The Ogallala aquifer stretches from South Dakota all the way south to Texas and is the largest aquifer in the United States holding as much water as Lake Huron at 2.9 billion acre feet. The Ogallala single handedly turned the arid High Plains region of the midwest into a $20 billion a year agricultural powerhouse that produces one-fifth of the country's wheat, corn and beef cattle. The problem is that the water in the Ogallala, like many aquifers in the world, is being pumped dry. In many places the aquifer is dropping a foot a year and in other places it has already run dry.
According to a note published in the National Geographic:
For the past 60 years, the Ogallala has been pumped out faster than raindrops and snow melt can seep back into the ground to replenish it, thanks largely to irrigation machinery like the one sleeping nearby. As a result, in parts of western Kansas, the aquifer has declined by more than 60 percent during that period. In some parts, it is already exhausted. The decline is steady now, dry years or wet. In 2015 rain was exceptionally heavy—50 to 100 percent above normal. Even so, water levels in the wells dropped again.
The irrigation era may come to be called the “great pump up,” bookending the other man-made High Plains disaster—the “great plow up,” when 5.2 million acres of native grasses were torn out, setting the stage for the Dust Bowl. “A couple of generations from now,” says Burke Griggs, a water law expert who teaches at Washburn University in Topeka, “people are going to look back and say: What the hell were they thinking?”
The issue of water management is very complicated with usage often regulated by arcane rules that vary drastically by state. As a perfect example, the Ogallala depletion has been most pronounced in Northern Texas where water is not publicly owned allowing landowners to pump as much as they want. In other states like Kansas and Nebraska water is considered a public good and states are able to restrict pumping. That said, limits in Kansas and Nebraska still exceed the sustainable yield of the basin which results in annual declines.
For their part, farmers have invested substantial capital in irrigation infrastructure and water conservation technology in recent years but those advances haven't been enough to offset acreage growth in the region.
Hope lies in technology; farmers show me iPhone apps that track water use so precisely that as little as a tenth of an inch can be applied to their crops. In Colby, Kansas, Lon Frahm, who farms 30,000 acres of wheat and corn, irrigates with two billion gallons of water yearly. He counts among his farmhands an IT technician who collects data to keep his yields ahead of his declining wells.
As the chart below illustrates, in Finney County, Kansas, farmers have been consistently pumping roughly 350,000 acre feet of water from the Ogallala each year which exceeds the sustainable yield of the basin by about 275,000 acre feet or 90 billion gallons annually.
According to research done by NASA's Jet Propulsion Laboratory, the story is the same all over the world with aquifers being depleted at alarming rates.
“The consequences will be huge,” says Jay Famiglietti, senior water scientist at NASA Jet Propulsion Laboratory and lead researcher on a study using satellites to record changes in the world’s 37 largest aquifers. “We need to sustain groundwater to sustain food production, and we’re not doing it. Is draining the Ogallala the smartest thing for food production in the U.S. and globally? This is the question we need to answer.”
The story is virtually the same everywhere. These and other aquifers in several of the world’s most productive, heavily populated regions are being drawn down at precipitous rates. NASA satellites, monitoring changes in Earth’s gravitational pull, found that 21 of the world’s 37 largest aquifers have passed the sustainable tipping point. California’s prolonged drought has driven water levels in much of the Central Valley aquifer to historic lows. India now consumes more groundwater than any other country, and at a faster rate.
Perhaps Saudi Arabia provides the most spectacular example of overdrawing a resource. The Saudis went after the huge Arabian aquifer with a greater passion than they sought their oil, drilling 2,000 feet deep. The dunes turned green with grain, transforming the desert nation into a leading exporter in the 1980s and 1990s. Now the aquifer has been all but emptied. This year wheat wasn’t even planted; the Saudis are growing alfalfa in Arizona and California.
Click the image below for more detail:
If history is any guide, warnings regarding excessive global groundwater depletion will not result in any material change in consumption behavior until it's too late. What happens after that is anyone's guess but there is a saying in California that "whiskey is for drinking and water is for fighting"...we suspect that's not too far off.
A true crisis looms...