By Linden Olson, Worthington
There has been a lot of discussion and a fair amount of ink lately about the serious water situation in southwest Minnesota and the Worthington area in particular, including the relationship of Lakes Ocheda and Okabena to the Lake Bella wellfield that presently supplies the majority of water for the city of Worthington.
There are a few things to keep in mind about the water situation in Worthington and southwest Minnesota. First, southwest Minnesota sits near the top of a drainage divide. Water on one side of this divide flows to the Missouri River, and the other side flows to the Mississippi River. The aquifer beneath southwest Minnesota is not very large and is quite shallow unless wells are drilled into bedrock, and even then the water yield is often not great. Most of the aquifers that feed the Worthington wellfields get much of their water from the shallow prairie lakes, as well as other areas that let water percolate into the sand and gravel beneath them and finally wind up in the area where the city wells are drilled.
These conditions mean that the aquifer feeding local wells - including the Lake Bella wellfield - is highly dependent on annual precipitation and cannot rely for very long on water reserves deeper in the aquifer. According to the National Weather Service, the cumulative total precipitation in the Worthington area for the last 10 years was the most for any 10-year period since 1900. While recent heavy rains have lessened the immediate concern over local well water levels, consider what the situation might be like if precipitation drops to 1950 levels.
The local aquifer stands in stark contrast to the well-known Ogallala aquifer that covers parts of eight states from South Dakota to Texas and lies beneath nearly 175,000 square miles. The Ogallala is estimated to contain nearly 3 billion acre feet of water, or nearly a quadrillion gallons. Is it any wonder why southwest Minnesota wants to connect to the Lewis and Clark Pipeline? As much water as there is in the Ogallala, there is a strong and growing concern that it is being depleted far faster than it is being replenished. The level of the Ogallala has dropped fairly rapidly since 1950 - as much as 300 feet in some locations. Because of this drop, some land that was irrigated in the ’50s to as late as the ’90s is no longer being irrigated because the expense of pumping the water from greater depths became prohibitive. When flying to the southwestern U.S. in the summer from the Midwest you can see the brown, round outlines of areas where center-pivot irrigation systems that once made the area a lush green now sit idle.
The ongoing water problem that Worthington and southwest Minnesota faces is a small example of what a large share of the world’s population will be dealing with in the future. An increasing percentage of the world’s population is living close to the major oceans. This requires more potable water located further and further away from areas where rain falls, causing aquifers where populations are concentrated and other local potable water sources not to be replenished as fast as fast as it is being used. This will merely exacerbate water problems in more and more areas. In addition, some major food production areas are dependent on water for irrigation that comes from precipitation hundreds of miles away. Just this spring large acreages in California, a major supplier of vegetables for the U.S., went unplanted because there was not enough snow the last few winters in the mountains to provide snow melt providing water for irrigation this year.
Even when the Lewis and Clark pipeline becomes a reality, Southwest Minnesota government planners in the area should start now on developing and incorporating water conservation principles into long-range plans. That way, a lack of a sustainable water supply water will not become a major factor limiting population and business growth or cause the region to dry up economically.
