A canal carries a discharge of 20 m³ /s at a depth of 1.5 m and has its bed 3.5 m higher than the bed of a drainage it has to cross. If the drainage has a high flood depth of 2.5 m, then the type of cross drainage works appropriate to this site is
- AAqueductCorrect
- BSyphon aqueduct
- CSyphon
- DSuper Passage
Solution
Concept
Aqueduct versus syphon
Step-by-step solution
1. Canal bed is 3.5 m above the drainage bed. 2. HFL of drainage is 2.5 m, below the canal bed, so the drainage passes freely under the canal: aqueduct.
Explanation
When drainage HFL is below the canal trough, an aqueduct is suitable.
Why the other options are wrong
Syphon types need the HFL above the canal bed.
Shortcut
Bed of canal above HFL → aqueduct.
Correct answer: A) Aqueduct