A barrage can refer to two different things: a type of low-head, diversion dam which consists of a number of large gates that can be opened or closed to control the amount of water passing through, allowing the structure to regulate and stabilize river water elevation); or a continuous firing on an area with large guns and tanks, usually in a military context.
In the context of a dam, a barrage is built for diverting water, and raises the water level by only a few feet. It is generally built on flat terrain across wide, often meandering rivers, and can be used to divert water for irrigation needs or limit the amount of water downstream). The gates in a barrage can be opened and closed to directly control the amount of water that passes through it, allowing the flow of water to be kept stable for its intended purpose, such as irrigation to nearby cities, towns, or farmlands. Unlike a dam, the water stored behind a barrage depends on the height of its gates and not the height of the entire wall.
