A trapezoidal concrete channel has a constant slope of 0.0015, a bed width of 3.0 m, and side slopes of 1:1. It carries a discharge of 20 m^3/s. The channel is a tributary to a river in which the existing flood level is 3.5 m above the channel bottom. Compute he water surface profile by the numerical integration method to a depth 5% greater than the uniform flow depth.