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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?

At a USDA research station near Amarillo, Tex., scientists are compiling data that encourage Funk and other farmers to use low- or no-till techniques (such as leaving crop residue to decompose), says Nolan Clark, station director and an agricultural engineer. Other projects aim to bring high tech down home. Engineers have installed 16 wireless infrared sensors on the arm of a center-pivot system used to irrigate cotton in a research plot. The sensors are calibrated to measure leaf temperatures, allowing the plants themselves to tell computer-controlled irrigation equipment when they are thirsty. At a scientifically determined threshold, the sprinklers turn on automatically. Because these robotic irrigation systems apply water only when it is needed, in test fields they are saving two inches per crop per season, Clark says.

Evapotranspiration is another way plants can communicate with high-tech irrigation systems. Researchers are designing equipment that uses lasers to measure the turbulence caused by heat waves above crops. The greater the turbulence, the more water plants need. The laser equipment will eventually estimate daily evapotranspiration rates on a regional scale. These will be posted on the Internet, giving farmers information they can use to adjust their irrigation to the needs of their crops.

Such devices may not save dramatic amounts of water, but in West Texas, where the Ogallala is in rapid decline, they are critical. A savings of 10 to 15 percent per crop per season spread over millions of acres—“that’s a significant amount of water,” Clark says. “We may not make the aquifer sustainable, but we may give it another 100 years.”

New Demands
Yet even as these innovations move from experimental plots to production fields, improvements in efficiency may be offset by new demands on groundwater. Bio­fuels are the latest enticement to grow corn, which garners higher profits but requires more water than most other crops. Plans to double the number of ethanol production facilities in the High Plains region are driving farmers to increase corn production despite already scarce groundwater. That could require up to 120 billion additional gallons of Ogallala water annually, according to a report by the Environmental Defense Fund (EDF).

Growing populations throughout the Great Plains region are also demanding more municipal water from the only available source: the aquifer. T. Boone Pickens, the billionaire oilman and recent alternative energy advocate, is among the entrepreneurs who have entered the domestic water market. A Texas law granting landowners unrestricted rights to the water beneath their property makes it possible for Pickens to sell groundwater from his 24,000-acre Mesa Vista Ranch in the Texas panhandle to metropolises as far away as Dallas and El Paso. The 654-mile pipeline he plans to build to El Paso would cost $2.1 billion. But with water sales priced at more than $1,000 an acre-foot, profit is waiting to be had.

Looming over these new demands for the Ogallala’s finite water supply is climate change. Although precipitation in Nebraska at the northern end of the aquifer will likely increase, scientists predict the southern parts of the region will get even less than the 16 inches of annual precipitation they now receive.

In the face of these combined demands on the already overtapped aquifer, many High Plains water users are joining Funk in reassessing their futures. No matter how efficiently they use it, they know the groundwater will eventually be gone—leaving them, their communities, and most of the region high and dry. Like Funk, they are starting to make plans for a time when the Ogallala will not meet their economic needs. Some growers are joining Funk in moving to dryland farming—growing wheat and other crops that do not require irrigation. In eastern Colorado, farmers are planting hardy sunflowers, which require 30 percent less water than corn.

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