Field Study on Irrigation Delivery Performance

Farmers who receive water from irrigation districts prefer deliveries that are flexible but accurate in frequency, rate, and duration. To study how well an irrigation district was able to match deliveries to farmers' orders and to account for deliveries, water deliveries along two monitored lateral canals were compared to the orders and bills for those events. The data showed that farmers complied with the official ordering policy about half the time, and were more likely to follow the policy during the late summer than during the spring. No corresponding bill existed for 16.8% of deliveries. Deliveries occurred on average about a half day later than ordered by farmers, and 72% occurred within one day of the ordered date, which is within the latitude allowed under district policy. One‐third of the deliveries ordered within the official policy had a mean flow rate plus or minus 10% of that ordered; 87% had durations plus or minus 10% of that ordered. For 43% of deliveries that had corresponding bills, billings were for flow rates within 10% of the measured mean; 50% were billed for durations within 10% of measured values. Further research is needed to determine the economic and environmental effects of inaccurate deliveries, and thus determine incentives to improve performance.