Watersheds, using DEM and stormwater network

Question

Hi all
I would like to generate watersheds for an area using the tools in spatial analyst. The area is situated in a city where there is a stormwater network that will influence on the catchment areas. 
Would it be correct to use the raster calculator to combine the DEM with the storm water pipes? Or should you solved this in another way?

AndrewMoffitt · Answer

Hi all
I would like to generate watersheds for an area using the tools in spatial analyst. The area is situated in a city where there is a stormwater network that will influence on the catchment areas. 
Would it be correct to use the raster calculator to combine the DEM with the storm water pipes? Or should you solved this in another way?

In my experience doing this, I have used the storm drainage network as cutlines to my DEM.  I use GeoHMS (free) to do this.

LindaJohansson · Answer

Thank you a lot for your answere!

MarkEllis · Answer

I supported such a project some years ago and recall doing exactly that.  Because the drainage follows your stormwater network, the DEM should be forced to comply with the network.