Flood Chute

a hydraulic-engineering facility in the form of an open, lined channel or trough for transferring a stream of water at a high velocity from the upper part of an aqueduct (reservoir) to a lower part. Flood chutes are built in hydraulic-engineering projects to let flood waters pass into diversionary spillway channels at hydroelectric power plants or into irrigation and drainage canals; they also are used as fish and lumber passages. They consist of an entry section, which is usually constructed in the form of a wide ramp or spillway having a rectangular or trapezoidal cross section and a substantial longitudinal slope of the bottom, and a tail section in the form of a stilling pit, which is replaced by a baffle to deflect the stream when there is a rocky base. Flood chutes may be made of concrete or reinforced concrete; less frequently, of wood and stone.