To download and install Arc Hydro tools for ArcGIS 10.7, you should use the official Esri distribution channels. These tools are free but require an existing ArcGIS software license. Official Download Sources
ArcHydroTools_10_7.msi or similar.Select the folder matching your specific ArcGIS version (e.g., download arc hydro tools for arcgis 10.7
Verify if you are running ArcGIS 10.7 or ArcGIS 10.7.1 , as they often use the same installer, but it is important to match the "build" number. To download and install Arc Hydro tools for ArcGIS 10