Floodplain Delineation Using Grids

[ShikoNjuno]

Hi folks,
I'm hoping someone can help me resolve this issue.
I'm trying to run the for-mentioned tool in ArcGIS but I keep getting this error.
[ATTACH=CONFIG]29257[/ATTACH]
I have no idea where to start troubleshooting so I was wondering if any of you have ever experienced this before.
Any suggestions welcome.
Thanks

Shiko

[MattMead]

Georas does weird things when you try working with grids. The georas mapper is such a black box we dont even try to use it anymore.  Based on the line in the error saying its possibly an empty feature class as an output I would first verify that all of your files are in the same spatial reference. 

Do you have a 3dAnalyst license?  If so, I would convert your terrain and water surface grids to TINs.  Then you can use 3dAnalyst-> Triangulated Surface->Surface Difference.

This outputs a polygon shapefile of your floodplain and has the option to output a depth grid as well.  Hope that helps.