General DEM elevation data processing tools for ArcGIS 8x are available from the following site http://moose.cee.usu.edu/taudem/taudem.html. I understand that the COE is working on an update to HEC-GeoHMS that will work within ArcGIS 8x.

I have been told that the Profile Extractor program available from the ESRI website is a useful tool for computing overland flow length and slope from DEMs or TINs.

Charles I. Moore, P.E.
MOORECI@CDM.COM