An economic supply function for the diversion of irrigation water to Tucson

Abstract

Water is a severely limited resource to the City of Tucson. Additional water imported from outside the city is one way to mitigate the shortage. One alternative source of such water is the diversion of irrigation water to the city from nearby farming areas. The direct cost of such water includes buying the land on which it is now used and installing the necessary works to develop and deliver it. Budgets of such costs were developed in units of 10 and 20 million gallons per day and the direct cost per acre-foot determined. Irrigated agriculture is part of the economic base of the Tucson economy. Its elimination by diversion of the water upon which it depends will reduce the city's economy and is an indirect cost of such water. Estimates were made of the magnitude of such indirect economic costs and were added to the direct pumping and delivery costs. These two costs constitute the total economic cost of diverting irrigation water to municipal use. The increase in this cost as increasing quantities of water are acquired constitutes the supply schedule for increments of water diverted from irrigation to municipal and industrial use in Tucson.