Back to spillwaysSpillways & Outlets - Scour
A Scour and a water supply pipe
running through a tunnel under a dam
The scour is an outlet pipe or tunnel that runs through the bottom of the dam. It is usually large because of its uses.
The scour can be used in an emergency, for example, when a dam is damaged and poses a threat of imminent collapse. It can be opened to let water out of the reservoir very quickly.