...The Ogallala aquifer lies under eight states from South Dakota to Texas. If it were above ground, its 174,000-square- mile surface area would be nearly double all five Great Lakes. About one-fifth of all U.S. cattle, corn, cotton, and wheat depend on the Ogallala. Without it, meat prices would rise, farm exports fall, and rural communities wither, says Bill Lapp, a former chief economist for ConAgra Foods and the Omaha-based president of Advanced Economic Solutions, an agriculture consultant.
About 30 percent of the aquifer’s water has already been pumped out of the ground. An additional 39 percent is expected to be gone in the next 50 years. Replenishing it would take millennia. That’s forcing quiet shifts in the region’s agriculture, with farmers in dried-out areas facing restrictions on bank loans and pressure to switch crops.