[Ski907]

Perhaps more involved, and not as quick as what you’re looking for, but we’ve had success using AutoCAD Civil3D to model site improvements using assemblies and feature lines, then those 3D surfaces are exported to a DEM and merged over the base terrain in RAS. A major benefit of this approach is that the hydraulic model uses the exact same geometry that is on our design drawings.

I’m curious to try AJ’s recommendations using GIS tools in ArcMap, which may be faster for quick preliminary work, or situations where design drawings aren’t being produced.

[Ski907]

We just had the same issue pop up last week. We were able to run our model in 4.1, but not in 5.0.3. RasMapper froze in 4.1 when we tried to do inundation boundaries, so it seems like it only ran in 4.1 because the XS Interpolation Surfaces are not calculated as part of the initial calculation as they are in 5.0.3.

We spent a while sorting our specific issue out, but we were able to get it to run and generate the XS Interpolation Surfaces by increasing the distance between our bank station points, i.e. moving them further away from the channel center. We took this to mean that there was some problem generating the TIN used for the XS Interpolation Surfaces when the bank stations are too “tight” around the channel.

Hope this helps!

[Author]

Posts