The Threat to the Ogallala Aquifer

By: Rachel M. Bauer

The Ogallala Aquifer , also known as the High Plains Aquifer,[1] has been accumulating water in porous rock under eight Midwestern states for 15,000 years.[2]  However, for the past 60 years, the Ogallala has been pumping out water faster than it has been able to replenish, due mostly to the vast amounts of irrigation.[3]  The region above the Ogallala supplies one fifth of the total annual United States agricultural harvest[4] and thirty percent of all water used to irrigate U.S. agriculture comes from this aquifer.[5]

Output from the Ogallala increased dramatically after World War II. Diesel-powered pumps replaced windmills, increasing output from a few gallons a minute to hundreds.[6] The number of irrigation wells in West Texas alone went from 1,166 in 1937, to over 66,000 in 1971.[7] Corn is typically singled out as the main contributor to the aquifer’s depletion because it is so water consumptive.[8] However, “[i]t is dairies and cotton and corn. And alfalfa and millet and beef cattle and lawn sprinklers and every other use that demands a piece of the large but limited Ogallala supply. . . Collectively, they are going to run out, and each of them is going to demand that all of the others have to run out first.” (emphasis original)[9]

Groundwater depletion varies depending on the saturated thickness of the aquifer in that area.[10] Half of the aquifer has less than a hundred feet of saturated thickness,[11] but some areas in Nebraska can reach up to a thousand feet.[12] At least 30 feet of saturated thickness is necessary for large-scale irrigation.[13] 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 have exceeded 100 feet.[14] Today the Ogallala Aquifer is being depleted at an annual volume equivalent to 18 Colorado Rivers.[15]  Once it is depleted, scientists say it can take up to 6,000 years to replenish.[16]

This leads to an interesting dilemma: reducing water consumption or affecting the food markets and the livelihood of the farmers. Some farmers make the switch to dryland—or unirrigated—farming, but that isn’t as profitable.[17] Additionally, one could be faced with the problem of being the one dryland farmer is in the midst of irrigated farmland, where groundwater depletion occurs regardless.[18]

What’s next? Some farmers are selling their farm land for wind turbines since “we can’t water our land anymore anyway.”[19]  Other farmers have taken it upon themselves to set up conservation zones.[20]  Researchers are turning to technology to develop drought-tolerant corn, which would reduce the amount of water corn crops require by at least 10 percent.[21]  Some choose to do nothing and leave the problem to future generations. Whatever decision is made, the Ogallala cannot, and will not, last forever.

[1] Leonard F. Konikow, Groundwater Depletion in the United States (1900-2008), United States Geological Survey 22 (2013), https://pubs.usgs.gov/sir/2013/5079/SIR2013-5079.pdf

[2] Laura Parker, What Happens to the U.S. Midwest When the Water’s Gone?, National Geographic (August 2016), http://www.nationalgeographic.com/magazine/2016/08/vanishing-midwest-ogallala-aquifer-drought/ [hereinafter Parker].

[3] Id.

[4] Jane Braxton Little, The Ogallala Aquifer: Saving a Vital U.S. Water Source, Scientific American (March 2009), https://www.scientificamerican.com/article/the-ogallala-aquifer/ [hereinafter Saving a Vital U.S. Water Source].

[5] Brian Jacobs, et. al., A Vanishing Aquifer, National Geographic (August 2016), http://www.nationalgeographic.com/magazine/2016/08/vanishing-aquifer-interactive-map/ [hereinafter A Vanishing Aquifer].

[6] Saving a Vital U.S. Water Source, supra note 4.

[7] Id.

[8] Parker, supra note 2.

[9] Id.

[10] A Vanishing Aquifer, supra note 5.

[11] Id.

[12] Parker, supra note 2.

[13] A Vanishing Aquifer, supra note 5.

[14] Saving a Vital U.S. Water Source, supra note 4.

[15] Id.

[16] Id.

[17] Parker, supra note 2.

[18] Id.

[19] Id.

[20] A Vanishing Aquifer, supra note 5.

[21] Saving a Vital U.S. Water Source, supra note 4.

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