There is a considerable difference between dam and barrage and how they control flooding. A dam is constructed across a river to prevent flooding and perform a variety of other functions. On the other hand, a barrage is an old method of flood control.
Do you know dam and barrage both are human-made structures constructed across the river between river banks? But the fantastic thing is that both are different in how they operate.
The two primary structures are confusing and may look the same to a newbie.
But there’s much difference. So, here’s our take on the difference between a dam and a barrage.
What is a dam?
Diversion headworks or dam is a significant type of flood control structure. It is constructed across the river, with a spillway from the ground to the top for diverting water safely. Having a large lake containing a natural water flow of over twenty thousand gallons per minute allows people to benefit from such a massive structure.
A dam is a multi-purpose structure, and the people or community can get a lot of benefits from its construction. We use them for purposes like:
- Storage of water
- Irrigation purpose
- Hydroelectric power
- Flood control
What are a weir and a barrage?
Weir is an impenetrable structure. It is an obstruction build artificially across the stream throughout its width to raise water level upstream to check the flood, store water or measure discharge.
The simplest definition of a barrage would be – a gated weir is known as a barrage. That means that a barrage is an artificial obstruction constructed across the river’s flow that can regulate the river’s flow and divert the river water into the canal after raising the water to a slight elevation as needed for the irrigation of the catchment area of the channel.
How is a barrage different from a dam?
On the other hand, the dam is a waterproof obstruction built across the river’s flow to store water, generate electricity for aesthetic purpose and control floods.
Differences in function
The dam’s primary function is to create a water reservoir that will use for drinking purpose or with the help of the energy stored in the water; we can generate electricity.
In other words, we can say that dam are multi-purpose, like one purpose is water storage, electricity or power generation, aesthetic or artistic purpose.
On the other hand, the barrage has no such storage of water; So, you can’t say it as head raising headworks. The primary function is to regulate the flow of the river of water into the canals in the amount needed for agriculture use.
The word “barrage” is a French word having the meaning of “a dam”. This word was originated by two French who were employed in Egyptian Public works, which built Delta Barrage across Nile-Branches near north of Cairo.
British, after seeing them taken the word barrage and called similar structures with this name when constructed in British India. That is why the word “barrage” is still used for structures built in the Middle East, Iran, Pakistan and India.
Differences in structure
As we know, gates and sluices are constructed both in barrages and dams, so what’s the difference? The answer is; that in dams, the gates and channels are always at the top, having concrete structure beneath to retain a sufficient amount of water, and if required, the water is allowed to move through gates in the system called spillway.
Whereas in Barrages, the gates are from the top upto the bed of the river; thus, the barrage’s water storage capacity depends on the height of gates.
|1||Storage at upstream side||Must have||Not have storage|
|2||Gates||at the top of the intake structure||at the entire height of the structure.|
|3.||Purpose||Flood control, hydropower, irrigation, water supply, recreation||Just to divert river water|
|4.||Popularity||Use throughout the world||Mostly constructed in East, Iran, Pakistan and India.|
Undoubtedly, constructing both the structures, i.e. dam and barrage, allows for more efficient water use while preventing the runoff from the large river into smaller streams or rivers, or even into the groundwater.
However, constructing a dam or barrage would also have little effect on the amount of water sent to the underground water. The impact on wildlife and aquatic habitats would be massive.
The three gorges dam constructed has a considerable impact causing the loss of agricultural and industrial land and drastically altering the water supply. However, a diversion dam or other type of control would allow water to be diverted effectively and sustainably.