1. Reducing percolation from irrigation channel.
2. Reducing percolation from water course and field.
3. Encouraging economical use of water.
4. Increasing outflow from ground water reserves.

HOW CANAL ALIGNMENT SHOULD BE DONE?

1. It should serve the entire area proposed to be irrigated.
2. Cost of construction including cross drainage works should be inimized.
3. A shorter length pf canal ensures less loss of head due to friction and smaller loss of discharge due to seepage and evaporation, so that additional area may be brought under cultivation.
4. A canal may be aligned as acontour canal, a ide slope canal or a ridge canal according to the type of terrain and culturable area.