Question

An existing rectangular storm drain on a slope of 0.008% carries peak flow at a depth of 7.5 ft.You are designing a new rectangular storm drain that will connect to the existing storm drain atthe same invert (i.e. channel bottom) elevation using a gradual, low angle transition section. If the new drain must convey a peak flow of 100 cfs and is to be constructed on the same slope,sketch plan view and specify an appropriate design base width and wall height of the new rectangular storm drain.

Fig: 1