- A canal is an excavated path or a trench through which the from the reservoir flows to the cultivated lands by gravity.
- While fixing the alignment of the canal, it should be taken along the ridgeline so that it will command maximum area under irrigation such as canal is called watershed canal.
- As far as possible the canal should run along the centre line of the land to be cultivated.
- It should be excessive cutting and through favourable soil condition.
- Its path should not be taken without excessive cutting and embankment.
- It should cross minimum drainage lines. The cost of land acquisition should be as far as a minimum.