ADVERTISEMENT
See Inside Earth 3.0 - Top 10 Myths about Sustainability

The Ogallala Aquifer: Saving a Vital U.S. Water Source

The massive underground water source feeds the middle third of the country but is disappearing fast. Can it be conserved?

Until recently, most of the region had no permanent settlements. Native American tribes who used the open plains for seasonal hunting retreated to river valleys to pitch their tents. When Spanish conquistador Francisco Vazquez de Coronado came through in 1541 looking for the gold cities of Cibola, he marched his iron-clad men to the brink of exhaustion, never knowing that water to quench their near-maddening thirst lay mere yards beneath their boots. Similarly, cattle drives in the 1860s and 1870s collapsed in a perfect storm of drought, overgrazing and falling meat prices. And early attempts at farming were plagued by soil erosion and cycles of drought that culminated in the 1930s Dust Bowl.

Industrial-scale extraction of the aquifer did not begin until after World War II. Diesel-powered pumps replaced windmills, increasing output from a few gallons a minute to hundreds. Over the next 20 years the High Plains turned from brown to green. The number of irrigation wells in West Texas alone exploded from 1,166 in 1937 to more than 66,000 in 1971. By 1977 one of the poorest farming regions in the country had been transformed into one of the wealthiest, raising much of the nation’s agricultural exports and fattening 40 percent of its grain-fed beef.

But the miracle of new pumping technology was taking its toll below the prairie. By 1980 water levels had dropped by an average of nearly 10 feet throughout the region. In the central and southern parts of the High Plains some declines exceeded 100 feet. Concerned public officials turned to the U.S. Geological Survey, which has studied the aquifer since the early 1900s. With their state and local counterparts, USGS officials began monitoring more than 7,000 wells to assess the annual water-­level changes.

What they found was alarming: yearly groundwater withdrawals quintupled between 1949 and 1974. In some places farmers were withdrawing four to six feet a year, while nature was putting back half an inch. In 1975 the overdraft equaled the flow of the Colorado River. Today the Ogallala Aquifer is being depleted at an annual volume equivalent to 18 Colorado Rivers. Although precipitation and river systems are recharging a few parts of the northern aquifer, in most places nature cannot keep up with human demands. “We have optimistic locations. Other places we can see the end,” says David Pope, who administered groundwater regulations in Kansas from 1983 to 2007 as the state’s chief engineer.

Sustainable Solutions
For Funk, the depressing data he took home from that Garden City meeting was transforming. Whereas other farmers responded to declining water levels by adding wells, Funk eliminated them: “We decided to go dryland.” Today he pumps almost no water on his 6,000 acres, which are planted largely in wheat and grain sorghum. These crops are typically not as lucrative as corn, but they are sustaining Funk’s family. To farm without groundwater, Funk has changed some of his methods. Instead of plowing his fields after harvest, he leaves the stubble in the ground and plants a new crop in the residue. This technique not only reduces soil erosion but also decreases evaporation and catches more blowing snow than bare ground. Leaving crop residue in the field can reduce moisture loss by the equivalent of an inch or more of rainfall annually, scientists say. Funk aims to capture every bit of the 18 inches of precipitation that fall on southwestern Kansas. “Got to,” he says. “It’s all we’ve got around here.”

Funk is part of a small but steady movement away from groundwater dependence. The scientific certainty of Ogallala’s decline has spurred an interest in conservation throughout the region. Researchers are developing less thirsty crops, including drought-tolerant corn. Their goal is to reduce the amount of water corn crops require by at least 10 percent, says Wenwei Xu, a research scientist at Texas A&M. The Ogallala Initiative, a U.S. Department of Agriculture project, funds studies designed to make the agricultural industry—and the rural communities that depend on it—more sustainable. An annual $3.6-million congressional appropriation supports the research, ranging from irrigation techniques and precipitation management to animal feedlot operations.

Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American Special Universe

Get the latest Special Collector's edition

Secrets of the Universe: Past, Present, Future

Order Now >

X

Email this Article

X