What is causing Texas’ water shortage? Study reveals factors beyond irrigation, population
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It’s no secret groundwater levels have declined across the state over the past eight decades, and that the primary reason was the onset of irrigation in agriculture combined with population growth. But a recent Texas A&M AgriLife Research study has identified other factors having an impact.
The groundwater declines have been most severe in the past four decades. But the news isn’t all bad, according to Srinivasulu Ale, a geospatial hydrology assistant professor in Vernon.
The state’s population is expected to double by 2060, increasing the demand for water at a time when the existing water supply is expected to drop by about 10 percent.
“We wanted to know which areas are more vulnerable to water shortages,” he said.
Previous hydrologic studies on Texas groundwater levels were conducted mostly on an aquifer-specific basis, and lacked the statewide panoramic view Ale and research association Sriroop Chaudhuri wanted to present.
“We know irrigated agriculture is the major cause of depletion in the Texas Panhandle, as compared to increasing urbanization in (North Central Texas),” Chaudhuri said. “We saw a significant drop in median groundwater levels in irrigation wells from 75 to 180 feet between the 1940s and 1950s in the Texas Panhandle, coinciding with the initiation of widespread irrigated agricultural practices.”
But he said they knew there was more to the decline than just these uses, because “unused” wells monitored across the state throughout the decades were also showing varying levels of decline. That was when they studied groundwater and surface-water use patterns, soil characteristics, geology and land cover types to better understand the water-level changes in Texas.
For instance, the South Plains and Panhandle were equally involved in agriculture and irrigated crops over the Ogallala Aquifer. However, the sandier soils of the South Plains allow more infiltration and recharge than the tighter clay soils of the Panhandle.
There is a brighter note, Ale said.
“Interestingly, the trends we observed over the decades show the water-level declines are leveling off recently in some parts of the stat, suggesting a recovery from historical drawdown due to implementation of conservation and regulatory strategies,” Ale said.