Question

Which one of the following is not a function of under sluices in a weir
1. to control silt entry into the canal
2. to pass the normal discharge without operating the shutter gates of the weir
3. to regulate the supply of water entering into the canal
4. to scour the silt deposited in the river bed above the approach channel

Answer 1

Correct Answer - Option 3 : to regulate the supply of water entering into the canal

Explanation:

Under-Sluices (or Scouring Sluices): The under sluices are the openings that are located on the same side as the off-taking canal and are fully controlled by gates, provided in the weir wall with their crest at a low level. Their main functions are:

(i) It helps in controlling the silt entry into the canal.

(ii) It scours the silt deposited on the river bed above the approach channel.

(iii) It passes the low floods without dropping the shutter of the main weir.

(iv) It preserves a clear and defined river channel approaching the regulator.