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?



NASA

In Brief

  • If spread across the U.S. the aquifer would cover all 50 states with 1.5 feet of water
  • If drained, it would take more than 6,000 years to refill naturally
  • More than 90 percent of the water pumped is used to irrigate crops
  • $20 billion a year in foodand fiber depend on the aquifer

On America’s high plains, crops in early summer stretch to the horizon: field after verdant field of corn, sorghum, soybeans, wheat and cotton. Framed by immense skies now blue, now scarlet-streaked, this 800-mile expanse of agriculture looks like it could go on forever.

It can’t.

The Ogallala Aquifer, the vast underground reservoir that gives life to these fields, is disappearing. In some places, the groundwater is already gone. This is the breadbasket of America—the region that supplies at least one fifth of the total annual U.S. agricultural harvest. If the aquifer goes dry, more than $20 billion worth of food and fiber will vanish from the world’s markets. And scientists say it will take natural processes 6,000 years to refill the reservoir.

The challenge of the Ogallala is how to manage human demands on the layer of water that sprawls underneath parts of eight states from South Dakota to Texas. As landowners strive to conserve what’s left, they face a tug-of-war between economic growth and declining natural resources. What is happening here—the problems and solutions—is a bellwether for the rest of the planet.

High Plains farmers were blissfully unaware a generation ago that a dilemma was already unfolding. In the early 1950s, when Rodger Funk started farming near Garden City, Kan., everyone believed the water was inexhaustible. “People were drilling wells,” he says. “You could pump all the water you wanted to pump.”

And they did. What changed everything for Funk, now age 81, was a public meeting in the late 1960s at Garden City Community College. State and federal geologists, who had been studying where all that water was coming from, announced grim findings. “They said it’s geologic water. When it’s gone, it’s gone,” Funk says. “I remember coming home and feeling so depressed.”

Today his community in southern Kansas, 180 miles west of Wichita, is one of the High Plains areas hardest hit by the aquifer’s decline. Groundwater level has dropped 150 feet or more, forcing many farmers to abandon their wells. The cause is obvious, says Mark Rude, executive director of the Southwest Kansas Groundwater Management District: overuse.

With a liquid treasure below their feet and a global market eager for their products, farmers here and across the region have made a Faustian bargain—giving up long-term conservation for short-term gain. To capitalize on economic opportunities, landowners are knowingly “mining” a finite resource.

Choosing to use water from one of the world’s largest aquifers rather than leaving it in the ground is not irrespon­sible, says Andrew Stone, executive di­rector of the American Groundwater Trust in Concord, N.H. Like coal or natural gas, groundwater is a valuable resource. “There is no benefit to mankind to keeping it unused in cold storage,” Stone says. The challenge is to stretch the life of the aquifer to benefit future generations of farmers and those who depend on their products.

In Garden City, however, the severity of their circumstances is already forcing farmers to take action. They are grappling with how to maintain successful agricultural operations while relying on less and less water, an issue that water users throughout the region, and the world, must eventually face, Rude says. “The community of water users needs to figure this out,” he adds. “We’ll get to sustainability one way or another, but it may be sustaining an economy without the Ogallala Aquifer.”

Tapping the Aquifer
On a hydrographic map, the Ogallala is a Rorschach inkblot that some describe as the shape of a mushroom, others the South American continent. Millions of years ago, when the southern Rocky Mountains were still spewing lava, rivers and streams cut channels that carried stony pieces of the mountains eastward. Sediment eventually covered the area and filled in the ancient channels, creating vast plains. The water that permeates the buried gravel is mostly from the vanished rivers. It has been down there for at least three million years, percolating slowly in a saturated gravel bed that varies from more than 1,000 feet thick in the North to a few feet in the Southwest.

Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American Back To School

Back to School Sale!

12 Digital Issues + 4 Years of Archive Access just $19.99

Order Now >

X

Email this Article



This function is currently unavailable

X