Question

Weir / barrage classified according to use is known as

• A. Storage dam
• B. Diversion dam
• C. Detention dam
• D. Check dam

Hint:

Remember the primary function of different river structures:
- Dam (large) $\rightarrow$ Storage (creates a reservoir).
- Weir / Barrage $\rightarrow$ Diversion (raises water level to feed a canal).
- Detention Dam $\rightarrow$ Flood Control (temporary storage).

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks for the functional classification of a weir or barrage.

Step 2: Detailed Explanation:
Dams, weirs, and barrages are hydraulic structures built across rivers. They are classified based on their primary purpose or use.

• (B) Diversion Dam/Weir/Barrage: The primary purpose of a weir or a barrage is not to store large quantities of water for a long time, but to raise the water level in the river just enough to

divert a portion of the river's flow into an off-taking canal for irrigation, water supply, etc. This is their main use.

• (A) Storage Dam: This is a large dam built to impound water and create a large reservoir. Its primary purpose is long-term storage of water for purposes like irrigation, hydropower, flood control, and water supply during dry seasons.

• (C) Detention Dam: This type of dam is built specifically for flood control. It temporarily stores (detains) floodwater and releases it at a controlled rate to prevent downstream flooding. The reservoir is normally empty.

• (D) Check Dam: A small dam, typically built in a small channel or gully, to reduce flow velocity, control soil erosion, and promote groundwater recharge.


The term "weir" or "barrage" is most directly associated with the function of diversion.

Step 3: Final Answer:
A weir or barrage, when classified according to its primary use, is known as a diversion structure or diversion dam.