This is my new post so please bear with me. I am having trouble generating inundation map on ras mapper. I did the analysis and have water profiles but somehow inundation map is not generating any help is appreciated. I can send the files I have been working on as well.
I ran your model and it worked fine. You need to associate the terrain with the geometry and plan. In RAS mapper, right click on the Terrains heading and select “Geometry associations”. then select the terrain to be associated with the plan (it may do this automatically for you as you only have one plan and terrain). Then run the model and the inundation will then be shown. As you have only done a 1D model with cross sections the terrain is not being used. to use the terrain where the channel spills over you need to create a 2D flow area and then connect the 1D cross sections to the 2D area so that water can spill between the 1D and 2D areas.