What is the difference between Dam, Weir and Barrage?

A barrage and a dam may appear to be the same thing at first glance. Both are used to control the water level in large bodies of water. They are, however, constructed and used in very different ways. We have put together some quick facts about the difference between a dam and a barrage, as well as information about the world’s largest dam. Can you figure out which country it belongs to?

What is the difference between Dam, Weir and Barrage?

Difference Between Dam Weir and Barrage – Dams, weirs and barrages all are types of headworks used to increase the head of water on the upstream side. There is confusion between these terminologies which are explained in this article.

Weir or Reservoir

A weir is a diversion headwork constructed across a river to raise the water level on the upstream side. Like Barrage its main aim to divert water as it does not have a storage reservoir. The water is raised up to the required height and the water then flows over the weir. In a weir the water overflows the weir, In Barrages, water flows through adjustable gates. Weirs have traditionally been used to create mill ponds. They are also used to prevent flooding, measure discharge, and help render a river navigable.

The term “reservoir” refers to a man-made lake created by a dam that holds back water and is primarily used for storage.

The Indira Sagar reservoir in Madhya Pradesh is the country’s largest.

What is a Barrage?

A barrage is a type of dam, but instead of being a massive concrete wall that prevents water from flowing through it, it is a series of gates.

The amount of water that passes through these gates is directly controlled by opening and closing these gates. The use of a barrage rather than a dam allows the flow of water to be maintained for its intended purpose, such as irrigation of nearby cities, towns, or farmlands. Unlike a dam, the amount of water stored behind a barrage is determined by the height of the gates rather than the entire wall. Because the gates can be easily manipulated, the flow and level of water can be easily monitored.

When water does not need to be stored but rather diverted, a barrage is built. As a result, the barrage is usually constructed across a flat, slow-moving river. Unlike a dam, which raises the water level nearly to the height of the structure, a barrage only raises the water level by a few feet. Because a barrage can increase the depth of a river by a few feet, this is also useful for navigation.

In Short, A Barrage is a diversion headwork. its main aim is to divert the flow of river it does not have a storage reservoir on its upstream side. The water is elevated only to a few feet. The main difference from the wear is that it has adjustable gates installed on top of it. The water level can be maintained using these gates.

What is a Dam?

A dam creates a large water reservoir that can be stored and used later. Irrigation, water supply, and even electricity generation are examples of these applications. A dam is usually an impressive engineering feat, as the sheer height of the structure prevents water from flowing up and over it. A dam, unlike a barrage, is built solely to store water and raise the level of water contained within it.

A dam is designed with multiple spillways that allow excess water to flow into the river below. When the reservoir or lake reaches the dam’s top, this prevents the dam from being overtaken.

Dams, like barrages, have gates, but the gates and sluices are located at the top of the dam to prevent flooding and spillage.

A Dam, on the other hand, is a storage headwork so the main aim of the dam is to create a storage reservoir on the upstream of the dam. Dams are mostly multipurpose projects used for Irrigation, hydroelectric power, Flood control, recreation etc.

Difference between Dam and Barrage

Sr. No.DifferenceDamBarrage
1Storage at upstream sideMust haveNot have storage
2Gatesat the top of the intake structureat the entire height of the structure.
3.PurposeFlood control, hydropower, irrigation, water supply, recreationJust to divert river water
4.PopularityUse throughout the worldMostly constructed in East, Iran, Pakistan and India.

Er. Mukesh Kumar

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Er. Mukesh Kumar is Editor in Chief and Co-Funder at ProCivilEngineer.com Civil Engineering Website. Mukesh Kumar is a Bachelor in Civil Engineering From MIT. He has work experience in Highway Construction, Bridge Construction, Railway Steel Girder work, Under box culvert construction, Retaining wall construction. He was a lecturer in a Engineering college for more than 6 years.

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