We applied models of groundwater withdrawal to four southwestern Kansas counties to evaluate the impact on aquifer levels, producer revenue under current and future crop prices, and irrigated acres for the next 50 years. Discount rates were applied, to convert future revenue to present dollars. Finally, a groundwater policy reducing irrigated acreage by ten percent was shown to reduce total water used in all four counties.
We found, reduced saturated thickness resulted in less water saving ability. A policy of acreage reduction is therefore most likely beneficial in counties possessing normal amounts of saturated thickness such as Finney, Grant, and Stevens counties. It is less effective in counties with low amounts of saturated thickness such as Hamilton.
We also found little difference in water use when comparing high and average crop prices, indicating well capacity is the limiting factor.
The ten percent acreage reduction scenario allows for revenue to remain more constant over the fifty-year study period than does the status quo scenario, as saturated thickness levels remain deep enough for more years to justify irrigation pumping.
Publication: Vestal, M., B. Guerrero, B. Golden, and L. Harkey. (2017). The Impact of Discount Rate and Price on Intertemporal Groundwater Models in Southwest Kansas. Journal of Water Resource and Protection 9, 745-759.