2. Diversion Headworks
❖Any hydraulic structure which supplies mostly silt free water with certain
minimum head into the off-taking canal is called a headwork.
3. Diversion Headworks
Headworks may be divided into two major classes:
1) Storage Headwork: It comprises the construction of a dam across the river. It
stores water during the period of excess supplies in the river and releases it
when demand exceeds available supply.
2) Diversion Headwork: It serves to divert the required supply into the canal
from the river. The objectives of this type of headworks are as following.
✓ It raises the water level in the river so that the commanded area can be
increased.
✓ It regulates the intake of water into the canal.
✓ It controls the silt entry into the canal.
✓ It reduces fluctuations in the level of supply in the river.
6. Components of Diversion Headworks
The components of diversion headworks are:
❖ Weir or barrage
❖ Canal head regulator
❖ Divide Wall
❖ Fish Ladder
❖ Scouring Sluices Under sluices
❖ Silt excluder
❖ Silt ejector.
❖ Marginal embankment or dikes
❖ Guide bank
❖ Silt pocket or trap.
8. Weir or Barrage
Weir is a solid obstruction placed across the
river. Its main function is to raise the water
level so that water can be diverted from canal
to crop field due to head difference.
Barrage is practically a low weir with an
adjustable gate over this low weir. Heading
up of water is affected by gate.