Open channels are very important to deliver water from main sources to laterals especially for developing countries. Production is subjective by the way that the water is scheduled, and this scheduling is subject to several irrigation constraints. In open channel projects, for instance, maximum discharge of the laterals and main channels, depending on the size of their dimensions and the water requirements for fields. The current paper shows how efficient water scheduling, regarding the delivering water from the main channel to laterals in consequent time slots, can be done by utilizing a genetic algorithm optimisation technique. This research is intended to be applied for scheduling the Shattulhilla River in Babylon City and has broad applications for open channel projects in Iraq. The obtained results clarify how the genetic algorithm optimisation modelling is a sophisticated tool which operators of irrigation projects could now utilize to timetable open channels of irrigation systems.