The Final Hour: The Ogallala Aquifer Is Drying Up Which Means The Great Plains Could Soon Turn Into The Great American Desert

America's breadbasket is facing an environmental crisis of unimaginable proportions and most Americans have absolutely no idea what is happening. The water that is used to irrigate much of America's Great Plains comes from a massive underground lake known as the Ogallala Aquifer. This gigantic underground lake stretches from southern South Dakota through northern Texas, covering approximately 174,000 square miles. So what is the problem? Well, it turns out that the Ogallala Aquifer is being drained at an alarming rate, and that means that the Great Plains could soon turn into the Great American Desert. If that happens, American could very well see a devastating repeat of the Dust Bowl days of the 1930s.

One of the scientists trying to get out the warning about this coming environmental nightmare is Dr. Kevin Mulligan, a professor of Economics and Geography at Texas Tech. Dr. Mulligan and his students have mapped the Ogallala Aquifer extensively, and what they have found is quite alarming. Not only have they found that the aquifer is much shallower in places than many originally thought, but they also have found that the aquifer is being drained much faster than anticipated.

If the Ogallala aquifer dries up, the Great Plains could become a vast desert, with a repeat of the droughts that led up to the Dust Bowl of the 1930’s. After the Dust Bowl, industrialized agriculture took off and began withdrawing water from the aquifer at a faster rate that it was being replenished naturally. Once it goes dry, it will take thousands of years to refill, so conservation is key in maintaining this most important of natural resources.

The Final Hour: The Ogallala Aquifer Is Drying Up Which Means The Great Plains Could Soon Turn Into The Great American Desert

The Ogallala is an unconfined aquifer, and virtually all recharge comes from rainwater and snowmelt. As the High Plains has a semiarid climate, recharge is minimal. Recharge varies by amount of precipitation, soil type, and vegetational cover and averages less than 25 millimeters (1 inch) annually for the region as a whole. In a few areas, recharge from surface water diversions has occurred. Groundwater does flow through the High Plains Aquifer, but at an average rate of only 300 millimeters (12 inches) per day.

The depth to the water table of the Ogallala Aquifer varies from actual surface discharge to over 150 meters (500 feet). Generally, the aquifer is found from 15 to 90 meters (50 to 300 feet) below the land surface. The saturated thickness also varies greatly. Although the average saturated thickness is about 60 meters (200 feet), it exceeds 300 meters (1,000 feet) in west-central Nebraska and is only one-tenth that in much of western Texas. Because both the saturated thickness and the areal extent of the Ogallala Aquifer is greater in Nebraska, the state accounts for two-thirds of the volume of Ogallala groundwater, followed by Texas and Kansas, each with about 10 percent.

Increased efficiency in irrigation continues to slow the rate of waterlevel decline. State governments and local water districts throughout the region have developed policies to promote groundwater conservation and slow or eliminate the expansion of irrigation. Generally, management has emphasized planned and orderly depletion, not sustainable yield. Depletion results in reduced irrigation in areas with limited saturated thickness and increased energy cost in all areas as the depth to water increases.

Center-pivot sprinklers are among the irrigation methods used in the High Plains. Large quantities of groundwater pumped from the Ogallala Aquifer allows these semiarid western lands to yield abundant harvests.

The average specific yield for the High Plains Aquifer is about 0.15. This means that only 15 percent of all the water available in the aquifer can be recovered using irrigation pumps, while the rest remains unused and locked up in the unsaturated zone . Groundwater depletion problems could be forestalled if this presently nonrecoverable water could be forced to the saturated zone . One experimental means of accomplishing this is by injecting air into the unsaturated zone, which breaks down capillary action and permits the movement of water down to the saturated zone. Air injection experiments have shown positive results for very localized areas. However, the widespread applicability of this technology has not yet proven effective.

Water Encyclopedia

These formations are large enough to see from satellite photos, giving you a better idea how widespread this practice is, and how close we are to running the well dry.