When an economical canal cross-section is formed partly in cutting and partly in filling, such that the quantity of earth in cutting is equal to the quantity of earth in filling, the depth of cutting under that situation is known as __________ .

Correct option is A

Balancing Depth :- Balancing Depth comes when the canal is in partially embankment and partially in cutting.
• It is the depth of the canal (H) that gives an equal amount of filling (i.e. Earth required for the formation of banks) and cutting (earth from digging).
• For a given cross-section of the canal, It has only one balancing depth.
• For this depth, the canal will be economical.
• For Balancing depth, Area in cutting = Area in embankment.
Critical depth:- Critical depth occurs when the flow in a channel has a minimum specific energy. Specific energy refers to the sum of the depth of flow and the velocity head. Critical depth depends on the channel shape and flow rate.