Long ago, the middle of the North American continent was a treeless prairie covered by tall grasses and roaming buffalo. When European settlers came, they called this area the Great American Desert. Today, this "desert" is covered with fields of wheat, corn, and alfalfa made possible by center-pivot irrigation. My grandfather used to sell center-pivot systems and when my family drove to my grandparent's home in Nebraska, we would count how many "sprinklers" were watering each section of land. At the time, I didn't know that this water was being pumped from somethng called the Ogallala Aquifer, a huge underground water supply. Throughout the years, this aquifer has made the Great American Desert one of the best farming areas in the world. Unfortunately, the Ogallala Aquifer's future as a valuable resource is in jeopardy, unless citizens of the Plains states reduce their water consumption.
Background of the Problem
To understand why the problem is important, it is necessary to know some basic facts about the Ogalla Aquifer. This underground reservoir covers 174,000 square miles. According to John Opie, author of Ogallala: Water for a Dry Land, the Ogallala was formed over the course of millions of years as the land flooded, dried out, and flooded again. As centuries passed, glaciers melted, carrying water, silt, and rocks from the Rockies down to the Great Plains to form the Ogalla. Dirt, clay, and rocks accumulated above it so that the waters of the Ogallala can now be reached at depths of 300 feet beneath the surface (29-35). Some people think that the Ogallala is a huge underground lake, but this idea is wrong. As Erla Zwingle puts it, an aquifer such as the Ogallala is like a "gigantic underground sponge"(83). The water fills in the spaces between the sand, silt, clay, and gravel that make up the Ogallala formation. This 1,000 feet; the average thickness, however, is about 200 feet (Zwingle 85). The aquifer reaches its deepest points under the state of Nebraska, which is not surprising because most of the because Ogallala's water lies beneath this state. The rest lies under Colorado, Kansas, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming.
Th Ogallala Aquifer is the largest "underground sponge" in the United States. It contains more that 977 trillion gallons, or three billion acre-feet of water. (An acre-foot is 325,851 gallons, or the amount of water it would take to cover an acre to the depth of one foot.) According to Jack Lewis in the EPA Journal, the water contained in the aquifer is enought to fill Lake Huron pluse one-fifth of Lake Ontario. "If pumped out over the United States," Lexis writes, "the High Plains aquifer would cover all 50 states with one and one-half feet of water."
The Nature and the Extent of the Problem
Each year, at least 7.8 trillion gallons of water are drawn up from the Ogalla Aquifer to irrigate the crops planted on the High Plains. These cros are...