This document discusses different types of canal falls, which are structures constructed to lower the bed level of a canal. It describes seven common types of falls: ogee fall, rapid fall, trapezoidal fall, stepped fall, montague fall, vertical drop fall, and straight glacis fall. Each type is suitable for different conditions depending on factors like the height of fall, discharge, site topography, and cost. The document provides details on the design and suitability of each type of canal fall.

1. By Gnana Prakash P
315126508064

2.  Introduction
 Necessity
 Types of Falls :
 Conclusion
 References
 Ogee fall
 Rapid fall
 Trapezoidal fall
 Well type fall
 Vertical Drop fall
 Stepped Type Fall
 Montague Fall

3. Canal : An artificial waterway constructed to allow
the passage of boats or ships or to convey
water for irrigation provided with
permissible slope.
Canal Fall : A Structure constructed to achieve the
object of lowering the bed level of a
canal suitably

4.  Canals are constructed with some
permissible bed slopes so that there is no
silting in the canal bed
 Ground surface may be steep and sometimes
it may be very irregular with abrupt change
of grade.

5. Necessity:When the slope of the ground suddenly
changes to steeper slope.

6.  When the slope of the ground is more or less
uniform and the slope is greater than the
permissible bed slope of canal

7.  The height of fall of water
 The discharge passing over the fall
 Topography of site location
 Type of soil in upstream and downstream of
structure
 Economy

8.  Ogee fall
 Rapid fall
 Trapezoidal fall
 Stepped fall
 Montague fall
 Vertical drop fall
 Straight Glacis fall

9.  an ogee curve (a combination of convex
curve and concave curve) is provided for
carrying the canal water from higher level to
lower level.

10. It is limited to low depths
Due to smooth transition, velocity of flow is not
reduced since it may cause erosion in down stream
It has high discharging efficiency

11.  It is suitable when the slope of the natural
ground surface is even and long.
 It consists of a gentle longitudinal slope
which varies from 1 in 10 to 1 in 20.

12.  These are expensive compared to others
 Commonly used at West Yamuna canal

13.  In this the body wall consists of several
trapezoidal notches between the side piers
and the intermediate piers.
 The sills of the notches are kept at the
upstream bed level of the canal.

14. It may of Singular or number of openings
constructed at high crested wall providing
smooth entrance to downstream
With this the depth to discharge value are
less affected
These are quite common and economical

15.  It consists of a series of vertical drops in the form
of steps.

16.  This steps is suitable in places where sloping
ground is very long and require a long gentle
slope to connect the higher bed level at u/s with
lower bed level at d/s.

17.  In this Canal u/s bed is on the level of upstream
curtain wall, canal u/s bed level is below the crest
of curtain wall. In both the cases, a cistern is
formed to act as water cushion.

18.  Easy to construct and economical
 Losses may be high in case of higher depths
 For discharges upto 15cumecs vertical drop
fall is used

19.  It consists of a straight glacis provided with a
crest wall. For dissipation of energy of flowing
water, a water cushion is provided

20.  Generally sloping will be 2:1
 These have Good performance
 Suitable upto 60cumecs and drop of 1.5m

21.  In the straight steep type profile, energy
dissipation is not complete. Therefore, montague
developed this type of profile where energy
dissipation takes place

22.  For flumed conditions vertical type is not suitable
because effective dissipation is difficult, at there
Straight galcis falls are used
 When full energy dissipation does not take place on
structure, baffle wall is used
 For un-flumed conditions the baffle design is well
suited

23.  Talwani, B.S. et al (1952).Canal Falls. Journal
of Irrigation & Power, April, 269–288.
 Naib, S.K.A. (1966). Hydraulic Design of
Energy Dissipators. Water & Water
Engineering, May, Vol. 70, 191–193 and
(1967), Vol. 71, 336