Regulation works are structures constructed to regulate water flow in canals. The main types are head regulators, cross regulators, canal escapes, and canal outlets. Head regulators control water entry into off-taking channels from parent channels. Cross regulators are located downstream of off-takes and help control water levels and closures for repairs. Canal outlets connect distribution channels to field channels and supply water to irrigation fields at regulated discharges.

1. Canal Regulation Works
 Any structure constructed to regulate the discharge, full
supply level or velocity in a canal is known as a regulation
work.
 Such a structure is necessary for the effieient working and
safety of an irrigation channel.
 The various regulation works may be categorised as under:
 Canal fall
 Head regulator
 Cross regulator
 Canal escape
 Canal outlet

3. Head Regulator
 Regulators Constructed at the off taking point are
called head regulators.
 When it is constructed at the head of main canal it is
known as canal head regulator.
 When it is constructed at the head of distributary, it is
called distributary head regulator.

4. Head Regulator
Function:
 They regulate or control the supply of water to
the offtaking channel from the parent channel
 They control the entry of silt in the offtaking
channel.
 They serve as meter for measuring the discharge
entering into the offtaking canal
 They help in shutting off the supplies when not
needed in the offtaking channel is required to be
closed for repairs

5. Head Regulator
Construction:
 The components of head regulator depends
upon the size of canal and location of head
regulator.
 For large canals head regulators are flumed to
facilitate the measurement of discharge.

6. Cross Regulator
 A Regulator Constructed in the main canal or parent
canal downstream of an off take canal is called cross-
regulator.
 It is generally constructed at a distance of 9 to 12 km
along the main canal and 6 to 10 km along branch
canal.

7. Functions of Cross Regulator
 Usually a bridges on the cross regulator, which
provides a means of Communication.
 During the periods of low Discharge, the cross
regulator raises water level on the u/s so that the
offtaking channel can takes its full supply.
 Helps in closing the supply to the d/s of the parent
channel, for the purpose of repairs.
 Used to control the drawdown when the subsoil
water levels are high to ensure safety of canal lining.

8. Canal regulators

9. Canal regulators

10. Cross Regulator

11. Head Regulator

12. Canal Outlet/modules
 A canal outlet or a module is a small structure
which admits water from the distributing channel to a
water course of field channel.
 An outlet is a sort of head regulator for the field channel
delivering water to the irrigation fields.
 It acts as a connecting link between the system manager
and the farmers.
 The discharge through an outlet is usually not less than
0.03 cumec & not more than 0.085 cumec.

13. Requirements of good Outlet
 It should be simple in design ,construction and
maintenance.
 It should be quite strong and durable.
 It should not be easily tampered with by the cultivators, but
if tampered with it should be easily detected
 It should be worked efficiently with a small working load.
 It should not be expensive.
 It design should be such that it can be easily constructed by
the local workers.

14. Types of Outlets
Outlets may be classified under the following
there heads:
 Non-modular outlet
 Semi-module of Flexible Module
 Rigid Module

15. Non-Modular Outlets
 Non-modular Outlets are those through which
the discharge depends upon the head
difference between the distributary and the
water course.
Common examples are:
(i) Open sluice
(ii) Drowned pipe outlet

16. Non-Modular Outlets
 Non-modular modules

17. Semi-modular outlets
 The discharge through these outlets depend on the water
level of the distributing channel but is independent of the
water level in the watercourse so long as the minimum
working head required for their working is available.
Types of Semi-modules
 Pipe Outlet Discharging Freely into Air
 Venturi Flume Oulet or Kennedy Guage Outlet
 Open Flume Outlet
 Adjustable Orifice Semi-module

18. Semi-Modules or Flexible modules
 Due to construction, a super-critical velocity is ensured in
the throat and thereby allowing the formation of a jump in
the expanding flume.
 The formation of hydraulic jump makes the outlet discharge
independent of the water level in water course, thus making
it a semi module.
 Semi-modules or flexible modules are those through which
the discharge is independent of the water level of the water
course but depends only upon the water level of the
distributary so long as a minimum working head is available.

19. Semi-Modules or Flexible modules

20. Rigid Modules or Modular Outlets
 Rigid modules or modular outlets are those
through which discharge is constant and fixed
within limits, irrespective of the fluctuations of
the water levels of either the distributary or of
the water course or both.
Types of Rigid Modules
 Gibb’s Module
 Khanna’s Rigid Module
 Foote Module

21. Gibb’s Module

22. GIBB’S MODULE
 DESIGNED BY A.S.GIBB{Punjab Irrigation Dept.}
 Q Varies b/w 0.03 to 0.45 cumec
 For lower value of Q b/w 1 to 3 cusecs, it is
economical in RCC structure
 For higher value of Q , it is constructed in brick
masonry.