A 60-inch RCP outfall discharges into an earth channel with a bottom width of 5.0 feet and side slopes of 2 horizontal to 1 vertical. The pipe has a slope of 0.8 percent and n-value of 0.012 and...

A 60-inch RCP outfall discharges into an earth channel with a bottom width of 5.0 feet and side slopes of 2 horizontal to 1 vertical. The pipe has a slope of 0.8 percent and n-value of 0.012 and carries a design discharge of 85 cfs. Design a riprap apron for the outfall.