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Main canal
Main canal is the one which carries water directly from the river or diversion
head work. Branch canals are situated on either side of the main canal and
distributes water to the major distributary which carries discharge ranging from
¼ to 5 cumecs. Minor distributaries receive water from either branch canals or
major distributary and carry water of about ¼ cumecs. Water courses carries
water from the minors for irrigating farmers field. Field channels carry water of
smaller discharge from the water course to the farmers field.
Canal Alignment
Alignment of canal is very important for distribution of water effectively and
economically. The alignment of the canal should be such as to ensure (i) the
most economical way of distributing the water to the land, (ii) as high a
command as possible, and (iii) minimum number of cross drainage works
(Fig3.1).
Fig. 3.1 : Canal Alignment
(After Punmia et al, 1992)
According to alignment, the channels may be :
(1) Ridge canal
(2) Contour canal
(3) Side slope canal
