Burning Culverts into a DEM

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09-27-2021 07:19 AM
KatieBalaze1
New Contributor

I am working with a large DEM to create a watershed map for an entire municipality. I am trying to generate streams using the DEM rather than burning in national hydrography dataset streams as they don't line up well. I have identified areas where bridges/roads are creating walls and created a culvert line feature class with lines across these roads. I used this feature class in the create drainage line structures tools, but when I move on to DEM reconditioning I get the following error "['line 235', 'c:\\program files\\arcgis\\pro\\Resources\\ArcToolbox\\Scripts\\ArcHydro\\demreconditioning.py', "TypeError: '<=' not supported between instances of 'NoneType' and 'int'"]". Should I have checked the "use raster extent" box on create drainage line structures? Or is there another reason I am getting null values?

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I burned culverts recently and ran into this.  One way around this is to create a polygon that is the size of your DEM extent with a value of zero.  Then merge your culvert buffer polygons with nonzero cut depth with that zero polygon and make the cut raster, so that your cut values are zero or desired cut values and not null values.  If there is an easier way to calculate null values in the raster to zero I have not found it.

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KatieBalaze1
New Contributor

It seems that I had to change the processing extent to the overall DEM extent within the analysis tab-> environments and that worked.