Changing Water Sources in Agriculture: Impacts in the Pinal AMA

 

Thomas A. Whipple and C.L. Winter

Department of Hydrology and Atmospheric Sciences

The University of Arizona

As the amount of excess CAP water available to farmers shrinks and the possibility of a shortage declaration on the Colorado looms, farmers in Central Arizona face a loss of Central Arizona Project water. Many will have the ability to replace CAP water by pumping groundwater, which will have an impact on reductions in groundwater overdraft in the region. This study looks at how the economics of farming cotton in the Pinal Active Management Area are affected under different water sources. Crop-water production functions for cotton in the Pinal AMA are estimated using Aquacrop and the profit maximizing level of water applied is calculated under different scenarios.