flap gate

A flap gate is a type of gate used in hydraulic engineering that is hinged at the top and opens only one way. It is designed to automatically close when the flow of water reverses in a channel.1

Gates in hydraulic engineering are movable barriers used to control the passage of fluids through channels or sluices. They are crucial for managing water flow from reservoirs, around dams, and through spillways. Different types of gates exist, including leaf gates that swing or slide, radial gates that lift clear of the water, and rolling gates that move up an inclined surface. Floodgates, specifically, are used in conjunction with dams to manage water release over spillways, acting as a safety feature to prevent erosion and potential dam failure.23