Rex Buchanan returned recently to Lawrence from his annual tour of water wells in western Kansas.

As interim director of the Kansas Geological Survey, one of his jobs is to drive through the region each January and take measurements from about 1,400 water wells that tap into the vast underground reservoir called the Ogallala Aquifer.

That’s a pool of underground water locked inside the pores of gravel and sand lying several hundred feet below the surface. It stretches across several states, from Nebraska to Texas, including about 30,500 square miles in western and central Kansas.

There were few surprises in this year’s survey. The water tables have dropped since the year before, by a lot. There was a drop of about three and a half feet overall, he said, with a little more in northwestern Kansas, which was especially dry in 2012. In southwestern Kansas, which saw a little more rain last year than the year before, the decrease wasn’t quite as severe.

“Just as a matter of perspective, the declines we saw last year when we measured in January 2012 (when declines averaged 4.25 feet), those were the largest declines we’ve ever seen in the time we’ve been doing this program,” Buchanan said. “The declines that we saw in January 2013 were the second-largest declines.”

The question that many people are now asking — and the one for which nobody has a firm answer — is how much longer that can continue.

“That has been the 35-year conversation,” said Mark Rude, executive director of Groundwater Management District No. 3, which governs water resources in much of southwestern Kansas. “It’s that proverbial conundrum, if you will, between economic opportunity and sustainability.”

A groundwater-based economy

Most of western Kansas has a semi-arid climate, meaning it’s not quite a desert, but it tends to lose slightly more water through evaporation each year than it receives in precipitation. That makes it naturally suitable for growing wheat and other kinds of grasses, which is what most farmers there did from the pioneer days through the mid-20th century.

In the 1950s, however, a new invention called center-pivot irrigation, farmers were able to tap into the aquifer lying 200 to 500 feet below the surface. Those giant, rotating sprinkler systems form the circular fields that are so visible from airplanes flying over.

Irrigation greatly increased the production capacity of the region and enabled farmers to grow more water-intensive and higher-value crops such as corn and sorghum. That helped attract much of the U.S. cattle industry to the High Plains, and helped spawn another industry in the region, ethanol production.

As a result, much of the region’s economy today is based on “mining” water from the ground to support a kind of agricultural production that otherwise would not be possible in such a climate.

The problem, according to Buchanan, is that even in a normal year, the aquifer only recharges at a rate of about a half-inch per year. But farmers, ranchers and the city water utility systems there are pumping water out at a rate of two to four feet per year, sometimes more. And that rate only increases during periods of prolonged drought such as the one the region is now experiencing.

At the groundwater management district office in Garden City, Rude says the handwriting is on the wall.

“There’s no question about it, we’re running smack dab into the limitations of the aquifer itself today and the demand placed upon it by those pumping wells,” he said.

Conservation may only be buying time

Under Kansas law, all water resources are considered public property, belonging to the people of Kansas generally, and the right to divert water from a river or stream, or to pump it from underground, for anything other than domestic household use is strictly controlled by the state.

In recent years, as water tables in certain parts of the Ogallala Aquifer have declined sharply, state and local officials have imposed several measures aimed at conserving the resource.

Starting this year, for example, Groundwater Management District No. 3 is imposing stiffer penalties for users who pump more than their permits allow, with fines up to $10,000 and a one-year suspension of water rights for repeated violations.

Another measure has been to close off large areas of the aquifer to new water right appropriations. According to maps published by the state Department of Agriculture’s Division of Water Resources, most of southwestern and south-central Kansas are now covered by those closures.

According to Rude, that has had far-reaching economic consequences, one of which has been to drive up land values in the area, as well as the value of the water rights themselves, tangible assets that can be bought, sold or even temporarily transferred from one party to another. But as data from groundwater surveys shows, it hasn’t stopped, or even slowed, the rate of depletion in the aquifer.

In Dodge City, the municipal government has also taken measures to conserve water. City manager Ken Stroble said the city recently installed a new kind of water reclamation facility that recycles the city’s wastewater so it can be used as a source of irrigation water.

“The water reclamation is kind of a state-of-the-art facility that actually purifies the wastewater – they call it grey water – to the point where you can’t drink it, but you can use it for public ground irrigation,” Stroble said. “We are now irrigating our public golf course with the grey water instead of fresh water.”

Meanwhile, state officials have tried to encourage farmers who irrigate to shift to dry-land farming to reduce demand on the aquifer. But Buchanan at the Kansas Geological Survey says that has had only limited success.

“At the same time all of this has been going on, commodity prices have been going up – wheat prices and corn prices,” he said.

The bottom line, officials say, is that the water resource of the Ogallala Aquifer is limited, and it’s being used up faster than it can be replenished. That leaves everyone asking how much longer the economy of western Kansas can remain dependent on that resource.

“It’s essentially fossil water we’re mining,” said Rude at the groundwater management district. “So you either say we’re done and we have no more economy, which we’re not going to do, or you say let’s make every drop count. That’s the focus of the conversation. The only other option is the importation of water.”