Canal lining and its advantages: 
It is process of covering or lining the earthen surfaces of a canal with stable, non-erodible lining surface such as concrete, tiles, asphalt etc. 
Some of the key advantages of lining a canal are the following:
 Seepage Control: As the earthen surfaces are lined, so the seepage loss in the lined canal reduces considerably and stops the uncontrolled seepage which takes place in an unlined canal. This in turn saves huge amount of water which can be used for irrigation purposes. 
Constant (flatter) Hydraulic Gradient: Because of minimal seepage and infiltration head loss is almost constant along the length. 
 Prevention of Water Logging: In case of unlined canals, due to uncontrolled seepage water table often can rise to ground level leading to water logging. By lining canals water logging and subsequent increment in salinity can be prevented. 
Increased Canal Capacity(Q): As the surfaces are lined and smooth, so the frictional resistance is considerably less in case of lined canals. Less frictional

resistance results in increased flow of water per unit time which leads to more canal capacity. 
 Reduction in Maintenance Cost: Lining of canal may incur huge capital cost but the maintenance cost reduces substantially. The maintenance cost due to periodic silt removal, periodic removal of weeds and water plants and maintenance cost for minor repairs are substantially reduced by lining canals