DAVID GREENE, HOST:
And now to a moment of reckoning in one farm state. Scientists in Kansas are predicting that agricultural production in Western Kansas will start declining in about 25 years because of a lack of water for irrigation. Scientists say farmers might avoid this by conserving water now.
NPR's Dan Charles reports.
DAN CHARLES, BYLINE: David Steward, a water expert at Kansas State University says he and his colleagues started their research with some specific people in mind.
DAVID STEWARD: The family farmer who's trying to see into the future, and trying to pass on his or her land to their grandchildren.
CHARLES: Every farmer in Western Kansas knows there's reason to worry. Big irrigated fields of corn in this part of the country are taking water out of underground aquifers much faster than rain or snow can fill those natural reservoirs back up.
Steward decided to come up with better estimates for how soon the aquifers will go dry, and how that will affect farmers. He worked with experts on growing corn and raising livestock.
STEWARD: We were trying to provide a little bit better glimpse into the future, so that people would have a better idea for how to plan.
CHARLES: According to their calculations, if Kansas farmers keep pumping water out of the High Plains Aquifer at the current rate, the amount of water they'll able to extract will start to fall in just 10 years or so.
Their harvest of corn will still keep growing until about 2040 because technology - like better irrigations systems and new corn varieties - will let them use water more efficiently. But after that, even technology won't save the corn fields. They'll start to disappear. So will cattle feedlots. The long expansion of agricultural production in Western Kansas will be over.
Now Steward also lays out in his calculations some alternative paths that the farmers of Kansas could take. For instance, if they used 20 percent less water starting today, they'd cut their corn production a lot, but it would keep going for much longer. It wouldn't peak until 2070 and then it would decline much more gradually.
STEWARD: If we're able to save as much water as possible now, the more that we save, the more corn we'll going to be able to grow into the future.
CHARLES: These predictions appear in this week's issue of the Proceedings of the National Academy of Sciences.
Their forecast isn't really a surprise. Farmers in Western Kansas have been talking about the end of easy water for decades now. In some areas, wells have already gone dry. Thirty years ago, local governments in some parts of Kansas set up groundwater management districts to discuss the problem and also ways to solve it.
Mark Rude, executive director of the Groundwater Management District for Southwest Kansas, says it can be an emotional discussion.
MARK RUDE: Because there's nothing really more fundamental to the local family farm than the water supply to that local family farm.
CHARLES: At the same time, he says the families on those farms do want to find solutions; they want their grandchildren to have plenty of water, too. Rude says in his district they've had discussions about various ideas for how to reduce water use. But it's mostly talk so far, not much action, for a very practical reason. His agency may not have the legal authority to force farmers to cut back on their water use. Those farmers own rights to water the way they own land. Any rule that tries to restrict that right could be challenged in court.
RUDE: The last thing people really want to see is simply a whole lot of court cases.
CHARLES: The only way to avoid that, Rude says, is to come up with a plan that everybody can live with.
There's a model for this. In one small area in Northwestern Kansas, farmers have agreed to use 20 percent less water for the next five years.
RUDE: It's an experiment. A lot of people are watching that, and of course, that figures prominently in the conversations of if we were going to do it, how would be do it?
CHARLES: And if they can't agree to cut water use, eventually the natural laws of hydrology will step in. Farmers will use less water when the wells go dry.
Dan Charles, NPR News.