HEC-GIS (aka HEC-GeoRAS)

Import geometric data from an existing digital terrain model (DTM) within ArcInfo, in the form of triangulated irregular networks (TINs).
Create coverages within ArcInfo to represent the attributes associated with a river, such as cross-section geometry, bank stations, and so forth.
Import HEC-RAS water surface profiles back into HEC-GIS to perform additional spatial analyses and mappings.