GBRA letter shows organization wants to take even more Carrizo groundwater
Request comes after GCUWCD board denied export and production increases
On Aug. 15, 2025, I attended a joint planning meeting held by the Groundwater Management Area 13 (GMA13). GMA13 oversees joint planning for aquifers across South Central Texas, including the Gonzales County Underground Water Conservation District (GCUWCD), which covers most of Gonzales County and the southern part of Caldwell County.
Its members include groundwater districts from Atascosa, Bexar, Caldwell, Comal, Dimmit, Frio, Gonzales, Guadalupe, Hays, Karnes, La Salle, McMullen, Medina, Uvalde, Wilson, and Zavala counties. GMA 13 uses groundwater modeling to set Desired Future Conditions (DFCs) for aquifers, promoting sustainable management, balancing water needs, and protecting the environment.
Every five years, GMA 13 must conduct joint planning, including calculating Modeled Available Groundwater (MAG), the annual water volume that fits the DFCs.
For local residents, farmers, and stakeholders reliant on the Carrizo aquifer, this state water planning process is the frontline defense against over-pumping by exporters that cause irreparable harm to our aquifers. This is where the groundwater exporters plug in their desired projects as a way to help gain approval of permits, finance more export pipe with state money, and expand their water sales. This process is controlled by the exporters and the Texas Water Development Board.
GMA13's presentation mentioned a letter from exporter Guadalupe-Blanco River Authority (GBRA) dated July 24, 2025 to GCUWCD general manager Laura Martin-Preston. GBRA requested that 41,000 acre-ft/yr of pumping from Gonzales County UWCD be included in the plan update.
Review of the GBRA letter shows it was signed by Charles M. Hickman, P.E., GBRA’s Executive Manager of Engineering, and carbon copied to Darrell Nichols, the GBRA General Manager/CEO, and Joe Cole, the GBRA General Counsel.
GBRA's letter is aggressive: "GBRA currently exclusively leases Carrizo Aquifer groundwater rights beneath over 41,000 acres of land in Caldwell and Gonzales Counties, within GCUWCD’s boundaries. Per GCUWCD rules, the maximum permitted production for a tract of land may not exceed one acre-foot per year of Carrizo Aquifer water per surface acre of land owned. GBRA’s maximum allowable production based upon current property rights and GCUWCD rules is over 41,000 acre-feet/year."
Further, it states: "GBRA hereby provides notice to the GCUWCD that it plans to put to beneficial use the entirety of its permissible production to meet the growing demands for water within GBRA’s jurisdiction." Invoking Texas Water Code § 36.108, the letter says DFCs must consider the "highest practicable level of groundwater production," urging inclusion of the full 41,000 AFY in updates slated for adoption in January 2027.
Remarkably, the GBRA letter also states: "The 2026 Texas Regional Water Plan – Initially Prepared Plan, dated March 3, 2025, includes both GBRA’s 15,000 acre-feet/year of production, based upon projects with existing water contracts and facilities that have already been constructed or are currently in construction, and the additional 9,000 acre-feet/year of production that GBRA has requested authorization to produce and that GBRA has already contractually agreed to supply to Goforth Special Utility District, County Line Special Utility District, Maxwell Special Utility District, and Camino Real Utility."
GBRA's letter comes well after the GCUWCD board's vote on June 10, 2025 to deny GBRA's request for that additional 9,000 AFY of Carrizo groundwater, following a contested hearing amid strong public opposition.
GBRA's requested 41,000 AFY is massive and unsustainable. For reference, a recent groundwater model estimates the annual recharge from precipitation to the Carrizo-Wilcox Aquifer for the GCUWCD to be just 7,855 AFY. Only a minor fraction of rainfall actually reaches the aquifer as recharge.
GBRA's desired 41,000 AFY is over five times the annual precipitation recharge rate. This does not include the other exporter permit volumes. Total permitted volumes granted by GCUWCD for the Carrizo aquifer already exceed 92,000 AFY. This is referred to as "mining" of stored groundwater, similar to oil, since the extraction rate far exceeds natural replenishment.
GBRA's letter shows no respect for the GCUWCD board decision or local residents. Further, GBRA shows zero concern for recent groundwater modeling or best available science that shows already permitted volumes for the Carrizo aquifer are not sustainable. It's hard to comprehend how GBRA's groundwater projects are funded using the state's money when intended pumping volumes are in excess of the aquifer's actual capacity to produce long term.
The district board will meet at the Courthouse at 5:30 p.m. Tuesday, Sept. 9. The public is encouraged to attend and ask the board members to formally reject GBRA's position to take more groundwater from Gonzales County and to send written notice to GMA13.
Ted Boriack is a member of the Water Protection Association and a Gonzales County landowner dedicated to preserving local water resources.
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