Compute the water surface profile upstream of a road crossing over a trapezoidal concrete-...

Compute the water surface profile upstream of a road crossing over a trapezoidal concrete-lined (= 0.015) channel. The channel has a bottom width of 3 0 m (9.8 ft) and side lopes of 2H:1V. The slope of the channel is 0.0005 and the discharge rate is 20.0 cms (706 cfs). The starting water depth (y1,) upstream of the road crossing is 4.0 m (13.1 ft).