The Dry Future of the American Plains: Threats to the Ogallala Aquifer

Project Description

The Great American Plains have been an agricultural powerhouse for decades. In 30 years, they might not be.

The reason? No water.

We don’t often stop to ask where our tap water comes from, let alone where the water that grew our breakfast cereal comes from. For many Americans, the answer is the Ogallala Aquifer, an underground network of freshwater underlying 174,000 square miles in eight U.S. states: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming [1]. While we may take our free-flowing water for granted, American groundwater is far more threatened than we realize.

The Ogallala Aquifer has been drying up since the first high-capacity irrigation well tapped into it in 1909 [2]. Drainage ramped up after World War II [3], when industrial-scale extraction began to fuel an agricultural system that could match the growing population of Baby Boomers.

Since erosion cut off the eastward streams from the Rocky Mountains that filled the Ogallala more than ten million years ago [1], the aquifer hasn’t been connected to any bodies of freshwater. This means that the Ogallala only recharges with rainwater and snowmelt [1]. However, rain doesn’t happen often in a semiarid climate like that of the American West.

Each year, the Ogallala recharges by one inch on average [1]. If fully drained, models estimate that the aquifer would take 6000 years to refill naturally [4]. To make matters worse, climate change models show decreasing precipitation and increasing drought in southern and western regions, meaning that refill might occur even more slowly – all while people and animals are drinking more water to fight the heat [3][5][6].

Today, the Ogallala is pumped to irrigate 13.6 million acres of American farmland [1]. The aquifer supports one-fifth of the U.S.’s major crops, including wheat, corn, cattle, and cotton [1], amounting to a whopping $35 billion per year [7].

The scale of the aquifer is hard to comprehend. According to Scientific American, the Ogallala Aquifer contains enough water to cover the entire continental U.S. with 1.5 feet of water [3]. But the Texas State Water Plan predicts that the Ogallala’s water levels will decline by a staggering 52% before 2060 [10], and 30% of Kansas’s access points have already run dry [7].

So how have we drained it so much?

According to groundwater sustainability researcher Dr. Robert Mace of the University of Texas at Austin, the reasons can be boiled down to “economics, legal inertia, politics, and hydrogeology.” He explains, “The impacts of unsustainable pumping take decades to centuries to be felt, luring users into complacency.” [12]

The Ogallala is part of the High Plains Aquifer System, which provides water for homes, industries, and agriculture in eight states. Ogallala water is of incredibly high quality, generally needing no filtration or treatment before domestic and agricultural use [1]. From 1900 to 2008, we drained a massive 89 trillion gallons of water from the aquifer [7], 94% of which went to farming [1].

Much of this water used for farming is actually wasted; flood or furrow irrigation, the most widely used irrigation technique involving running water through small trenches in crop fields [9], loses about 50% of its water to evaporation and runoff [8]. According to the USGS, 23,000 acres of cropland were irrigated with flood techniques in 2015, using about 43.3 billion gallons of water per day — and wasting half of that [9].

Despite its known wastefulness, western farming still relies heavily on flooding irrigation because of its low cost. Government subsidies encourage farmers to purchase more land to produce more crops, requiring larger irrigation equipment — all of which costs money. To try to break even, farmers are forced to turn to fast and reliable irrigation techniques. This cycle is running the aquifer dry.

Dr. Seth B. Darling, Director of the Advanced Materials for Energy-Water-Systems Research Center at Argonne National Laboratory, explains, “With groundwater, there is obvious short-term gain to be had by pumping lots of it for productive use now. That action will just as obviously result in massive long-term consequences, some of which rise to the level of being potential existential threats, but we do it anyway.” [13]

With a slowly replenishing aquifer, there are no natural ways to speed up the refill process; instead of solutions, we’re left needing to manage the remaining water as best we can.

Scientists, policymakers, engineers, and farmers around the country have proposed a multitude of ideas ranging from subsidizing less water-intensive crops (like wheat and sorghum) [3][8] to injecting air underground to mobilize currently unavailable groundwater [1]. Some of the more attainable solutions include limiting the expansion of irrigated cropland and reducing the cost of water-efficient equipment [7].

Another management strategy involves planting new crops on low- or no-till ground. Not tilling the soil from old crops can reduce soil erosion and water loss from evaporation, as well as catch drifting snow and boost soil nutrients [3].

Economically, farmers can use lowering groundwater levels as a tax write off on equipment. Replacing tax write offs with tax credits for conserving groundwater could be a compelling incentive to monitor and save more water [7].

Modern science is also turning its attention to the groundwater issue. In the laboratories, some scientists are genetically engineering crops like corn to require less water [6]. In the tech world, scientists have developed wireless infrared sensors to sense leaf temperature, providing farmers with indicators of exactly how much water their crops need [3]. Additionally, a new field known as precision agriculture technology has created remote probes that measure soil moisture in real time, showing farmers areas of under- and over-watering [8].

