have an impact on how much stormwater reaches the aquifer. Known as “managed aquifer recharge,” the approach offers “a lot more local potential” to recharge the aquifer in a targeted manner, says Webb. Toward this end, the CCGCD has authorized its hydrologist, Steve Finch, to begin a study to identify the most effective recharge zones in the Lobo Management Area.
According to Finch, “We will be looking at basic modifications of stormwater channels to get more infiltration [into the ground] rather than runoff.” The goal is to “minimize the effects of pumping” for agriculture and make it “more sustainable.” Landowners have been using similar practices for a long time now. “Ranchers can be pretty innovative,” said Finch, with the use of “spreader dams.” These simple berms can be constructed near a water channel to direct flow away from the channel and toward open fields to irrigate native grasses. These pastures are then used to support more cattle. These “spreader dams are also suitable for retrofitting for the purposes of managed aquifer recharge [and] they’re all over the place” in that region of Culberson County.
In concrete terms, Finch will be looking at soil and geology to locate the best spots where stormwater can most rapidly soak into the ground and enter the aquifer before it evaporates. Managed aquifer recharge is a common water strategy employed by municipal water utilities throughout the Southwest, explains Finch, because it has been “demonstrated to be very effective.” What makes this project unique, according to Finch, is that managed aquifer recharge “has not yet been put to widespread use specifically for irrigated agriculture.”
Webb and Finch both stress that the ultimate success of the project will come down to stakeholder involvement. “With enough landowner engagement and community engagement, the study shouldn’t take long at all,” says Finch. Webb is convinced that public involvement will be key. “There’s a lot that goes into this, and so we’re asking people for input,” stated Webb. “There are laws we have to follow, of course. But we also need to improvise a little here and see what will ultimately work.”
If current trends continue, Texas could experience significantly shorter wet seasons and more frequent and prolonged droughts. Landowners, agencies and average citizens will need to work together more closely than ever to brace for the impacts of a changing climate. Despite the challenges ahead, Webb and Finch are optimistic about the potential benefits of managed aquifer recharge.
“We are not offering pie in the sky here with this approach,” said Webb. “But we think it could potentially help the situation and we want to make sure everyone is aware of the issue. That’s what this study is all about.”
Trey Gerfers is a San Antonio native and serves as board chairman of the Presidio County Underground Water Conservation District. He earns his living as a translator of technical documents from German to English for the German and Swiss pharmaceutical and medical-science industries. Trey has lived in Marfa since 2013. He can be reached at [email protected]