Bank Instability and Erosion Control Measures
Caving of bank is one of the principal reason of deterioration of river conditions. Bank protection therefore forms an integral part in the river training programme. Rivers passing through heavily populated areas require protection from erosion of valuable lands and properties. Similarly, protection against erosion means often saving the holdings from destruction. Banks located upstream and downstream of hydraualic structures such as weirs, barrages and bridges have to be protected depending on the direction and nature of current. Further, bank protection is needed for flood embankments which on breaching will cause disaster to the large areas protected by them. The basic premise of erosion control measures rests on maintaining an acceptable profile of the water course with permissible tolerances. Non-cohesive banks are subjected to surface erosion which results piecemeal loss of material over a period of time. Spur or spur systems alter bank line orientations by deflecting currents.