High Plains Aquifer will be 69 percent depleted in 50 years, K-State study says

If Kansas farmers keep irrigating crops at current levels, an estimated 69 percent of the water in the High Plains Aquifer will depleted within 50 years, according to a study released Monday.

Although the High Plains Aquifer supplies 30 percent of the nation’s irrigated groundwater and extends beneath parts of eight states in the Great Plains, this latest study focused on the Ogallala aquifer, which also covers several states, including Kansas, Nebraska and Oklahoma. The report by researchers at Kansas State University was published in the scientific journal “Proceedings of the National Academy of Sciences of the United States of America.”

The report noted that only 3 percent of its water had been tapped in 1960 – before farmers began putting in huge irrigation systems in western Kansas. An estimated 30 percent of the aquifer had been depleted by 2010, the study said, forecasting an additional 39 percent of the aquifer’s water will be gone by 2060.

“Society has an opportunity now to make changes with tremendous implications for future sustainability and livability,” the study concluded. “The time to act will soon be past.”

Irrigators are pumping more water than is naturally recharging. The aquifer’s natural recharge accounts for just 15 percent of the amount of water now being pumped out of it.

Once the water in the aquifer is gone, the study projects it will take between 500 and 1,300 years to refill. But it also outlined several scenarios whereby irrigators could cut back on pumping and possibly extend its usable life to 2110.

David Steward, a K-State professor of civil engineering and co-author of the study, said researchers put forth those scenarios not to advocate any particular policy but to give people an understanding of what the implications could be for the present and the future of corn and cattle production in the region. The Ogallala aquifer supports nearly one-fifth of the wheat, corn, cotton and cattle produced in the U.S., according to the U.S. Department of Agriculture.

“The motivation for the study … was the family farmer who wants to be able to pass his or her land on to their grandchildren and have their grandchildren have the same capacity, the same abilities for successful agriculture that they do,” Steward said.

West-central Kansas has had the biggest depletion to date, but the largest water stores in southwest and northwest Kansas are forecast to have pumping capacity limitations within 20 years given current trends, researchers wrote.

Both Steward and Jim Butler, chief of the geohydrology section of the Kansas Geological Survey, lauded a promising pilot program enacted earlier this year in northwest Kansas’ Sheridan County aimed at prolonging the life of the aquifer. The Northwest Kansas Groundwater Management District No. 4 instituted a mandatory water management program that limited pumping for the next five years. Irrigators who pump more face fines and a suspension of their water use for two years.