Water levels in the High Plains Aquifer, also known as the Ogallala Aquifer, fell at a faster rate in recent years as widespread drought increased demand on the underground reservoir.
The aquifer lost enough water over a recent two-year period to cover the entire state of Iowa in a foot of water, according to a new report by the U.S. Geological Survey that studies water level changes from 2011-13.
The vast underground lake that supplies water to wells in some of the country’s most productive agricultural land – including parts of Nebraska, Kansas, Colorado, Oklahoma and Texas – lost 36 million acre-feet of water from 2011-13. The aquifer has lost about 8 percent of its stored water since 1950.
Prolonged drought is mostly to blame for the recent depletion, said USGS’ Virginia McGuire.
“If you were a farmer in this area you would have known about the 2012 drought and you would have known about increased pumping in that timeframe,” McGuire said.
In parts of western Kansas and northern Texas, the aquifer is no longer a reliable or sustainable source for irrigation, which has forced some farmers to change how they use their land.
“They’ve had to make some adjustments in farmers going to dry land farming or maybe changing crop types,” McGuire said. “They’ve definitely had to adjust to the declining water levels.”
Irrigation is meant to supplement rainfall, but many arid parts of the Plains states haven’t received typical rainfall in recent years. Without irrigation, farmers may have to cut back on growing lucrative crops like corn and soybeans, in favor of crops like winter wheat and beans, which can require less water.