In the face of escalating water scarcity and climate-driven extremes, a new study offers a roadmap for harnessing floodwaters to replenish depleted aquifers, with significant implications for industries, particularly energy, that rely on steady water supplies. Led by John Malito of the Bureau of Economic Geology at the University of Texas at Austin, the research, published in the journal ‘Environmental Research Letters’ (translated as ‘Letters on Environmental Research’), quantifies the availability of high-magnitude flows (HMFs) for managed aquifer recharge (MAR) in Texas, accounting for legal and environmental constraints.
Texas, with its climate-driven water stress and rising demand, serves as a critical case study. Malito and his team analyzed data from 190 streamflow monitoring gages across the state’s 23 river basins, focusing on flows at or above the 95th percentile—events that typically occur once every two years or less. They found that these HMFs accounted for 31% of total flows, with 52% of those flows unappropriated, meaning they are not reserved for existing water rights holders. This translates to an average of 81 million cubic meters (about 66,000 acre-feet) of potentially available water annually for MAR.
However, the study reveals that the availability of these flows varies dramatically across the state. “We saw a hundredfold increase in unappropriated HMF volumes from semi-arid West Texas to humid southeast Texas,” Malito explains. “This variability is driven by differences in climate and watershed size, but also by legal and environmental constraints.”
One key constraint is coastal inflow requirements, which limit the amount of water that can be diverted for MAR in basins like the Colorado River. “In some cases, environmental and legal constraints significantly reduce the volume of HMFs that can be permitted for MAR,” Malito notes. “This is particularly true in areas with high urban demand and stringent environmental flow requirements.”
For the energy sector, which relies heavily on water for processes like cooling and hydraulic fracturing, these findings could inform long-term water management strategies. By identifying the spatial and temporal availability of HMFs, energy companies can better plan for water storage and reuse, reducing their vulnerability to droughts and regulatory constraints.
The study also highlights the importance of considering both legal and environmental factors when assessing water availability. “It’s not just about how much water is there; it’s about how much can be legally and sustainably used,” Malito says. This nuanced approach could shape future water management policies, ensuring that MAR projects are both viable and environmentally responsible.
As climate change continues to exacerbate water scarcity, the insights from this research could be applied to other regions, particularly in the western U.S., to develop resilient water management strategies. By integrating scientific, legal, and environmental perspectives, Malito’s work offers a template for addressing one of the most pressing challenges of our time: ensuring a sustainable water supply in the face of climate extremes.