Irrigation Water Delivery Performance

Abstract

A number of delivery sites within an irrigation district were monitored in order to determine the amount of variability in flow rate during each water delivery. The coefficient of variation (CV) of instantaneous (1/2 hour) flow rate values averaged for each turnout ranged from 0.04–0.29. CV was related to the location of the site within the delivery system. Time of year, flow rate, and crops grown did not appear to affect CV. On‐farm water use is affected by the level of delivery flexibility and the uniformity of water deliveries. Upgrading of farm irrigation systems may require improvements in delivery flexibility and uniformity. However, increasing the delivery flexibility may result in less uniform deliveries, which may also reduce the operational conveyance efficiency of the delivery system unless the system is also upgraded. Improving the overall water use within an existing irrigation project will often require improvements in farm water management, delivery control, and canal system management.