The chief underground water source for irrigating the agriculture-rich Texas High Plains is depleting at a pace that some fear will exhaust it far more quickly than anticipated.
Records examined by the Lubbock Avalanche-Journal show the Ogallala Aquifer has dropped about 325 billion gallons every year for at least the past four decades, meaning the 40-foot decline in the water supply amounts to about a foot each year. But at least two Texas counties west of Lubbock — Parmer and Castro — have plunged more than double that amount — 100 feet.
The aquifer covers parts of eight states from the Dakotas to Texas, holds almost 3 billion acre-feet of water and could run out in 50 years, according to a Kansas study last year. An acre-foot of water is the equivalent of 1 acre of surface area covered by water 1 foot deep — 325,853 gallons.
"When anybody tells me it's going to last for 50 years, I just laugh," Lucia Barbato, associate director at the Center for Geospatial Technology at Texas Tech University, told the newspaper in a story published Sunday.
"How long the aquifer lasts depends on where you are."
The Texas Tech center estimates four counties have less than 15 years before groundwater is exhausted for irrigation.
"Certainly, the magnitude of the decline is greatest in Texas," said Virginia "Ginny" McGuire, a hydrologist with the U.S. Geological Survey in Nebraska. "You're still using water at a much faster rate than it's being recharged."
"You see most of the decline where the irrigated agriculture is," Barbato said. "It's obvious that irrigated agriculture is not sustainable."
Farmers aren't oblivious to the situation. Some even have turned off their wells.
"You just have to learn to do with less," said Barry Evans, 52, who rotates cotton, wheat and grain sorghum on 3,000 acres in Swisher County.
Roughly two-thirds of his crop if now dryland farming, meaning it relies on rainwater, not irrigation.
"I can see in the pretty near future, I won't be irrigating at all," Evans said. "We'll adapt, and farm this country somehow."