Plunge pools are economic means to dissipate hydraulic energy of high speed flows. Plunge pools are
usually at the end of either spillways or bottom outlets. The flood discharge is directed into an air water
jet and travels through the atmosphere a
nd eventually strikes the plunge pool in which the hydraulic
energy is dissipated. Many scour problems result from those free falling jets downstream of the hydraulic
structures. In recent years various researchers have investigated scour problems downstream hydraulic
structure such as spillways and bottom outlets and numbers of empirical and semi-empirical equations
have been developed for predicting the length and depth of scour hole resulting from the jet.