ArcHydro Flow Path Tracing Tool

[OliviaChung]

I have used the workflow built into the toolbar to generate flow direction, accumulation, stream, stream link, catchment grid, drainage line and catchment polygons.  I saved all the files on the server for my college to continue on to define batch points and subcatchment delineations.  She added all the layers to a new blank map and was able to delineate watersheds with the point delineation tools. However, when she tries to use the flow path tracing tool, nothing shows. Same thing with the interactive flow path tracing tool. Anyone has encountered this problem before and how to fix it? Many thanks.

[MattNash]

Usually all you need for the flow path tracing tool is the flow direction grid (fdr).  Maybe the tool is somehow using the wrong grid.  Perhaps try loading just the fdr grid and then running the flow path tool?  

[MattNash]

Also, the flow path tracing tool creates a graphic, not a feature class.  Do you have the default annotation group for the data frame turned off?  If so, the flow paths are created but aren't visible.   

[OliviaChung]

Thanks for the response Matt.

Turned out it was the fdr layer that caused the problem. For some reasons, when I copy the fdr raster to the server using copy and paste, it changes the raster from 8-bit unsigned integer to 32-bit floating raster. Guess ArcHydro doesn’t operate when the raster is in the wrong pixel type. Weird that it doesn’t have any error messages or anyting just nothing happened when I clicked with the Flow Path Tracing tool. Anyway, for future reference, I needed to use the Copy Raster tool in the toolbox to copy the raster and then everything’s ok.

[MattNash]

Hi Olivia, glad you got it figured out. Thanks for the tip!

Matt