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Fluid Journal : Summer 2014
7 The Fluid Journal Summer 2014 There are no easy answers to protecting our surface and underground water resources. Summer 2014 • Vol. 22, No. 3, Issue #85 Dr. Raun Lohry and Dennis Zabel Summary: Complex problems cannot be solved simplistically. Balancing the social, ecological, economic, and agricultural interests in water will be clearly complex. Protecting our surface and underground water sources will require a holistic approach. Solutions will be regionally based but implemented and applied appropriately on a farm scale. Water is an essentially fixed entity in the world. No more will be created. Water has, over time and civilizations, been worshiped, managed, and wasted. It has been responsible for the rise and fall of kingdoms and empires. It has been fought over and generously given as a source of life. As Benjamin Franklin once said, “When the well’s dry, we know the worth of water.” In this article we will take a fleeting glimpse into water and irrigation issues in the Great Plains. Like other regions of the world, the Great Plains has to balance water for farming and water for its citizens. Farming feeds people and it economically supports those who provide food for the world’s growing population. Irrigation increases yields, allows a myriad of crops to be grown, and mitigates weather uncertainties in crop production. Irrigation water is derived from surface water and deep wells. Wells extract water from subsurface aquifers but sometimes surface water and aquifers are intimately connected. Two examples of the complexities of these relationships are the interactions that come out of extracting water for irrigation from the Ogallala aquifer, and the legal, economic, and political conflicts from the Republican River system. Overflow Deficits of water are not the only problem in the Great Plains. In northern South Dakota and across North Dakota, lakes are increasing in surface area and depth due to increased precipitation and runoff over the past several decades. Devils Lake in northeast North Dakota is a good example of where too much water is a massive problem. Between 1993 and 2011, levels on Devils Lake rose 31.68 feet. Surface areas of the lake increased from 44,230 acres to 211,300 acres. That is an additional 261 square miles of land covered with water. The volume of water has grown by 7 times in that time period. North Dakota State University expects the water body to inundate an additional 10,000 acres in 2014 with millions of dollars lost in economic activity. Roads, highways, and railroads have been raised to avoid being permanently inundated. Hundreds of buildings have been lost to flooding or have been moved. Hundreds of residents have abandoned their homes and farms through “buyouts” where a state agency buys the land. Some have called it the “slow moving monster.” Ogallala formation The largest of these aquifer systems, the Ogallala formation, is shown in Figure 1, with a concentration of water appearing underneath Nebraska. The steady increase in Nebraska irrigation led to that state being number one in the nation for irrigated cropland. The 2007 Census of Agriculture reported that Nebraska had more than 8.5 million acres under irrigation. Nebraska had more irrigated farmland acres than any other state, accounting for about one in every 6 acres of US irrigated farmland. The 2012 Census of Agriculture reported that Nebraska had about 8.2 million acres under irrigation and California had about 7.8 million acres. Between 1988 and 2007 corn accounted for 70 percent of the irrigated acres in Nebraska; soybeans accounted for 19 percent (Figure 2). A 2003 survey suggested that 72 percent of the irrigated acres were center pivot systems and 28 percent were gravity irrigation systems, with the most common gravity systems being furrow irrigation. Subsurface drip irrigation systems were used on only a small portion of the land. 1942 agreement Progress has its consequences. It would’ve been impossible for anyone to predict the impacts of the increase in irrigation. In 1942, the states of Colorado, Nebraska, and Kansas joined together to form an agreement called the Republican River Compact. This was necessary before the Crops of Engineers would agree to build Harlan County Reservoir on the Republican River to reduce downstream flooding. A disastrous flood in May/June of 1935 killed an estimated 113 people and perhaps as many as 41,000 head of livestock. This multi-state agreement was ratified by Congress and approved by the Supreme Court. In it, the authors determined that Colorado was responsible for about 11 percent of the beneficial consumptive use of the Republican River drainage system. Nebraska was allocated about 40 percent and Kansas 41 percent. Despite best intentions of the states to adhere to the compact, progress is taking its toll. Colorado now pipes water from deep wells into the Republican River system and has been forced to drain the reservoir in Bonny Lake State Park, a locally popular recreation area, to make up for over-allocated consumption Nebraska is also diverting water from deep wells into Republican River feeder streams and yet is still the brunt of Kansas lawsuits claiming up to $72 million in damage. Prosecuting the defending lawsuits is expensive for all involved.