NewsDrop-May-June-2026

AQUIFER MANAGEMENT SERVICES | FEATURED STORY

Figure 1: Modeling projections of future groundwater levels at the J-17 index well with and without the mitigation strategies employed by EAA (Sharma, et al., 2024) 2 . Critical Stage (CS) thresholds of CPM are denoted.

Figure 2: A plot of duration and intensity (average depth below CS1) of Edwards Aquifer droughts since the 1930’s. Those lasting more than one year (including our current drought) are labeled.

One of the most effective regulatory tools we employ is the EAA Critical Period Management Plan (CPM). CPM requires graduated reductions to permitted withdrawals based on aquifer levels or springflows during drought. Recent modeling results, shown in Figure 1, compare a future climate scenario using models with (blue) and without (green) CPM applied. The results indicate that median and minimum water levels would be significantly lower without these regulatory strategies in place.

• Regional Conservation – another measure in which more than 10,000 ac-ft of water is conserved by multiple partner organizations, including the EAA. This is achieved by leak detection programs, upgraded irrigation systems, public awareness/education, water conserving plumbing fixtures, and similar efforts. Together, these management tools help to ensure that minimum springflows are maintained for the protection of endangered species, while also maximizing the availability of water for users across the region. The current drought The Edwards Aquifer region has been mired in drought for the last several years. Perhaps there is no better example of the effectiveness of EAA’s management strategies than how the aquifer has fared during these challenging conditions. The current drought is the result of a combination of persistently limited rainfall and high temperatures. As seen in Figure 2, the current drought is the second longest on record and the most intense; water levels today are lower than they have been during previous droughts. In other words, the 1950s drought of record was nearly twice as long as the current drought, but water levels over the past 4 years have been consistently lower.

Despite these unrelenting drought conditions across the Edwards Aquifer region, Comal and San Marcos springs have continued to flow. This resilience can largely be attributed to CPM, VISPO, and regional conservation strategies that have been sequentially initiated as the current drought has progressed. CPM reductions began in the Uvalde pool in June 2022 and in the San Antonio pool in March 2022. Forbearance of irrigation by participants in the VISPO program has been in effect since 2024. Recharge to the Edwards Aquifer has steadily declined, with the updated 10-year average falling below the 500,000 ac-ft trigger needed to initiate ASR forbearance and ASR use in 2027. With each additional measure in place, the EAA has demonstrated that management strategies help us maintain springflows and water availability even during these unprecedented conditions. Conservation measures and strategies are necessary to sustainably manage the Edwards Aquifer. Our permitting system, combined with management strategies informed by extensive data collection and modeling efforts, enables permit holders

to maximize use while aquifer levels are also maintained to sustain springflows at Comal and San Marcos springs. Without an effective management system in place, aquifer levels would be far lower during extended periods of drought like we are experiencing now. Aquifer management, the central role of the EAA, has proven to be a success. End Notes 1. One acre-foot is equal to approximately 325,851 gallons of water. 2. Sharma, C., H. Başağaoğlu, I. Yoosefdoost, A. Wooten, D. Chakraborty-Reddy, F.P. Bertetti, A. Mirchi, and D. Chakraborty. 2024. Efficacy of mitigation strategies for aquifer sustainability under climate change, Nature Sustainability, vol. 8, pp. 44–53. https://doi.org/10.1038/s41893-024-01477-6

Other management tools are employed alongside CPM. These voluntary measures include:

• Voluntary Irrigation Suspension Program Option (VISPO) – this program compensates enrolled holders of irrigation permits. Compensation is either for enrollment (standby payment) or forbearance of water during drought. • San Antonio Water Systems (SAWS) Aquifer Storage and Recovery (ASR) – the ASR provides for long-term storage of Edwards Aquifer water in the Carrizo-Wilcox Aquifer. This stored water can be used in times of critical drought to reduce demand on the Edwards Aquifer by retrieving stored water and introducing it back into the distribution system when needed most.

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