Downloading and installing requires patience and attention to version compatibility. By using the official Esri GitHub repository, verifying pre-requisites (Spatial Analyst, Python 2.7, .NET), and following the step-by-step installation guide above, you can successfully equip your ArcMap 10.7 with one of the most powerful hydrologic modeling toolkits available.
Arc Hydro Tools are built as an Add-in (or previously as a DLL extension) that integrates deeply into the ArcMap interface. Because Esri updates the underlying .NET framework and ArcObjects libraries with every release, an Arc Hydro build designed for ArcGIS 10.5 may crash 10.7, and conversely, tools built for ArcGIS Pro will not work in ArcMap. download arc hydro tools for arcgis 10.7