A river channel and flood plain slope at 0.0009 and can be modeled in 3 segments. The river channel itself is 20m wide and flow depth is 5m and the sandy bottom has an n=0.02, the left bank is 40m wide and the flow depth is 0.5m, while the right bank is 100m wide with a flow depth of 1m. The n value for the two banks may be assumed to be 0.04. Estimate the flow rate in the cross section