PE Civil Practice: Determining Flow Rate in a Rectangular Open Channel using Manning’s Equation

NCEES Civil PE Specification Hydraulics and Hydrology: Stormwater collection and drainage (open-channel flow)

Problem

In a rectangular open channel water flows at a depth of 5 feet, as shown in the figure. Assuming a constant Manning’s roughness coefficient of 0.015 and a longitudinal slope of the channel bed at 0.6%, the flow rate (in cubic feet per second) is most nearly:

Select an Answer:

A) 600 cu ft/sec
B) 900 cu ft/sec
C) 1,200 cu ft/sec
D) 1,500 cu ft/sec

Practice Question: Determining Flow Rate in a Rectangular Open Channel using Manning’s Equation

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