Canal lining is the impervious layer which protects the bed and sides of the canal. Lining is generally a construction of a thin 2.5 to 15 cm thick layer of lining material, generally RCC or CC bricks, stones etc.
Canal lining an irrigation canal or channel needs extra amount to be spent on the construction but in the long run, this lining which helps to control the seepage through the banks and bed and this extra water made available through the process of lining can justify the extra expenses made on the lining of the channel.
In the canal system while water flows towards an irrigable area it may lose due to seepage that means crops will not get the required quantity of water. Which affects the yield of crops.
Therefore it is necessary to provide an impervious layer on the bed and side of the canal to minimize losses.
Advantages of canal lining:
- Reduction in losses due to seepage: Lining prevents seepage so finally more than can be irrigated by the same quantity of water and valuable water is saved.
- Prevention of water logging: Seepage is the main cause of water logging if the canal is lined the seepage is reduced and thus helps in protection from water logging.
- Low maintenance Cost: The maintenance of lined canal is less as compared to unlined canal
- Prevention of weed growth: lining prevents the growth of weeds.
- Steeper bed slope can be provided: Hard surface lining can sustain higher velocities, that means steeper bed slope can be provided
- Less breaches : In lined canal possibility of breaching is less as section due to lining is more stable and strong.
- High initial cost: The initial cost of a lined canal is high.
- Leakage from joint: There might be chances of leakage through joint.
- Difficult to repair: If it is damaged it is difficult to repair.
- Difficult to shift outlet: As lining is strong it is difficult to shift outlet in later stage.
- In lined channels berms are not provided.
- The lining increases the initial cost of investment required for the construction of an irrigation channel.
- It goes very difficult to repair the damaged lining work
- These lined channels are without berm so the safely provided by berm for the traffic on the service road is absent.
Types of Canal lining:
- Cement / time concrete lining
- Cement mortar lining
- Stone masonry lining
- Brick lining
- Shotcrete lining
- Asphaltic lining
- Precast concrete block lining
- Sodium carbonate lining
Classification of lining
- Exposed and hard surface lining
- Buried membrane lining
- Earth lining