I modeled a section by using Nays2Dflood and for a proposed expressway I increased the level of ground elevation on behalf of setting an obstrucle. I doubt some conditions of fallowed procedure and it is appreciated if someone could clarify fallowing things.

1. If we increase ground elevation by a polygon is it act as an obstrucle or is there any change of the behavior?
2. Can we increase the elevation of one section and introduce culverts by defining the invert level in the boundary condition? Does the culvert act in the same manner where we put an obstrucle on behalf of increasing the elevations?
3. How to introduce a bridge or a dam or a spill in IRic ?