“The Ogallala Aquifer will be gone in fifty years!
“In twenty years!”
“The Ogallala recharges and has gained thickness over the past two years.”
Which of these is true? The answer is yes, depending on where you are, and what uses you are talking about. Because the Ogallala is very large, and exceedingly variable in thickness, surface-water access, and usage over the length and width of the formation. The climate shifts from north to south and east to west, adding further complications.
The Ogallala is a layer of sand and gravel that was deposited between two and six million years ago. Enormous rivers flowed off of the then-young Rocky Mountains, eroding the fast-rising peaks and dumping thick layers of sediment all over the plains to the east. this sediment remained loosely-packed and porous, even after it was covered in tens to hundreds of feet of soil and dust and sand. Because of water-resistant layers of stone underneath it, the Ogallala catches incoming surface water and acts as an aquifer. You can drill a well into it and bring up good, if somewhat mineral-laden, water that has been filtered by the sand and by time.
If you are up in the Nebraska Sandhills, on the northern end of the aquifer (the indigo-blue blob), rainfall and snowmelt sink into the formation, helping to recharge it. In some wet years, and some parts of the Sandhills, the aquifer will gain water and the water table rises to the surface. In dry years, when people have to pump a lot for their cattle and to irrigate fodder crops, the level drops.
Farther south, the thickness of the aquifer tapers off, and the climate is drier and warmer. Here, the use of the aquifer, especially since the invention of center-pivot irrigation in the 1950s, has dropped the level ten, fifty, hundreds of feet. Some counties in Kansas have reached a point where it is no longer cost effective to pump from the aquifer (depth to water of 600′ in a few places) and have reverted to pasture and to dryland crops. At the far tail end of the formation, near La Mesa, Texas, the aquifer was never thick to start with, and it hit close to bottom in the 1960s just from private and municipal wells.
Most of the area now has Groundwater Protection Districts that regulate consumption, either through voluntary mutual agreement, or force of law. It depends on the state, the state’s water-laws, and when the District came into being. Some Districts focus on keeping water in the ground for perpetuity, others are trying to slow draw-down so the water will run out no sooner than, oh, 2100 or so. Everyone agrees that conservation is needed, and is good, and that the more efficient use we can make of the water, the better off all of us on the aquifer are. It’s just how to do that, and what the best use of the water might be that we politely disagree over. OK, loudly disagree, with the occasional shoving match, especially when outsiders pop up and announce that they are going to drain the water and send it: downstate, out-of-the-state, or to The Big City. Nothing unifies people like a common enemy.
The main use for the water is farming. Watering crops, watering livestock, and processing livestock are major uses. A pork-packing plant was proposed for part of southwest Kansas back in the 1990s. It was denied permits because pork processing takes at least three times the water per carcass as does beef packing. Irrigation has come a long way in terms of efficiency, from the old flood-furrow system where farmers moved lengths of pipe by hand, poured water onto the soil and then moved the pipes again, to modern low-flow, low-height nozzle center-pivot systems, to in-ground drip irrigation with built in moisture meters that only release water when and where it is needed by the plants. The cost has risen with the complexity, but water use per acre has decreased markedly. The development of low-moisture hybrid wheats and other grains, plus some experimentation with arid-region grains such as teff, has further reduced the need for irrigation water per acre, at least in average to moist years.
People also drink the water, enjoy swimming in reservoirs, and complain about the flavor and what the mineral-rich water does to your teeth. (They are stronger, and slightly brown from the fluoride.) Lots of people, millions of people, who brush, and flush, and shower, and water lawns not designed for the climate, and wash cars, and build pools and . . .
Ahem. Sorry. The wandering soapbox jumped me. I have some personal beefs with open pools and blue-grass lawns in semi-arid places.
Since this is already getting long, on Friday I’ll continue and we’ll look at hard numbers, playa lakes and springs, and different thoughts about the future of the region.
(Edited to change date of part two. I wrote 5000+ words on Monday and my brain is numb.)