Question

During the survey of metro rail line, it was observed that a canal and drainage intersect at the almost same level while aligning the metro line from one point to another. What structure needs to be built for this feature?
1. Inlet and outlet
2. A syphon
3. Aqueduct
4. A level crossing

Answer 1

Correct Answer - Option 4 : A level crossing

Level Crossing:

(i) Canal and stream (drainage) meet each other at practically at the same level.

(ii) In this type of work, drainage water is passed into the canal and then taken out of the opposite bank.

Important point:

Inlet and outlet:

(i) Canal inlet is constructed when drainage flow is small and its water may be absorbed into the canal without causing the appreciable rise.

(ii) Outlet are constructed if the canal is small. Additional discharge entering into the canal is allowed to flow through outlet.

Aqueduct:

(i) Aqueduct is provided when High flood level of the drain is much below the bottom of the canal. So, the drainage water flows freely under gravity.

A syphon:

(i) A canal syphon is provided when Full supply level of the canal is much above the bed level of drainage trough. Canal run under syphonic action under the stream trough.