8.6. PROCEDURE FOR DESIGN OF IRRIGATION CHANNELS A canal system includes the main canal, branches, distributaries, and watercourses. Main canals, branches and distributaries are owned, constructed, controlled, and maintained by the government. Watercourses are owned, constructed, controlled, and maintained by the irrigators. Sometimes, the watercourses are constructed by the government agencies also. Their maintenance is, however, the responsibility of irrigators.
The main canal takes its supply from the source directly. The source may be either a river or a reservoir. There may be several branch canals and/or distributaries taking supplies from the main canal at various points along the main canal. A branch channel, similarly, feeds distributaries which take off at suitable locations along the branch channel. A distributary feeds watercourses which take water directly to the field. The discharge and size of irrigation channels progressively decrease from the main canal to the watercourses.