Getting Started with HEC-GeoRAS for ArcGIS 10.8 HEC-GeoRAS remains a staple for hydraulic engineers who still rely on the ArcMap ecosystem for flood modeling. While Esri has retired ArcGIS Desktop as of March 2026, many specialized workflows—like those requiring the HEC-GeoRAS toolbar—are still active in 10.8 environments. What is HEC-GeoRAS?

Future-Proofing: Since Esri is retiring ArcMap in March 2026, you should consider migrating to ArcGIS Pro and leveraging HEC-RAS's internal RAS Mapper tools, which handle most of GeoRAS's original functions without requiring an external GIS extension.

Downloading and Installing HEC-GeoRAS:

• You need 64-bit native processing for huge rasters.
• Your organization is sunsetting ArcMap licenses.
• You require integration with ArcGIS Online or Portal.

• 1-meter or 3-meter LiDAR-derived DEM for detailed studies.
• 10-meter NED (National Elevation Dataset) for regional assessments.
• Ensure the DEM is in a projected coordinate system (e.g., UTM, State Plane) – never use geographic (lat/long) coordinates.

Get Started with HEC GeoRAS