I'm trying to model a river in Hec-Ras. I use Arc-Gis and Arc-georas to export data to Hec-Ras. I have an issue with digitizing the flowpath. I don't know it should be parallel to main channel or floodplain boundary? Or it doesn't matter?
I think that technically the flow path (if you use it to measure the distance between cross sections) is to represent the "center of the mass of the flow" (see Reach Lengths on page 3-12 of the HEC-RAS Hydraulic Reference Manual: you can find it via the Help menu in HEC-RAS).
