A dam is constructed across the river and it is essential to make the working area dry or partially dry during construction of the dam. This chapter provides the technique of diversion of the river through an open channel or through a diversion tunnel by providing a coffer dam both at upstream and downstream of the dam.

Readers will gain a knowledge of construction of a diversion channel or tunnel as per site condition and a river can be diverted through this diversion tunnel to make the working area dry and facilitate construction activity. It educates readers about the procedure of construction of a coffer dam both in up and down stream and the type of construction materials and equipment required for the construction.