Submitted to: Proceedings of the Central Plains Irrigation Conference
Publication Type: Proceedings
Publication Acceptance Date: January 31, 2006
Publication Date: February 21, 2006
Citation: Heermann, D.F. 2006. Impact of variable well yield on center pivot packages. Proceedings of the Central Plains Irrigation Conference. p. 25-34. Interpretive Summary: The continual development of irrigation in the High Plains of Colorado, Kansas, Texas and Nebraska has exceeded the available water supply. Center pivot systems have installed at a rapid rate during the expansion of irrigated acres. The increase in irrigated acres has led to large declines in drawdown of the groundwater levels. The analysis demonstrated the need to over design the pumping plants or at least a continual monitoring of the systems with increased drawdown and modifications necessary to prevent the center pivot systems to decrease in efficiency.
Technical Abstract: The effect the continuing decrease on water levels have on center pivot irrigation systems is analyzed. Area weighted average water level changes are -1.0, -1.7, and -1.3 feet in the states of Colorado, Kansas and Nebraska. The 2002-2003 water level changes varied from a rise of 9 feet to a decline of 14 feet. There were significant areas that had ground water declines in excess of 5 feet in a one-year period. Southwest Kansas had areas of greater than 50 feet decline in water levels from the predevelopment to 2003. Pumping of air is a major problem that is readily observed. It is the gradual decline in the water table and the decrease in irrigation uniformity that is not as easily observed. The effect of these changes are discussed and examples presented of the reduction in irrigation depth and decrease in irrigation uniformity.