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.