A grouted-riprap, trapezoidal channel (n=0.025) with a bottom width of 4m and side slopes of Z=1 carries a discharge 12.5m^3/s on a slope. Compute the backwater curve (upstream water surface profile)...

A grouted-riprap, trapezoidal channel (n=0.025) with a bottom width of 4m and side slopes of Z=1 carries a discharge 12.5m^3/s on a slope. Compute the backwater curve (upstream water surface profile) created a low dam that back water up to a depth of 2m immediately behind the dam. Specifically, water depths are required at critical diversion points that are located at distances of 188m, 423 m, 748 m, upstream of the dam. ( Hint use standard step method).