So how do we know which management tactics are best?

Dr. Darling notes, “As with many large-scale, complex challenges, there isn’t really a panacea solution here. Rather, a collection of incremental solutions can come together to get us to a sustainable place.” [13]

The next few years will be crucial for determining the lifespan of the Ogallala Aquifer. Adopting as many management strategies and farming technologies as we can, as well as pressuring local governments and federal agricultural programs to favor conservation, will be key to slowing drainage of the Ogallala’s remaining groundwater. For many of us, understanding the fragility — and necessity — of our nation’s water sources is the first step towards more sustainable daily water use.

Warns Dr. Mace, “In the end, an aquifer can only produce what it can produce. That means, at some point, the Ogallala will be managed sustainably whether we like it or not.” [12]

Reference

[1] Kromm, David E. “Ogallala Aquifer.” Water Encyclopedia. Accessed February 8, 2022. http://www.waterencyclopedia.com/Oc-Po/Ogallala-Aquifer.html.

[2] “Ogallala Timeline.” Ogallala Water. National Institute of Food and Agriculture, United States Department of Agriculture, 2017. https://ogallalawater.org/ogallala-timeline/.

[3] Braxton Little, Jane. “The Ogallala Aquifer: Saving a Vital U.S. Water Source.” Scientific American. Scientific American, March 1, 2009. https://www.scientificamerican.com/article/the-ogallala-aquifer/.

[4] Dobrowolski, James P. “NIFA Impacts: Saving the Ogallala Aquifer, Supporting Farmers.” USDA. United States Government, July 29, 2021. https://www.usda.gov/media/blog/2020/05/01/nifa-impacts-saving-ogallala-aquifer-supporting-farmers.

[5] Parker, Laura. “What Happens to the U.S. Midwest When the Water’s Gone?” National Geographic. National Geographic, August 2016. https://www.nationalgeographic.com/magazine/article/vanishing-midwest-ogallala-aquifer-drought.

[6] Scott, Michon. “National Climate Assessment: Great Plains’ Ogallala Aquifer Drying Out.” Climate.gov. National Oceanic and Atmospheric Administration, February 19, 2019. https://www.climate.gov/news-features/featured-images/national-climate-assessment-great-plains%E2%80%99-ogallala-aquifer-drying-out.

[7] Sanderson, Matthew R, Burke Griggs, and Jacob A Miller-Klugesherz. “Farmers Are Depleting the Ogallala Aquifer Because the Government Pays Them to Do It.” The Conversation, November 9, 2020. https://theconversation.com/farmers-are-depleting-the-ogallala-aquifer-because-the-government-pays-them-to-do-it-145501.

[8] Condos, David. “Farmers Trying to Save the Ogallala Aquifer Seeing Success.” US News. Associated Press, May 7, 2021. https://www.usnews.com/news/best-states/kansas/articles/2021-05-07/farmers-trying-to-save-the-ogallala-aquifer-seeing-success.

[9] Water Science School. “Irrigation Methods: Furrow or Flood Irrigation.” U.S. Geological Survey. United States Government, June 13, 2018. https://www.usgs.gov/special-topics/water-science-school/science/irrigation-methods-furrow-or-flood-irrigation.

[10] Galbraith, Kate. “Panhandling for Water.” The Texas Tribune. The Texas Tribune, June 17, 2010. https://www.texastribune.org/2010/06/17/how-bad-is-the-ogallala-aquifers-decline-in-texas/.

[11] Ruiz, Michael. Kansas Sprinkler Irrigation System. May 19, 2009. Flickr. https://www.flickr.com/photos/simax/3548017782/in/photolist-eZ9mSM-qpt1wR-6pww5o-r2VLdK-rmadcQ-rmabHY-9HGvnV-r4FRvh-r4ELQA-9HL9VQ-r4N4dH-rmfieM-rm7StV-rm9ZZo-qpfE5U-j58Zzx-riXpgy-r4N23R-qpt95g-qpsVWt-riXb2Y-rm7NaK-rm9XLf-riXnJq-rma39d-qpsXXH-j5def1-dkvPL8-aq7HWJ-9KAsjk-aq7Hs3-2i3wjyE-LncGKG-j58Wpe-bdUh4k-j58XoZ-LnodJi-dLEXGL-iXZLp-dLEX6u-dLEXXU-dLEYh5-dLzrjg-dRKP6y-dLEYym-bdUeJM-bdUdAx-bdUcrV-bdUd3K-bdUbP4/.

[12] Private communication with Dr. Robert Mace. February 11, 2022.

[13] Private communication with Dr. Seth B. Darling. February 10, 2022.