In this case of designing a sarda type fall fluming is not possible, refore length of crest is kept equal to bed width of canal.

When ground has a steep slope heavy earth filling is required to construct canal with a flatter bed slope. The difference between natural slope and designed bed slope is adjusted by constructing vertical falls or drops in canal at a suitable interval.

By considering commanded area of a branch canal or a distributary canal location for falls is decided. The procedure is to fix FSL needed at head of off taking channels and outlets. Thus FSL can be marked at all commanded points and hence deciding appropriate locations for falls in canal FSL and refore in canal beds.

When discharge level is under 14 cumecs rectangular crest is used. The top width is 0.55?d and base width is (h+d)/G (G = 2 for masonry). If discharge is more than 14 cumecs n trapezoidal crest is used. Top width is equal to 0.55\(\sqrt{(H+d)}\) with upstream slope is 1: 3 and downstream slope is 1 : 8.

In this type of fall energy dissipation is incomplete on a straight glacis due to vertical component of velocity remains unaffected. So, refore due to this reason straight glacis is replaced by a parabolic curve known as Montague profile. This curved glacis is difficult to construct and refore is costlier. Hence it is not adopted in India.

The diameter of inlet well is kept as 1.5 times value of X.
Given, X = 1.05 and Y = 1.88
Diameter = 1.5 x 1.05 = 1.575 m.

Since idea of construction of falls various types of falls have been designed. Some important falls are ogee falls, rapids, trapezoidal notch falls, simple vertical drop type and sarda type falls, straight glacis falls, Montague type falls and inglis falls.

In this fall notches could be designed to maintain normal water depth in upstream channel at any two discharges, as intermediate values do not vary much. Therefore depth discharge relationship of channel is not affected by introduction of fall.

In case of branch canals and distributary canals, procedure is to mark FSL required on L-section of canal. It is done so as to cover all commanded points that decide suitable locations for fall in canal FSL and in canal beds.

The thickness of notch pier should not less than half of water depth and even it can be more when pier has to carry a superstructure.