A trapezoidal channel with bottom width b = 30ft, side slopes m = 2, and flow Q = 5100cfs given, and I am supposed to plot a specific energy curve (E vs y). That part I have done. For the second part, it is given that 3 bridge piers, each 2 ft wide, are spanning the channel. With the same m and b = 30-3(2) = 24 ft, I need to calculate another specific energy curve. Question: Is it really that easy? Just change the corresponding x-s area A because of the new b, or does the flow change as well? Thanks in advance!