This document discusses balancing depth in canal design, canal lining, and design principles for lined canals. It defines balancing depth as the depth where the amount of cut material equals the amount of fill material. It lists advantages of canal lining such as reducing seepage losses and maintenance costs. Design principles for lined canals include selecting economical cross-sectional shapes based on discharge and using side slopes of 1:1 or 1.25:1 that are stable for the soil. Input data includes discharge, roughness, slopes, and maximum velocity, and output data includes breadth and depth calculated using Manning's equation.

1. RAMANUJ JALDHARIV Sem

2. CANAL IRRIGATION & DIVERSION HEAD
WORK

3. Difference B/W Kennedy’s & Lacey’s
Theory

4. Balancing Depth
 A canal section will be economical when the
earth work involved at a particular section has
an equal amount of cut and fill.
 If the amount of cut is equal to the amount of
fill, it has to be paid for one only.
 More so, the necessity of a borrow pit or soil
bank is entirely avoided.
 For a given cross section there is always only
one depth of cutting for which the cutting and
filling will be equal. The depth is known as
balancing depth.

5. Lined Canal
 Lined canal means that canal is made of some
material (such as brick, brick tile or cement
concrete) which can block seepage of water
into soil.
 In other words, make canal surface as rigid
boundary.

6. NECESSITY OF CANAL LINING
•To minimize seepage losses in canal
•To increase the discharge in canal section by
increasing the velocity
•To prevent the erosion of bed and sides of canals
•To reduce maintenance of canals
•To protect the command area
•To protect the canal from the damage by flood

7. ADVANTAGES OF CANAL LINING
• Reduces the loss of water due to seepage.
• Increases the duty of water.
• Controls the water logging.
• Provides the smooth surface & hence velocity of flow gets
increased.
• Due to increased velocity, discharge capacity of a canal is also
Increased.
• As a result, evaporation losses will be reduced.
• Eliminates the effect of scouring in the canal bed.
• Decreases the possibility of silting in the canal bed.
• Provides the stable section of the canal.
• Reduces the requirement of land width for the canal.
• Reduces the maintenance cost for the canal.

8. DISADVANTAGES OF CANAL
LINING
• High initial cost
• Difficulty for repairing the damaged section of
lining
• Long time to complete lining work
• Changes in c/s are not easily possible

9. Design Principles of lined canal
1. Geometrical cross section of lined canal should be
economical and at the same time it should be functionally
efficient.
2. For Q ≤ 100 Cumec: Triangular section with sloping sides.
For Q > 100 Cumec [i.e, trapezoidal channel with rounded
bottom corners].
3. Side slope(n or θ) = 1 : 1
Side slope (n or θ)= 1.25:1
4. The side slope is selected in such away that it nearly equals
the angle of response of the soil in the subgrade.

10. Design Principles of lined canal
5. Input data will be Discharge Q, Rugosity coefficient (N)
side slope θ, longitudinal slope S & Maximum
permissible velocity.
6. Output data will be Breadth (B) and Depth (d).
7. From the known values of v, n and s with the help of
Manning’s equation R can be obtained
V=R2/3S1/2/N

11. Design Principles of lined canal
8. Area of cross section A is given by
Q=AV A = Q/V
9. Wetted perimeter is given by
R= A/P P = R/A
10. For triangular channel section with rounded corners
A = d2(θ + cot θ)
P = 2d(θ + cot θ)
d, θ can be obtained
For trapezoidal channel with rounded corners
A = Bd + d2[θ + cot θ]
P = B + 2d[θ+cot θ]

12. Any Query……???