Why Great Plains agriculture is particularly vulnerable to drought

The American West is experiencing its driest period in human history, a megadrought that threatens health, agriculture and entire ways of life. DRIED UP is examining the dire effects of the drought on the states most affected — as well as the solutions Americans are embracing.

The underground aquifer system that supplies water for a quarter of U.S. food production is in severe and possibly terminal decline.

By the end of the century, production of grain, meat and dairy across the Southern Plains, and especially in Texas, could collapse as rainfall patterns change and temperatures rise, putting ever more pressure on declining reserves of water from below.

But while the drought — and the climate change driving it to its current extremes — is exacerbating a long-running agricultural crisis from the Texas Panhandle to South Dakota, it did not cause the original problem.

Too much underground water from sources such as the Ogallala Aquifer is being used too fast. That water source, the High Plains Aquifer, feeds about a quarter of U.S. crop production, according to the Department of Homeland Security.

And as farmers, climatologists and agricultural economists told The Hill and our investigative partners at Amarillo, Texas, station KAMR, it’s a dilemma that is simple in theory — and nearly unsolvable in practice.

Mining for water

Before the mid-20th century, the High Plains were largely used for cattle, which were spread sparsely over sprawling land where they ate what grass could grow off the area’s occasional rains. 

New forms of irrigation allowed farmers and hydraulic engineers to reach the fossil reserves of groundwater deep beneath the prairie, allowing the cultivation of vast rows of thirsty crops such as corn in a landscape that would not usually support them.

Ninety percent of the water drawn from the Ogallala goes to agriculture, pumped up to feed row crops such as corn and soybeans, or given to cattle to drink.

“It’s inevitable that we are going to run out of water in this region. And we are seeing this more this year than we have with previous droughts,” agronomist Jourdan Bell of West Texas A&M’s Agrilife told The Hill.

Given current rates of usage, the Ogallala as a whole may see a 70 percent decrease in water levels by 2080 — but parts of the High Plains may run out before midcentury, reports KAMR, which is owned by The Hill’s parent company Nexstar Media Group.

Climate change is making things worse

The decline in the Ogallala was inevitable the moment it was tapped in the 1940s, Texas state climatologist John Nielsen-Gammon told The Hill.

The timing of when the Ogallala begins to run out “is going to be affected by climate change, but it’s not something that is going to be avoided no matter what,” he said.

Aquifers depend on water seeping slowly down from the surface to charge, and if they are being drained for irrigation faster than that happens, they will eventually go dry.

“Recharges never kept up with demand and extraction in Texas,” Nielsen-Gammon said. Groundwater reserves are “used like a natural resource that will eventually run out.”

The challenge, he said, is “basically managing that transition” to a fully arid Great Plains.

But human-caused climate change is helping drive the decline in rainfalls, exacerbating the problem. 

A study published in July in the Journal of the American Water Association found that the Ogalalla would decline 50 percent faster in a world where rain amounts fall by 25 percent and the number of days above 96 degrees doubles.

“The increased demand will directly lead to either accelerated depletion of the aquifer or loss of irrigated farmland,” Nielsen-Gammon added.

Texas is in particular trouble

The long-term discrepancy between Great Plains rainfall and its need for water is a conundrum for the entire Ogallala region, particularly for the Texas Panhandle, which sits between 200 and 400 feet above the underground water supplies, separated from it by a thick and largely impermeable layer of clay, Bell of West Texas A&M said.

That’s very different in the Northern Plains, where the aquifer may be just a few feet below the surface and a sandy soil mix allows rainwater to filter back in. 

The regulatory regimes are different too. In South Dakota, farmers can only pump to the level at which the aquifer can recharge. In Kansas, a state program provides farmers with incentives and expertise to help them ratchet down the amount of water they’re pumping from the aquifer.

In Texas, however, groundwater reserves provide a form of almost regulation-free water. Farmers with legal water rights there can draw as much water from underground as their wells can reach and their pumps can handle — regardless of impacts on their neighbors.

This creates a situation sometimes called the “law of the biggest pump,” in which whoever can pump the most water gets the most water, KAMR reported in July. 

But while decline looms, for now water is plentiful for those who can drill for it — and Texas’s lax groundwater regulations have drawn thirsty industries such as dairy from states with more restrictive policies.

Over the last two decades, Bell said, enormous dairies have spread around Amarillo, ushering in a wave of other agro-industries to make products such as cheeses.

Farmers often point to the dairies’ use of water to explain the region’s shortfalls, Bell said. “These are very big dairies,” she said, “I mean 50,000-plus head of cattle.” 

But she emphasized that dairy has also helped reverse some of the long-running regional economic decline, halting the collapse of some small towns and injecting a measure of life and energy back into rural communities. While the industry has “just extended the life here a little longer — nevertheless, you know, it has made things today better in some areas,” she said.

Shortages have already begun

Some small communities have already run out of potable water as their wells can no longer reach the depleting levels of groundwater, and are having it shipped in on trucks, Bell said.

Without groundwater for irrigation, some farmers will shift to hardier but less productive “dryland” systems dependent on rain.

Others will lean on raising cattle, David Anderson of Texas A&M’s Agrilife said, but in many cases it’s growing too dry for that.

Once the land can no longer support cattle, “there’s really no alternative,” Anderson said. “There won’t be any other alternative crops or stock.”

—Updated at 9:51 a.m.

KAMR’s Cat Keenan contributed to this report.

Previously in this series:

Lakes Mead and Powell are at the epicenter of the biggest Western drought in history

Seven stats that explain the West’s epic drought