The readme.txt inside the ArcGIS Pro folder (http://downloads.esri.com/archydro/archydro/setup/Pro/readme.txt ) must say: 1. Extract the zip file to the location where you want to install ArcHydroPro 2. Edit the file archydropython.pth so that the path points to the location of ArcHydro\Scripts\ArcHydro (e.g. C:\Tools\ArcHydroPro\Scripts\ArcHydro). 3. Copy the edited archydropython.pth to %ProgramFiles%\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\lib\site-packages. Otherwise you won't be able to run ArcHydro from ArcGIS Pro. ArcHydro uses Python from the default conda environment arcgispro-py3.
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