Farmers in Kansas and other states that sit atop the Ogallala aquifer – the largest freshwater aquifer in North America – are pumping out water for crop irrigation far faster than natural seepage of rainwater can replenish it. Scientist David Hyndman from Michigan State University is helping develop a plan to better manage this vital resource for sustainable farming. "Sustainability: Water" is produced in partnership with the National Science Foundation.
Sustainability - Water - The Ogallala Aquifer
ANNE THOMPSON, reporting:
In the state of Kansas, agriculture is king. Along with high yields of corn and soybeans, Kansas is the top wheat-producing state in the U.S., with yields of more than 382 million bushels in 2012, according to the USDA. The secret to this land's bounty is not just the soil that covers it, but also something below ground that no one can see - the Ogallala aquifer, the largest freshwater aquifer in North America.
DAVE HYNDMAN (Michigan State University): For decades you've had incredible production of agricultural crops on top of this and largely that's because of the incredible water resources that have been available to it.
THOMPSON: The Ogallala Aquifer, also known as the High Plains Aquifer, is a groundwater storage reservoir that stretches 174,000 square miles underneath parts of 8 states from South Dakota to Texas.
STAN TOWNSEND (Western Kansas Farmer): This well here is 303 foot deep.
THOMPSON: Stan Townsend, a sixth-generation farmer from Weskan, Kansas, grows corn, wheat, pinto beans and peas on his land. Like many farmers, Townsend depends on the aquifer to irrigate his crops, especially during times of extreme drought.
TOWNSEND: This country is about weather, and right now, it's sure not in our favor.
THOMPSON: Today's irrigation technology is able to pump out water that has been in the aquifer for hundreds of thousands of years in just a matter of minutes, a rate which far outpaces how fast nature can replenish it, threatening the overall sustainability of the aquifer and agriculture.
TOWNSEND: This well over on southwest was right at a 2,000 gallon a minute well and now all we're gettin' out of it is about 600.
THOMPSON: According to the Kansas Geological Survey, groundwater levels in the aquifer have dropped an average of 14 feet since 1996 - about a foot each year. Aquifer drop-rates suddenly doubled, an average of two feet a year, between the start of 2011 and the end of 2012 alone.
HYNDMAN: Since about 2011 there's been a significant drought and this is really across most of the high plains aquifer but this area, as well as others, you're now in a period of extreme to exceptional drought.
THOMPSON: Dave Hyndman, a hydrologist at Michigan State University, is leading a team of scientists funded by the National Science Foundation that is studying the aquifer. The team is analyzing data from as far back as the 1800's on changes in climate, irrigation technology and water policy to build models that could forecast what the future holds for the aquifer and for farming.
HYNDMAN: When we feed the climate into these models, we're able to predict what happens with the water levels and as long as we have pumping data, we really get a great understanding of the system.
THOMPSON: One of the reasons why the aquifer replenishes or recharges so slowly is due to the water cycle itself. When precipitation in the form of rain or snow hits the ground, some of it runs off. Some evaporates back into the air from the ground or as transpiration from plants. What doesn't run off or evaporate slowly seeps down through the soil and its layers by gravity in a process called percolation. In western Kansas, it can take one year to recharge the aquifer by just one inch.
JIM BUTLER (KANSAS GEOLOGICAL SURVEY): The bottom line is there's not enough recharge out here. Not enough precipitation.
THOMPSON: During the drought of 2012, Mitchell Baalman, a fourth-generation farmer outside of Hoxie, Kansas, was able to maintain his crop yields only by pumping more water out of the aquifer.
MITCHELL BAALAM (Western Kansas Farmer): In 2012, we were drastically impacted. I mean, it affected our crops, definitely affected the aquifer. We depend heavily on the Ogallala, which we're pumpin' out for our pivot irrigation.
THOMPSON: Now in an effort to extend the life of the aquifer, Baalman and other farmers have started a grassroots effort to cut back pumping by 20 percent over the next five years.
BAALAM: I think we're averaging probably 2.1 foot a year is what we're droppin'. That's why we're lookin' ahead to the future to try to promote saving, being proactive instead of reactive.
THOMPSON: But sustaining the Ogallala aquifer and Kansas agriculture must also include more scientific research. Hyndman's team is working with local and state government officials, water policy experts and farmers to develop a long-term model for aquifer water use - based on more precise measurements of precipitation, percolation and natural recharge, better monitoring of agricultural pumping, and forecasts of changes in climate and population.
HYNDMAN: To do anything about sort of forecasting what happens in the future, we have to work with both the farmers and the policy-makers, because as we do these scenarios of the future, we have to have a pretty good idea that the scenarios we're running are feasible.
TOWNSEND: We've gotta start someplace. We gotta get this thing moving. It's too important.
THOMPSON: Improving water policy and reducing water usage are not only key to sustaining the Ogallala Aquifer, but also to maintaining a way of life in western Kansas and across the entire High Plains region.
The Great Plains stretch from Canada to Mexico across the midsection of the country and consist of relatively flat plains that span from mountain elevations to sea level. The Plains are made up of a broad range of ecosystems, including forests, rangelands, marshes and desert. This coincides with a highly diverse climate and large geographic variation in temperature and precipitation across the region.
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