GEOFF BENNETT: In the heart of the country, Great Plains farmers and ranchers produce a quarter of all U.S. crops and 40 percent of our beef.

But they rely on a resource that has been slowly drying up, water.

Stephanie Sy reports from Kansas for our ongoing series on climate change and water, Tipping Point.

BRANT PETERSON, Kansas Farmer: So this is a small glimpse of what the Dust Bowl-type situation was.

STEPHANIE SY: Brant Peterson farms grain in dry Southwestern Kansas, where erratic winds can whip dust into the sky at a moment's notice.

It's difficult land to farm, but Peterson is committed.

BRANT PETERSON: My wife and I are both fifth-generation farmers raising the sixth generation.

We have been to a lot of droughts.

I won't say that it's any worse than anybody else had, but I just do know that what I have had to deal with has been tough.

STEPHANIE SY: Farms like Peterson's are a vital part of the global food system.

Much of the grain he grows heads to the massive cattle feedlots that surround him in Western Kansas, powering the state's multibillion-dollar beef industry.

Nearly a quarter of all the steaks on our dinner plates come from Kansas.

KATIE DURHAM, Kansas Groundwater Management District 1: We are completely dependent on agriculture.

It is the lifeblood of our communities.

STEPHANIE SY: Katie Durham runs the Groundwater Management District in West Central Kansas.

KATIE DURHAM: You just drive around town and anything from our banks to the implement dealers, anything that you see in town is all tightly related to agriculture.

STEPHANIE SY: And the agricultural industry here relies on one increasingly scarce resource.

KATIE DURHAM: Without groundwater, we would really cease to exist.

STEPHANIE SY: Nearly all the groundwater in Western Kansas is tapped from the Ogallala Aquifer, a massive reservoir that runs under parts of eight states from South Dakota to Texas.

But as the darker color on this map shows, parts of the aquifer, especially in Texas, Oklahoma and Western Kansas, are in deep decline.

That's a problem because the economy here relies on water-intensive crops, namely corn.

BROWNIE WILSON, Kansas Geological Survey: We don't have the streams.

It's raining right now a little bit, and that's kind of a little bit unusual.

But what we do have is the Ogallala Aquifer underneath our feet.

STEPHANIE SY: Brownie Wilson of the Kansas Geological Survey regularly measures the water levels at wells like this one throughout Kansas.

He's seen some wells drop more than 100 feet since 2001.

BROWNIE WILSON: What we're doing now is not sustainable.

We track every year the water levels are dropping.

I have seen more places where the aquifer just physically cannot support the pumping demands anymore.

KATIE DURHAM: Depletion between the different layers of the aquifer.

STEPHANIE SY: The depletion isn't uniform.

Durham describes the aquifer's topography as an egg carton.

KATIE DURHAM: You have these pits and valleys, and it's very, very dynamic, and that's why we call it saturated thickness.

And so some areas are going to have more saturated thickness than others.

Likewise, some areas are going to have more decline.

STEPHANIE SY: Unfortunately, Peterson is in one of those areas in Southwest Kansas seeing the state's steepest declines in groundwater.

BRANT PETERSON: I have abandoned over half the wells on my farm.

They're not feasible to pump anymore.

Now, if I wanted to be a water baron, yes, I could pump all year long and make something happen out of it, but I can't sleep at night doing that.

STEPHANIE SY: Because you know how that ends.

BRANT PETERSON: I know where it ends.

STEPHANIE SY: Does that end with the end of livelihoods?

BRANT PETERSON: Yes, but what worries me more is the communities and the people.

That's what you see suffering.

You see the communities drying up with the water.

PETER GLEICK, Co-Founder, Pacific Institute: The overdraft of the Ogallala Aquifer is the result of a whole series of factors.

STEPHANIE SY: Climate scientist Peter Gleick co-founded the Pacific Institute, a global water think tank based in California.

PETER GLEICK: In part, it's because farmers have brought a tremendous amount of land into production and that requires a lot of water.

In part, it's because climate change is reducing the amount of water going to recharge those aquifers.

STEPHANIE SY: According to Gleick, rising temperatures mean crops require more water to grow, even while more intense heat causes rainfall to evaporate before it can reach the ground.

There's also a long established link between climate change and drought, like the one Kansas experienced in 2022, causing record low precipitation in seven Western communities.

PETER GLEICK: A lot of what we're seeing in the Ogallala Aquifer, the depletion of groundwater, we also see, for example, in the Central Valley of California, where every year we see massive overdraft of groundwater.

And in southern part of the San Joaquin Valley in California, we're going to see a lot of land come out of production.

We have to bring groundwater back into balance, or there's going to be serious disruptions of our food system.

STEPHANIE SY: While past generations of farmers saw heavy water use as key to success, attitudes are changing.

STEVE COMPTON, Kansas Farmer: The green zone is the optimal range for the moisture ought to be for this crop.

STEPHANIE SY: Steve Compton grows weed and other grains on thousands of acres in Scott County, Kansas, using a tablet to carefully manage his sprinklers.

STEVE COMPTON: In years past, when it would rain, everybody would just leave their systems on and let them run.

And now, everybody's so conscious of that, when we can get supplemental rain, there's no reason to keep them running.

I like the way those spin around and all the nature just drops around.

STEPHANIE SY: Compton, who became a quadriplegic after a car accident, has always relied on technology to run the farm with his father, Ted.

STEVE COMPTON: We can look at that thing on the Internet and we know instantly what the level of moisture is within that ground out there.

So we know, after a rain, whether we can turn off for a while and conserve some water.

STEPHANIE SY: Even though none of the wells on his farm have run dry, Compton, along with all the other farmers in his county and three neighboring counties, have committed to cutting their water use by up to 25 percent.

Katie Durham worked with farmers to pass local agreements to manage and implement water use reductions in her district following success with them in Northwestern Kansas.

KATIE DURHAM: People really saw this as an opportunity to take local control.

I probably sat with a few hundred people just having conversations about what this meant, how it would affect them.

And I think really the big question was, what is going to happen if we don't do something?

STEPHANIE SY: For Compton, it's about being a good steward of the land and resources.

STEVE COMPTON: The farmer loves the land and he loves what he does.

And we're going to do whatever we can to maintain that type of life and to be able to pass that on.

STEPHANIE SY: Back down in Southwest Kansas, which has seen the steepest declines, no restrictions are in place to control overpumping.

BRANT PETERSON: Everybody has a right to drive themselves into bankruptcy, but somebody's got to stop, somebody's got to back off.

And so that's what I did.

And I have sought other technologies to help me be more efficient.

The challenge is the fun part.

The sadness of, yes, we're losing the water, that's what stinks.

STEPHANIE SY: He's invested in a new irrigation system that uses water more efficiently, and he's begun to replace thirsty corn crops with fields of sorghum, a resilient grain that can be used to feed cattle and people.

Overall, Peterson has reduced his water use by 15 percent.

And for him, that means his sons may have a shot at carrying on the family business.

BRANT PETERSON: Conserving the water is a big part of them having the opportunity to be successful here, to have a sound economy around them to support the operation.

And that would be fantastic.

STEPHANIE SY: Whether or not the voluntary conservation efforts of farmers will be enough to preserve the way of life here remains as uncertain as any given day's weather in Western Kansas.

For the PBS "News Hour," I'm Stephanie Sy.