Hydraulic structures are constructed across the river to retain water at upstream side so that it can be used in future for different purposes. The basic purpose of hydraulic structure is to store water in reservoir for generating electricity, for irrigation and for general needs by humans. There are different types of hydraulic structures constructed according to needs and financial aspects.
In this short article the difference between weir, barrage and dam shall be discussed.
Weir :
The Weir is an impervious barrier constructed across the river to raise water level on the upstream side, such that the water level rises upto the required height and the surplus water is allowed to flow over the weir.
Weir is generally constructed across the inundation river.
Barrage :
The Barrage is an upgradation of Weir in which adjustable gates are installed over the weir to maintain the water surface at different levels at different times. The water level is adjusted by operating adjustable gates. These gates are operated by cables.
Dam :
The Dam is a high impervious structure constructed across the river to form deep storage reservoir. The Dam is designed such that the water level remains under summit (i.e. surplus water is not allowed to flow over the dam). The water is allowed to flow through spillways provided at some designed levels.
