Economic incentives reduce irrigation deliveries and drain water volume

This paper describes the application of an economic incentive program to achieve water quality objectives by motivating improvements in farm-level water management practices. The program includes farm-specific water allotments, tiered water pricing, and low-interest loans for purchasing irrigation equipment. The implementation of this program in a California water district has resulted in significant reductions in irrigation deliveries and drain water volume. Since the program was implemented, average irrigation depths have declined by 25% on cotton fields, 9% on tomatoes, 10% on cantaloupes, 30% on seed alfalfa, and 29% on grain fields. The average volume of drain water collected each year in subsurface drainage systems has declined from 4.8 million m³ during 1986 through 1989 to 2.6 million m³ during 1990 through 1993. These results confirm that economic incentives can be effective in generating improvements in water quality.