Canal Cross section | Irrigation Engineering in Hindi | Water Resources | GATE ESE IES SSC JE
CROSS SECTION OFCANAL * A typical and most desirable section of a canal is partly in cutting and partly in filling and aims at balancing the quantity of earthwork. * Berm is a narrow strip of land at the ground level between the inner toe and top edge of the cutting. * Counter berm (or back berm) is provided on the outside of the canal bank to contain the hydraulic gradient line within the bank. * Minimum free board required in any canal is 0.5 m. With increase in discharge, minimum free board specified is increased for a canal with discharge more than 30 cumec free board of 0.90 m is enough. Lining of Canal * Advantages of lining a canal are 1. Seepage is controlled 2. Waterlogging can be prevented 3. Channel capacity is increased 4. Command area is increased 5. Maintenance cost is reduced 6. Danger of flood is eliminated. * Maximum permissible velocities in different types of lining are: 1. Cement concrete lining – 2.0 to 2.5 m/sec 2. Burnt clay tile lining – 1.8 m/sec 3. Boulder lin...