Spate irrigation is an ancient practice by which floodwater is diverted from its river bed and channelled to basins. Spate irrigation has evolved over the centuries and provided rural populations in arid and semi-arid regions with an ingenious way to manage their scarce water resources. It is different from conventional irrigation in many ways and therefore needs special skills and approaches that address the unpredictability and magnitude of spate floods and their high sediment load. The objective of this publication is to assist planners and practitioners in designing and managing spate irrigation projects looking at the hydrology, the engineering, the agronomy, the economics and local organisation and rules. It is designed to be both a practical guidance document and a source of information and examples, based on experience from across the world in places where spate irrigation is practised.