The peak runoff volume from the catchment between two contour bunds constructed on a 2.5% slope is 972.5 m³. The contour bunds have top width of 500 mm, height 600 mm, side slope 2:1, vertical interval 1.0 m and length 250 m. If the crest of the overflow weir is at a height of 300 mm from the ground and time available for the excess water to flow through the weir is 20 minutes, discharge in m³ per minute through the weir is
Options:
(A) 15.0
(B) 20.0
(C) 25.0
(D) 48.6
Official Answer Key:
D
Step-by-Step Solution & Explanation
The entire peak runoff volume of 972.5 m³ (the excess volume that must be safely passed through the overflow weir) is to be discharged within the given 20-minute duration. Discharge Q = Volume/time = 972.5 m³ / 20 min = 48.625 m³ per minute ≈ 48.6 m³/min, matching option (D). (The bund's geometric dimensions — top width, height, side slope, VI, length — fix the storage capacity that produced the 972.5 m³ peak-runoff figure but are not separately needed once that volume is given.)
Practice This in Real CBT Exam Interface
Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.