Water surface data exported from HEC-RAS can be imported into InRoads.  InRoads can import two different HEC-RAS output file types:  *.gis and *.sdf.

Workflow

1. Enable the Hydrology and Hydraulics Add-In by going to Tools > Application Add-ins and toggling on the option for Hydrology and Hydraulics Add-In.  Click OK.
   
   
   
   
2. Select Evaluation > Hydrology and Hydraulics > Generate Water Surface Data.  Set up the dialog as shown in the dialog below.  Ensure that the "Create" field is set to Water Surface and the "Section Format" field is set to HEC-RAS.
   
   
   
   
3. Select Apply and select the *.sdf or *.gis file that you wish to import.  Select Open.
   
   
   
   
4. After the import processes, the newly created DTM will have been created based on the HEC-RAS output data.