The great watering hole beneath the Great Plains is going dry
There are two documentary images of the Great Plains. The first is a black-and-white photograph of the '30s Dust Bowl, with windblown homesteaders treading the cracked earth. The second: a glossy color shot of the same land 40 years later, showing the lush checkerboard farms of America's breadbasket. Now, as if through a strange reversal in time, the second image threatens to fade into the first. For in another 40 years, the territory could backslide into dust and despair. The Ogallala Aquifer, the vast underground reservoir of water that transformed much of the Great Plains into one of the richest agricultural areas in the world, is being sucked dry.
The aquifer is a California-size deposit of water-laden sand, silt and gravel. It ranges in thickness from 1,000 ft. in Nebraska, where two-thirds of its waters lie, to a few inches in parts of Texas. Although it was first tapped in the 1930s, it has been extensively exploited only since the development of high-capacity pumps after World War II. The Ogallala's estimated quadrillion gallons of water, the equivalent of Lake Huron, have irrigated farms in South Dakota, Nebraska, Wyoming, Kansas, Colorado, Oklahoma, Texas and New Mexico, changing a region of subsistence farming into a $15 billion-a-year agricultural center.
For the past three decades, farmers have pumped water out of the Ogallala as if it were inexhaustible. Nowadays they disperse it prodigally through huge center-pivot irrigation sprinklers, which moisten circular swaths a quarter-mile in diameter. The annual overdraft (the amount of water not replenished) is nearly equal to the yearly flow of the Colorado River. Like all aquifers, the Ogallala depends on rain water for recharging, and only a trickle of the annual local rainfall ever reaches it. Gradually built up over millions of years, the aquifer is being drained in a fraction of that time. The question is no longer if the Ogallala will run dry, but when.
W.B. Criswell has been raising cotton on his 1,700-acre farm in Idalou, Texas, since 1955. Cotton is called the camel of crops because it requires little water, yet Criswell is now in trouble. His water table has dropped 100 ft. since he started farming. Nine years ago, he paid $4 an acre to water his cotton; today he pays more than $45. "It's like a disease," he says. "You just accept it and go on." Gerald Wiechman farms 6,000 acres and feeds 2,500 head of steer near Scott City in western Kansas. When his farm's first well started pumping, it tapped water at 54 ft. Today he has to go 130 ft. "I've got another 20 years, maybe," he reckons. On the High Plains of eastern Colorado, the water level has dropped as much as 40 ft. since the 1960s. In parts of Oklahoma, it has dipped that much in four years. Texas, the thirstiest of the eight states, has consumed 23% of its Ogallala reserves since World War II.