Key High Plains aquifer mostly gone in 50 years, study says

FILE: Nov. 26, 2012: A sprinkler is in use near Dodge City, Kansas. (Reuters)

WICHITA, Kan. – If Kansas farmers keep irrigating crops at present 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 that lies underneath Kansas. 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," or PNAS.

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 R. Steward, a Kansas State University 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 motivation for the study —what we really wrote the paper for — 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 depletions to date, but largest water stores in southwest and northwest Kansas are forecast to have pumping capacity limitations within 20 years, given current trends, researchers wrote.

Jim Butler, chief of the geohydrology section of the Kansas Geological Survey, said he had not seen the 4-year study, which was funded by the National Science Foundation, the U.S. Department of Agriculture and Kansas State University's Rural Transportation Institute. But Butler said the findings were consistent in a general sense with past work his agency has done.

"Those clearly show business as usual is going to have a very significant impact on the aquifer," Butler said.

Both Steward and Butler 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 a suspension of their water use for two years and fines.

Ray Luhman, the district's assistant manager in Colby, said the agency is now looking to begin the process this autumn in Sherman County, another high-priority area.

"Everybody can say, 'Hey, we are running out of water, the aquifer is going dry,'" Butler said. "But it is another thing to actually try to do something about it."