In a study released Monday, a research team led by David Steward, a professor of civil engineering, predicted the aquifer will be 69 percent depleted by 2060 at current rates of use. Replacing the water in the aquifer would take from 500 to 1,300 years, Steward said.
The aquifer, part of the High Plains Aquifer System, underlies parts of Texas, New Mexico, Oklahoma, Kansas, Colorado, Wyoming, Nebraska and South Dakota, taking its name from the town of Ogallala, Neb. More than one-quarter of the irrigated farmland in the United States gets its water from the Ogallala.
In 1960, the aquifer was only 3 percent depleted. That has increased to 30 percent.
Steward predicts farmers will continue to become more efficient in their use of water, helped by crops bred or genetically designed to use less. He expects water use to peak in 2025 and crop yields to increase until about 2040.
After that, he said, depletion of the aquifer will depend on what choices are made.
"The main idea is that if we're able to save water today, it will result in a substantial increase in the number of years that we will have irrigated agriculture in Kansas," Steward said. "We'll be able to get more crop in the future and more total crop production from each unit of water because those efficiencies are projected to increase in the future."
"Tapping unsustainable groundwater stores for agricultural production in the High Plains Aquifer of Kansas, projections to 2110" was published in Proceedings of the National Academy of Sciences of the United States of America.
"We really wrote the paper for the family farmer who wants to pass his land on to his grandchildren knowing that they will have the same opportunities that farmers do today," Steward said. "As a society, we have an opportunity to make some important decisions that will have consequences for future generations, who may or may not be limited by those decisions."