Download the matching ArcHydro version for ArcGIS 10.8 from the Esri or HEC repository to ensure seamless tool execution. Installation and Setup Guide
While the USACE Hydrologic Engineering Center shifted its development efforts to integrate GIS tools directly into the standalone HEC-HMS application, legacy GIS environments utilizing still require the dedicated HEC-GeoHMS extension to streamline older watershed delineation workflows. Technical Compatibility Matrix download hec geohms for arcgis 108 exclusive
This guide provides everything you need to download, install, and troubleshoot HEC-GeoHMS for ArcGIS 10.8. What is HEC-GeoHMS? Download the matching ArcHydro version for ArcGIS 10