Abstract: Surface irrigation apparatus comprises a carriage movable along an irrigation canal. A dam is supported by the carriage in such a way that water flowing along the canal is incident upon the dam and is checked thereby and the carriage is pushed along the canal in the direction of flow. The carriage is provided with means for arresting its movement at desired positions along the canal. Preferably, the arresting means comprises on the carriage one or more arms which are releaseably engageable with stops on the canal although the arresting means could take the form of one or more brakes operated in accordance with the position of the carriage. The carriage also has means, such as syphon tubes, for transferring water from the canal to land to be irrigated.