15 July 2012

What will happen when the Ogallala runs dry ?

Mulligan began laying out a series of poster-size maps of the Panhandle. The first showed the base of the aquifer in burgundy. During the late Tertiary Period, he explained, the region we know as the Great Plains wasn’t composed of plains at all—it was a stony terrain of cliffs and valleys. Gradually that surface was buried by erosion sediment from the Rockies, which blanketed the region with the smooth surface of today’s plains. But underneath, the hills and valleys of the prehistoric landscape remain, forming the bottom of the Ogallala Aquifer.

Mulligan spread out a second map on top, which showed the same region, but in shades of blue instead of burgundy. “This is the saturated thickness of the Ogallala in 2004,” he said. “So that’s basically the available water.” The contours of the prehistoric landscape remained clear: where there had been hills, the water was shallow, and where there had been valleys, the water was deep.

Next Mulligan spread out a map recording the impact of wells, which were represented with hundreds of tiny dots. The burnt-orange shading on the map indicated a rapid rate of depletion. Mulligan said, “What you’re looking at is a drawdown on the order of five to six feet per year. So over the last fifteen years, it’s gone down eighty, ninety, one hundred feet.”

None of which, he went on, is likely to come back. For complex reasons involving wind, weather, and soil composition, the Ogallala does not recharge in the way one might expect. In fact, of the eight states above the aquifer, only Nebraska, with its sandhill dunes, is permeable enough to contribute any serious replenishment.

Now Mulligan spread out the last two maps of the region. The first was covered with crimson spots. “So what we did is, we highlighted all the areas that are less than thirty feet,” he said. “Thirty feet is kind of a magic number. You’re down to so little water that you’re not going to be able to pump nearly enough.” The map was almost a quarter red. “So that’s 2004,” he said, turning, “and this is 2030.” 

In the last map the Panhandle was nearly all red. “I look at that,” Mulligan said, “and I can only surmise that there will be very little irrigated agriculture on the high plains twenty years from now.”

“It’s hard to imagine what there will be,” I offered.

Mulligan smiled. “Just because we’re all born into this, we think that’s the way it’s supposed to be. But our human perspective is very biased.” 
Text excerpt and image from a fascinating article in this week's Harper's Magazine, entitled "Broken Heartland.  The looming collapse of agriculture on the Great Plains."

None of this is particularly "news."  I believe it's been known for decades that the water level in the aquifer is declining and will eventually be depleted.  The Texas/Oklahoma area cited above is particularly susceptible to depletion; there are other maps at Wikipedia showing the depth (and drawdown) of the aquifer in more northern states.  But with continued irrigation for agricultural purposes, it will gradually run dry.

What happens then?  That's what the article is about.  Some interesting ideas.


  1. I won't pretend to understand much about the rights required to drill for minerals, oil, and water under the ground. I've certainly never understood how one individual (T. Boone Pickens) has been able to acquire the rights to vast portions of the Ogallala Aquifer. No doubt some of it is intended for local use and irrigation, but his plans to pipe water more than 250 miles to supply Dallas, TX with additional water really disturbs me. Yes, Dallas is a large metropolitan center, but it also receives considerably more precipitation (primarily through spring and summer thunderstorms) than most of the Great Plains. As Dallas' water requirements are expected to grow, it seems criminal to drain water from the Ogallala at the expense of the plains states.

  2. Seems like some of those Texas oil tycoons have enough money to start up a desalinization plant on the gulf. I think somewhere in Australia they realized that it was a horrendously expensive endeavor (creating a desalinization plant), but still cheeper than running out of water.

  3. Water law is a pretty fascinating topic and Texas has the most unique position of any state in the US. Landowners in Texas have exclusive rights to what is underneath their property ("rule of capture" technically, or hilariously "law of the biggest pump"). It's not that they own it per se, but if they can get to it, it is theirs to use. So it's a free-for-all and very Texas, of course. This is why Pickens is able to do what he does.

    It doesn't make much sense in modern times, most sane people can recognize that. In the places where water law matters the most (the midwest and western states), these rules were all fixed in the frontier time. Nuance wasn't always part of the equation, and the big property owners often had the biggest hand in developing the system of course.

    Regarding the Ogallala, well...it should be interesting.

  4. The Great Plains will before too long be called simply, "The Steppes".

  5. What happens then? I just read this this morning:

    "So, while I followed the arguments and impact assessments with interest, it was the commentary on potential contamination of the Oglala Aquifer from any pipeline leak or spill that caught my attention. Then the real reason for the Keystone project hit me: the whole thing has little or nothing to do with oil from the Alberta tar sands.

    Keystone XL is all about water."

    Here's the link http://peterdenton.ca/2012/07/12/is-keystone-all-about-water/

    1. That's a very interesting idea. It would, however, require politicians thinking ahead toward the future. But maybe the businessmen did that for them.

      Very interesting...

    2. The issue of water going south has been a topic of interest in Canada for some time. Not if, but when...and how: Will we sell it? Give it away? Keep it for ourselves?

      Or will we have the choice taken away from us by the very business men that seem to do the forward thinking for the politicians, as you suggested.

  6. While artificial recharge of the aquifer won't save the day, it will slow depletion. There is some notable work in this field that looks at methods to increase the recharge to the aquifer. The other key word should be conservation.



    Mision 2012 has a good website looking at possible soutions to the aquifer depletion problem.



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