The size and complexity of collective irrigation scheme may vary largely but any type of irrigation system have the same function: delivering water to the farmers. The type of delivery schedule is a decision that should be made before designing the distribution network, although often the irrigation schedules are re-defined in response to changing conditions.

The quality of water-delivery service is evaluated in terms of equity, reliability, flexibility, adequacy and efficiency. The target of these indicators and the means to meet them change from scheme to scheme but the concept of service is applicable to all type of scheme.

A water delivery modality refers to the form by which the irrigation scheme characteristics and the distribution agency determine who will receive water, how much and when. The main delivery modalities are fixed rotation, arranged rotation and on-demand. The first modality is supply-driven and the last two are demand-driven. Each delivery modality is defined by: flow rate, irrigation frequency and irrigation delivery duration (ASCE, 1991, https://doi.org/10.1061/9780872627857).
All these water delivery concepts are included in this tool that consists in exercises in ExcelBooks. These exercises are being designed to facilitate the comprehension around water distribution elements and their implementation in schedules according to the delivery modality.

Skilled user may develop similar applications for specific real cases, and then applied it to improve schedules, operation and transparency.

Contact: luciano.mateos@ias.csic.es