The Role of Agriculture in the Diminishing Ogallala Aquifer on the Southern High Plains: A Hydrogeologic Perspective

With over 95% of Ogallala aquifer groundwater used by the agriculture community, the future of the Ogallala is clearly in the hands of the agricultural sector. Recognizing diminishing supply for at least 60 years, programs have been implemented to improve irrigation efficiency, reduce runoff, provide water use education, enhance precipitation through cloud seeding, construct geo-fabric liners in playas to increase recharge, develop drought resistant crops, etc. None of these attempts to reduce the rate of groundwater depletion, neither by themselves nor collectively, have been able to ebb the tide of diminishing supply.

Faced with water shortages throughout the State of Texas, the 2005 Legislature enacted law (HB 1763) that drastically altered the way groundwater is to be managed. No area will be harder hit than the area overlying the Ogallala aquifer, since it's by far the largest aquifer in the state, supporting a water dependent ag economy in a semi-arid environment without the benefit of surface water or significant recharge.

HB 1763 requires the groundwater conservation districts, which consist of small boards of elected officials (primarily farmers), to decide the “Desired Future Condition” (DFC) of the Ogallala aquifer. The choice: how much water will they leave in the Ogallala aquifer in 50 years for use by future generations - 10%, 50%, or perhaps 100% (thereby sustaining the aquifer's current volume)? Once the DFCs are decided, the groundwater conservation districts must develop rules protective of their selected target.

For the first time on the Southern High Plains, groundwater will be managed quantitatively. Possible DFC choices are evaluated in this paper from a volume of water in storage standpoint on the Southern High Plains to better understand what changes in water use will be required to achieve the desired goals.