There is some confusion around the difference between weirs and barrages, more particularly how they fit in the spectrum of the dams category as a whole. Effectively, both weirs and barrages are what’s called headworks that are used to increase the head of water on the upstream side. In this article, you will learn the differences between a weir and barrage.
A weir is simply a concrete or masonry structure that is built through an open channel, for instance, a river. In most cases, it is built to control water flow, measure the discharge, prevent flooding, and make rivers navigable. It can be built with different materials such as wood, concrete, or a mixture of rocks, gravel, and boulders depending on age and purpose. In a weir, the water overflows the weir, but in a dam, the water overflows through a special place called a spillway.
On the other hand, a barrage is a concrete structure that consists of a series of large gates that can be opened or closed to control the amount of water that flows through them. This allows the structure to adjust and stabilize the elevation of the upstream water for irrigation and other systems. The valves are positioned between the pillars that have the task of supporting the water load of the pool created.