A barrage is 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 the structure, and thus regulate and stabilize river water elevation upstream for use in irrigation and other systems. The gates are set between flanking piers which are responsible for supporting the water load of the pool created. While the term barrage is borrowed from the French word meaning a dam generally, its usage for such a structure in English is chiefly in Pakistan, India, Egypt, Iraq, and other countries in the Middle East.
According to the World Commission on Dams, a key difference between a barrage and a dam is that a dam is built for water storage in a reservoir, which raises the level of water significantly. A barrage is built for diverting water, and raises the water level only a few feet; they are generally built on flat terrain across wide, often meandering rivers. Similar distinctions are used in Egypt, where it is noted: "In this system a "dam" is a structure that forms a reservoir for the storage of water during the annual flood period of the Nile in order to supplement the natural flow of the river during the low-water period; a "barrage" merely raises the river or canal level, when necessary, to the height required for adequate flow into the canals that take off above it. Barrages are usually larger than the headworks of irrigation and navigation canals, with which they are associated.
- V. J. Zipparro, Hans Hasen, Davis' Handbook of Applied Hydraulics, 4th Edition, p.12.1. Mcgraw-Hill, 1992. ISBN 978-0070730021
- Salman, Salman M. A.; Uprety, Kishor (2002). Conflict and cooperation on South Asia's international rivers: a legal perspective. World Bank Publications. p. 135. ISBN 978-0-8213-5352-3. Retrieved 27 April 2011.
- Raye R. Platt, Mohammed Bahy Hefny, Egypt: A Compendium, p.198, American Geographical Society, 1958. Retrieved 2014-12-03 – via Questia (subscription required)
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