Let’s start thinking about water!

A hydro-economic approach for quantifying well performance thresholds and recoverable groundwater yields in Texas

In many ways, the Vista Ridge project—the production and 142-mile transport of 50,000 acre-feet per year to San Antonio—is the bleeding edge of the blue rush to the Carrizo-Wilcox Aquifer, an aquifer that conveniently parallels the I-35 growth corridor. A controversial project from its outset with a history reaching back decades, Vista Ridge is the state’s largest public-private partnership for water. In 2022, after their pumps turned on in April 2020, Vista Ridge was again a big topic when household wells in Lee County next door began burning up when water levels declined. Water levels in the Carrizo and Simboro formations declined 400 and 300 feet, respectively, with cones of depression that extended 15 and 25 miles into Lee County, respectively. Young and others address the hosting district’s Groundwater Assistance Program and property rights issues brought up by folks impacted by Vista Ridge’s production, concluding that fair share is not defined in statute nor explained by the courts how to include in permit decisions.

Hydrogeochemical Evaluation of Aquifer Storage and Recovery in Edwards Aquifer

Strange things can happen when waters of different qualities are mixed, or water of one quality is placed in contact with a substrate that is not in equilibrium with that water (think Flint). Therefore, it’s critical to consider water quality issues for aquifer storage and recovery projects.

Simbo presents the results of an evaluation using the brackish part of the Edwards Aquifer to store treated water from the Guadalupe River near New Braunfels. The author found that the host water quality is a sodium-chloride facies due to halite dissolution, while the source water is a calcium-magnesium-bicarbonate facies due to the local aquifer and contact with the riverbed. The analysis suggests adequate flushing and lateral movement of injected water due to faulting.

Development of Complex Patterns of Anthropogenic Uplift and Subsidence in the Delaware Basin of West Texas and Southeast New Mexico

For much of my schooling and career, the dogma has been land subsidence is a one-way street, and that’s down. One could slow or mitigate how much the ground sank, but you couldn’t reverse it, largely because the weight of the sediments and water above were so massive. That’s not to say the ground couldn’t rise due to other geologic reasons (isostatic rebound, anyone?), but fluid injection wouldn’t get you there. Or maybe not.

Hennings and pals show how massive volumes of liquid transfers in the Delaware Basin in West Texas have caused a rollercoaster of land-surface deformation down as well as up between 2015 and 2021. They saw uplift from reservoir swelling, subsidence from reservoir contraction, and the development of linear features suggesting faulting. Parts of the Delaware Basin have risen 3 to 5 inches, while other areas have sunk 4.5 to 7 inches. Broad areas in New Mexico and Texas show land-surface rise and land-surface falls. Falls occur due to fluid extraction, while rises occur due to fluid injection, generally in shallower formations. The amount of over-pressuring occurring to deform the land surface upwards is mind-blowing, at least for this hydrogeologist (that’s me!). The authors note that this over-pressuring creates dangers for drilling and that deformation, in general, could be replumbing the subsurface and creating more environmental concerns.