Ogallala Aquifer | What Happens When the Water Runs Out, National Geographic Magazine: Crop Circles
Center-pivot irrigation systems etch circles of grain and other plants in Finney County, Kansas. These self-propelled, rotating sprinklers revolutionized farming, enabling more land to be irrigated efficiently. As the aquifer declines, some farmers only irrigate partial circles. Generally each sprinkler needs to draw from a well that can produce a minimum of 400 gallons of water a minute.
Aerial is between Dodge City and Garden City, Kansas as a rainbow appears after a storm. Corn is king and a water hungry crop. Switching to milo and bison could save the aquifer for the next generation. A center pivot pumping 694 gallons a minute can pump a million gallons a day. Rain measures roughly 18 inches years in this region and a center pivot adds an additional 18 inches or more. Most of the pivots in the 70’s pump water out at 1,000 gallons a minute.