A retarding reservoir for flood control is the one which is provided with
- Auncontrolled outlets and spillwayCorrect
- Buncontrolled outlets but controlled spillway
- Ccontrolled outlets but uncontrolled spillway
- Dcontrolled outlets and spillway
Solution
Concept
Flood control reservoirs
Step-by-step solution
1. A retarding reservoir has ungated (uncontrolled) outlets and an ungated spillway. 2. It attenuates the flood automatically.
Explanation
Both outlets and spillway are uncontrolled in a retarding reservoir.
Why the other options are wrong
Controlled outlets or spillway are features of detention reservoirs.
Shortcut
Retarding = no gates.
Correct answer: A) uncontrolled outlets and spillway