Less water, fewer farmers: the future of agriculture on the Ogallala Aquifer
It’s harvest season in Yuma, Colorado, which means Ruben Richardson is in the cab of his combine, cutting corn. That’s where you’ll find him from sun-up to sun down for a solid month in mid-autumn because that’s how long it takes a couple of 40-foot combines to get through 5,500 acres, give or take.
Rollers at the leading edge of the combine devour 16 rows at a time, grabbing the tall, dry stalks by the ankle, and yanking them down and into the machinery. Yellow ears of corn are scraped off the stalk and sucked into the belly of the combine for further processing.
The whole operation is loud and dusty. Dirt, plant debris and flimsy kernel jackets fill the air. But inside his cab, Richardson stays cool and clean. He knows he’s lucky to harvest so many acres after a long and dry growing season that left its mark on corn crops across the region.
“The yields are off,” Richardson explained. “We’re a little bit short of water. This soil – you have to water a bunch every day to maintain it.” He had to use a lot more water in his fields than usual this year, just to produce any crop under drought conditions.
That water was delivered by 58 center pivot sprinklers, across Richardson’s fields of irrigated corn and sugar beets.
The sprinklers were fed, in turn, by 45 high-capacity wells pumping groundwater out of the Ogallala Aquifer, far below the ground.
Meet the Ogallala Aquifer
Picture a bathtub. But this bathtub has a very rocky, jagged bottom. When you pour in the water, the tub doesn’t fill evenly. Instead, it forms pools of different sizes within the crags and pits of that rocky floor.
Now imagine that bathtub is huge: 175,000 square miles huge. It stretches across 8 stations, from South Dakota all the way down to Texas, including parts of eastern Colorado.
Also, the whole thing is deep underground.
That is the Ogallala Aquifer. A vast, but uneven reserve of freshwater stored under the earth.
The people who live on top of the aquifer pump it out of the ground. More than 90 percent of Ogallala water is used for agriculture, and that water transformed the high plains dust bowl of eastern Colorado into highly productive farmland.
But according to Meagan Schipanski, an associate professor at Colorado State University and Co-Director of the Ogallala Water Coordinated Agriculture Project, the aquifer has its limits. The water has been over-allocated for decades. The current drought is exacerbating the shortage. “That water is a nonrenewable resource,” Schipanski said, “we're going to use it faster than it can recharge itself.”
The hydrology and terrain of the aquifer is highly variable, making it difficult to generalize about just how much water has been depleted. But across northeastern Colorado, on average the aquifer is down about 30% from where it started before groundwater irrigation became widespread in the mid 20th-century.
That decline hits someharder than others. “It's very heterogeneous. There are deep pockets [of water] and there are shallow pockets,” Schipanski said. “you're going to pump certain valleys faster than other valleys.”
It doesn’t take a hydrologist to understand that the aquifer is declining. Richardson has watched the water table drop in his irrigation wells for years. “We've been dropping a foot a year historically, just kind of average,” he said. “Two years ago, we dropped 2 to 3 feet. Last year, we dropped 2 to 7 feet.”
“It's obvious we've got a problem here,” Richardson said, reflecting on his disappearing groundwater. “We're pumping it out quicker than it's being replenished.”
Writing on the Wall
That disappearing groundwater is essential to Richardson’s operations. The corn he’s harvesting drank aquifer water all season long. The moisture that used to be stored deep under the earth is now stored in millions of bright, golden corn kernels – so many they quickly overflow the bed of the combine, showering down onto the roof of the cab when Richardson taps the brake.
He signals to Isaac, a farmworker hired for the season from Mexico, nearby in the cab of a large grain cart. Isaac drives up alongside the combine, and Richardson opens the floodgates. A thick chute sucks the harvested corn kernels out of the combine and releases them into the bed of the grain cart.
“Five bushels a second is what's coming out of that right now,” Richardson explains.
The two vehicles start up again, advancing together at about 4 miles per hour through the cornfields. A few minutes later, the grain cart is filled to capacity. Isaac peels off to the edge of the field, where he’ll empty into the bed of a waiting semi-truck.
A second grain cart pulls up beside the combine to take Isaac’s place in the choreography of heavy machinery. It’s driven by Riley, Richardson’s 23 year-old son.
Riley came back to Yuma after finishing college last year. He wants to stay here, and take over his father’s farm one day, along with his younger siblings. “I've been driving tractors since I was eight years old. I kind of got tossed into it,” Riley said. “That's all I've ever really known.”
As much as Riley is attached to the land and lifestyle, he’s acutely aware of the looming water crisis, and that worries him. “We're really going to see a major change,” Riley said. “Maybe not in my dad's lifetime, but probably for sure in my lifetime.”
It’s not as if the declining aquifer is an existential threat to Riley’s future or others invested in high plains agriculture. . They believe farmers will always work the land, but Riley is correct. There will be dramatic changes. Many irrigated fields will become dryland farms, meaning crops that don't have any irrigation. That would be a huge hit to profitability and predictability.
Schipanski says a mass transition from irrigated to dryland farming would have a huge financial impact in the plains communities. “To maintain profitability in the dry land scenario versus irrigated requires a larger farm size. And so what we're probably looking at is fewer farmers on the landscape,” Schipanski said. “As water becomes more scarce, that will definitely strain the rural economies.”
Ruben Richardson sees the writing on the wall. He has experience farming dryland fields In addition to their 5,500 acres of irrigated corn, the Richardsons also planted about 1,000 acres on his dryland fields. On average years, with mild temperatures and decent rainfall, dryland corn fields produce significantly less than irrigated fields. Last summer’s drought was not average. “On the dryland, out of 1,000 acres, we ended up picking about 160,” Richardson said. “The rest of it burned up.”
“Dry land is not going to sustain this community,” Richardson said. “Yeah, there'll always be the town here, but it'll be considerably smaller. So you’re talking about, the values of homes going down. You're talking about the hospital tax base. You’re talking about schools.”
Some parts of the eastern plains aren’t even suitable for dryland farming, including some of Richardson’s own land. If the water dries up, those fields will revert back to prairie rangeland. Schipanski and her team estimate 10% to 40% of the land in counties with high rates of groundwater decline would not be suitable for dryland farming. They also estimate that pasture brings in less than one tenth of dryland revenue per acre.
Yuma, where Richardson farms, generally sits on deeper pockets of water than neighboring counties to the south. Most of his wells have several decades of water left in them. But he’s still feeling the impact of groundwater depletion on his properties. He has already had to retire one low-producing well. A second well had to be re-drilled when the water table dropped below the perforation point. Richardson says that’s not uncommon.
He has yet to measure the impact of last summer’s drought on his water levels.
“It's kind of like you've got cancer and how many more days you got to live,” Richardson said. “I mean. It's kind of a morbid thought.”