The Bread Basket of the World
By Gabriel Medina
The fertile soils of Nebraska and other Midwest states feed millions of Americans with different kind of crops, thanks to the water from the High Plains Aquifer. But University of Nebraska-Lincoln groundwater geologist Jesse Korus said that the region has a worldwide impact.
"We've heard of the High Plains region being called the bread basket of America," Korus said, "but it is really the bread basket of the world in some respects. It overlies this major aquifer, which can help us to sustain irrigated agriculture. For that reason the High Plains Aquifer is probably one of the most important in the world."
At least 20 percent of the total irrigated land in the United States overlies the High Plains Aquifer and 66 percent of it is under Nebraska, said UNL geologist Matt Joeckel.
A quadrillion gallons of water are contained in the High Plains Aquifer, which would be enough to fill Lake Huron. The Ogallala Aquifer is a major part of the High Plains Aquifer.
Even though Nebraska is fortunate to have this enormous quantity of water, there are some places where its levels are decreasing.
"Some estimates indicate that, at current pumping rates, there may be only between 25 and 50 years of use left in some parts of the High Plains Aquifer," said Korus.
Joeckel, who is also the outreach coordinator of the Conservation and Survey Division of the UNL School of Natural Resources, pointed out that the term "sustainable" is not appropriate when referring to water use from The High Plains Aquifer. He explained that, according to some definitions, sustainability would mean that the water level declines stabilize. But because that is not happening, he prefers the term "wise-use."
"I would certainly be concerned about places south of the Platte River in Nebraska," Joeckel said, "where water levels in the High Plains Aquifer have dropped significantly since development began around 1950."
Joeckel added that water levels of this aquifer have also decreased in certain parts of Kansas, the Texas panhandle and the Oklahoma panhandle. These decreases of 100 feet or more in the water level worry Joeckel because it is possible there soon won't be enough water for irrigation.
"Many people around the world derive some kind of indirect benefit from the use of waters from the High Plains Aquifer. So, in that sense we all bear some responsibility," said Joeckel.
There are certain areas of the High Plains Aquifer near Nebraska's Platte River Valley, as well as in Holt county of Nebraska that are polluted with fertilizers, according to Korus.
To stop, or at least decrease this pollution, the Natural Resources Districts of Nebraska as well as UNL's Extension personnel are educating farmers about the proper use of agricultural chemicals.
"Generally, these producers want to be good stewards, they want to do the right thing," Korus said. Korus explained that the pollutant level in the High Plains Aquifer is being monitored by the Nebraska Department of Environmental Quality and the Natural Resources Districts.
Joeckel explained that people have certain misconceptions about the High Plains Aquifer. The most important one is that an aquifer is an underground lake, but it in reality it is similar to a sponge made of sand and sedimentary rocks that are porous enough to hold water.
"An even better analogy would be filling up with sand a pint glass, and then running water into it until the sand was wet- but you could not see any liquid over the surface- and then putting a straw in and trying to suck the water out," he said.
Another misconception is that the aquifer underlies all of Nebraska, but the truth is that it doesn't underlie the southeastern corner of the state, where most of the population lives, Joeckel said.
Joeckel pointed out there are other misconceptions, like the fact that there is no relationship between underground water and surface water.
"There are certainly large stretches of major rivers in Nebraska that are gaining flow from groundwater," he said. "The flow in many of Nebraska's streams is related directly to the High Plains Aquifer, whether water is going into the aquifer or coming out of it."
Joeckel also stressed that the High Plains Aquifer is the major source of fresh water in all of Nebraska, for drinking, agriculture and every other use.
Other World Aquifers
With 3 billion acres of water, the High Plains Aquifer is not the biggest in the world, but it is very important because of its location. The Great Artesian Basin in Australia has 7 billion acre-feet of water and The Guarani Aquifer System located between Brazil and Argentina contains 24 billion acre-feet of water.
"There are much larger aquifers in the world than the High Plains Aquifer, but what makes the High Plains Aquifer so special is that it overlies a region of high agricultural productivity, of good soils and ideal climate for certain crops," said Korus.
Taking Care of Water
Korus explained that Nebraska is divided into 23 different Natural Resources Districts. Some of these districts regulate how much water a particular farmer can use in any irrigation season.
Recently, Nebraska has been given the authority to stop additional development of groundwater supplies where it has impacted surface water supplies.
Korus said that there have also been disputes related to surface water supplies between states.
"Kansas has disputed Nebraska's use of ground water because it reduces the amount of water flowing in the Republican River," he said.
Korus explained that groundwater and surface water are interconnected, so if there is a surface water dispute and that surface water is connected to groundwater, then the dispute becomes a groundwater dispute.
"Part of my job here at the university is to help people to deal with ground water issues," said Joeckel. "My personal interest lies along the lines of the materials that actually make up the aquifer, not the water, but the materials holding it, the sediments, particularly in the Ogallala formation."
Joeckel said a drip irrigation system is a method that helps to conserve water. With this technique, water is applied slowly to the plant's roots, so only about 10 percent of the water evaporates. If the water is sprinkled over all the plants through conventional irrigation systems, between 15 and 25 percent of the water is lost through evaporation.
"With strategies like this one, we get the most out of every drop of water," Joeckel said. "We've not been very good to our aquifers on a global basis. So, we can learn a lot about how to use them better and make them last."
Korus said he became interested in his job because water has helped Nebraska to develop and have an important economical growth.
"I've seen how irrigation has benefited this state in terms of its agriculture and because of that I want to make sure that I'm doing what I can to help protect those supplies for future generations."
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