A 10-feet trapezoidal channel is designed to carry a discharge of 1,000cfs with side slopes: Z1 = 4 and Z2 = 5. The channel bed slope is 0.04 ff/ft and has Manning's N of 0.03. To protect the channel from erosion, the normal flow velocity for the design discharge has to be reduced to 7.0 fps or below, and the flow Froude number must be reduced to 0.80 or below. To satisfy the above criteria, a drop structure is to be installed as a grade control for a reach of 200 feet.