Inspection of incremental discharges or conveyances across a floodplain cross section usually reveals the location of relatively heavier concentrations of flow. By determining these heavier concentrations of flow, the design engineer can usually find reasonable locations for each of the bridges. In some instances, the concentrations of flow and associated flow divides are quite obvious. In other cases, the distribution of flow may be subtler, and must be estimated analytically, which is most easily done with a hydraulic analysis program.