The Arc Hydro tools operate in the ArcGIS environment.
Some of the functions require the Spatial Analyst extension.
The majority of the tools are accessed through the Arc Hydro Tools toolbar,
where they are grouped by functionality into six menus and nine tools.
Additional tools have been developed in the geoprocessing environment and are available in the Arc Hydro Tools toolbox that can be used both in ArcMap and in ArcCatalog.