The Swamp Stomp

Volume 16, Issue 19

The Ogallala Aquifer is one of the world’s largest shallow water table aquifers, located in portions of 8 states in the Great Plains and covering an area of 174,000 square miles.  Is this vast underground reservoir, which is used to irrigate the farmlands in the Great Plains,disappearing?  Like many other natural resources, the Ogallala Aquifer is finite—but it has not been utilized with the reality of the aquifer’s exhaustibility in mind.  In fact, for many years, the High Plains farmers who pumped the Ogallala to water their crops were entirely unaware that the water below them would not last forever.  These farmers, who provide around one-fifth of the total U.S. agricultural harvest and $20 billion worth of food and fiber, rely heavily on the Ogallala.  Some estimates show that 30% of the Ogallala’s water has already been used. Within the next 50 years, another 39% is expected to be depleted.  And scientists estimate that it would take 6,000 years to replenish the Ogallala naturally.  Factor in that many of these states receive only about 20 inches (or less) of rainfall annually, and it becomes very clear that the disappearance of the Ogallala Aquifer would devastate this farming region of the United States and those who are supplied with food by these Great Plains farms.

What can be done to improve sustainability?  Already, some farmers are switching from corn—the main crop grown in the region—to crops like wheat, sunflowers, and grain sorghum, because they require far less water than corn.  Some farmers are abandoning farming altogether and turning their land from crops back into natural grasslands, which cattle could graze. Leaving crop residue, instead of plowing fields after harvest, can reduce soil erosion and decreases soil evaporation.  This technique, which farmers across the Great Plains are using, can reduce moisture loss by one inch annually.  In response to this looming water crisis, research is being done to develop corn that requires less water and can survive droughts better. Engineers are also working on developing infrared sensors that can detect leaf temperatures and determine when crops need to be watered, so that farmers don’t waste water on crops that don’t need it.  Experimentation suggests that these sensors could save farmers two inches of water every crop season. The Natural Resources Conservation Service (NRCS), a branch of the Department of Agriculture, has recently invested $8 million in conservation of the Ogallala with the Ogallala Aquifer Initiative. The initiative has taken on projects such as building soil health by using cover crops and no-till, improving the efficiency of irrigation systems, and education on water conservation.  Still, these measures will only lengthen the time that farmers can pump the aquifer.  Because of its slow replenishment rate, pumping water from the Ogallala will likely never be truly sustainable.

Furthermore, the increase in demand for corn may negate any improvements in conservation.  The growing bio-fuel market, especially the plan to double the number of ethanol production facilities in the region, has created a great incentive for many farmers to continue, or even ramp up, corn production.  Because corn requires so much water—350,000 gallons per acre, over a 100-day growing period—the Environmental Defense Fund has estimated that the increase in corn production could require up to 120 billion additional gallons of water from the Ogallala Aquifer.  The Aquifer also provides municipal water to growing populations throughout the Great Plains region and many landowners, under a Texas law that grants unrestricted use of water under personal property, are piping groundwater from the aquifer to cities and towns.  On top of all of this, scientists predict that in coming years, the southern part of the region will receive even less annual precipitation.

While efforts will continue to be made to conserve the water in the Ogallala, many residents and farmers of the Great Plains are being forced to come to terms with the limitations of the aquifer.  Many are hopeful that the combination of government incentives, technological advances, and individual efforts to conserve water will extend the life of the aquifer, but as of now, it seems clear that the Ogallala has a limited lifespan.  For now, the Ogallala will continue to serve the Great Plains region as its major water source.