Install Arc Hydro first, followed by HEC-GeoRAS.
HEC has largely transitioned away from GeoRAS because (including 6.0+) now includes RAS Mapper . hec georas for arcgis 108 upd
Both 3D Analyst and Spatial Analyst extensions must be installed and active. Operating System: It is strictly compatible with Windows . Install Arc Hydro first, followed by HEC-GeoRAS
If you have older versions of GeoRAS, GeoHMS, or Arc Hydro installed, remove them first. Install Arc Hydro first