Canal lining has some advantages and some disadvantages which are as follows:
Advantages of Canal Lining
Following are the advantages of canal lining:
1. Seepage Control
Canal lining helps to prevent water loss due to seepage. Heavy seepage losses in canals would require a large reservoir and a bigger dam to be built. Therefore, preventing seepage by lining would decrease their impounding capacity, thus reducing the construction costs of these works.
2. Prevention of Waterlogging
In simple words, the rising of the water table near to the ground surface is known as waterlogging. The water table in the surrounding field of the canal rises near to the ground surface level because of the continuous seepage through the unlined canal.
As a result, it brings up the harmful salts near the ground surface, which makes the land unsuitable for cultivation. Thus, the lining of the canal prevent waterlogging, and it helps to increase food production.
3. Increase in Commanded Area
Lined canal reduces the evaporation loss as well as seepage loss. Which saves more water for irrigation. Additional areas may be brought under irrigation from the water saved by the lining.
4. Prevent Weed Growth
Unlined canal sides and bed are very favourable for the growth of weeds. It reduces the velocity of the water flow through the canal. Hence, by providing lining, growth of weeds can be prevented.
- High velocity prevents silting of the canal.
- The lining makes the bank more stable.
Disadvantages of Canal Lining
Following are the disadvantages of canal lining:
1. It requires a very heavy initial expenditure.
2. When lining gets old, cracks usually develop. It is very hard to check leakage through cracks.
3. The portion of the lining joints always creates problems.
4. The outlet shifting process is very difficult.