Desired Future Condition for Carrizo/ Wilcox Aquifer

By Legislative mandate every five (5) years the Groundwater Conservation Districts of Texas must establish a Desired Future Condition for their particular aquifer or aquifers. Under “managed depletion” each district in conjunction with neighboring GCD’s must determine what their aquifers will look like in the next 50 years.

Note the term, “managed depletion” means virtually every aquifer in the United States is being depleted faster than it is recharged. This simply means every year there will be less water stored in the aquifer than the year before. Under the Texas Water Code each district must decide how this is to be managed. Some districts limit drawdown, others manage how much water remains in underground storage, and other districts monitor drawdown and adjust pumping if needed.

The Evergreen District is in Groundwater Management Area 13 and is working for a consensus with the surrounding districts to protect the outcrop and recharge zone from significant drawdown. The outcrop and recharge zone is sensitive to over-pumping from both the outcrop/ recharge and deeper Artesian zones. Depletion of the outcrop/recharge zone will not recharge quickly leaving some users with a limited source of underground water for the foreseeable future.

State law requires that GCD’s treat ALL requests for drilling and pumping permits fairly and equally no matter whether the request is from district residents or outside interests. And this is where the problem begins for this DFC. The $2Billion “SWIFT” fund that voters approved last year has led to a number of requests from outside interests for large pumping projects in the GMA 13 area including the four (4) county Evergreen Conservation District.

GMA 13 (including the Evergreen GCD) has requested that our consulting geologist/hydrologist determine the effect each pumping project will have on the outcrop/recharge zone.

We are awaiting his modeling study. There are potentially six (6) projects in the Evergreen District that could affect the Carrizo/ Wilcox aquifer. If any of these proposed projects could cause significant drawdown the option to limit them must be a serious consideration by the districts of GMA 13.

Note that the Guadulupe river authority is concerned that drawdown in the recharge/outcrop could have negative effects on Guadulupe River flow. Less water flowing downstream will impact downstream users and bays (estuaries).

Please stay tuned for further developments as GMA 13’s Desired Future Condition is due May 1 to the Texas Water Development Board for review.

Jay Troell, P.E.

Atascosa Director – Evergreen UWCD: Please note the above comments are my opinion and may not reflect the Evergreen’s board position.

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