We tried loading a DEM based DTM into InRoads to compute contributing areas using the Display Source Areas tool. Unfortunately, the point based surface does not really lend itself to this tool. Too often, the triangulation algorithm forms faces that cut off what should be flow paths, due to the lack of breaklines.
Does anyone have a methodology that they found useful to identify contributing areas using other Bentley tools. If not with them, are there other third party tools that can filter out these types of obstacles?