The release gate is designed to open automatically in the event of an extreme high flood level occurring to release surplus flood waters. Once the water level has receded to the bottom of the gate, the gate can be easily and quickly reinstated to its closed position to start impounding water in the dam.
This is a safety fuse gate to work in conjunction with the TOPS and crest gates.
This type of fuse gate, the Amanziflow release gate, does not detach from the spillway but is retained on the structure for immediate reinstatement. Specially designed water filled dampeners will prevent the release gate from damage when it opens.