Operational Plans and Performance in the Phitsanulok Irrigation System,Thailand

Key performance aspects of a 92 000 ha rice irrigation system in central Thailand are reviewed, with reference to water-distribution performance, agricultural performance and plan-implementation performance. Farmers have invested heavily in recent years in pumps, principally for access to shallow groundwater. This allows independent agricultural decision making by farm households. It is shown that tail-end farmers, who have the highest intensity of pumps, achieve the best agricultural performance. The performance in terms of canal water distribution and plan implementation is erratic. Absence of appropriate water-measurement facilities, insufficient information flows concerning water quantities and wide variations of farmer strategies seem to be significant reasons for these difficulties.