Currently, in Revit Site Designer, it is unclear what topography is being used for Site Designer's dynamic toposurface. The toposurface using Site Designer should be listed in the properties.
The reason this is necessary, is if you have many toposurfaces, it can be hard to find which of the toposurfaces is dynamic and you can only have one Site Designer toposurface active at a time. If you try to create a new toposurface on any surface other than the Site Designer Toposurface it will delete the dynamic Site Designer Toposurface.
Having which surface is currently using the Site Designer would, at least, make finding the dynamic surface easier. This is ignoring the workaround needed to change to a new Site Designer Toposurface (idea to improve this will be separate).
