Error in "Level DEM": Spatial reference does not have z unit and in "Sink evaluation"

Question

I wanted to get the drainage area, but when I was doing the first step, "Level DEM", I got this error "Level DEM: Spatial reference does not have z unit" 
Does anyone have the same problem with this? Is there a solution to it? Is there a way to add z unit to the raster?

I just ignored this error, and moved on with the following steps. Everything was fine until I got to "Sink Evaluation". It says:
"Spatial reference does not have z unit.
Z factor computation did not succeed. Do you want to use a factor of 1 and proceed?"

I clicked yes.

So it started to calculating, and after a while, an error window popped out, like this: 
"System. Runtime.InteropServices.COMException(0x80004005):Error HRESULT E_FAIL has been returned from a call to a COM component. 
at ESRI.ArcGIS. Geoprocessing. GeoProcessorClass.Execute(String Name, IVariantArray ipValues, ITrackCancel pTrackCancel)
at ESRI.APWR.ApHydro.ArcHydroOp.SinkEvaluation(ApLayers apLayer, Double
zuNITfactor,Int32 debug,ITtrackCancel&trackcancel, IGPMessages&messages,String&exMessage)in
C:\Projects\10_Final\ArcHydroTools\src\ApHydro\ArcHydroOp.vb:line5747"

does anyone know what was wrong? is there any solution? Thank you a lot!!

RajatChopra · Answer

I wanted to get the drainage area, but when I was doing the first step, "Level DEM", I got this error "Level DEM: Spatial reference does not have z unit" 
Does anyone have the same problem with this? Is there a solution to it? Is there a way to add z unit to the raster?

I just ignored this error, and moved on with the following steps. Everything was fine until I got to "Sink Evaluation". It says:
"Spatial reference does not have z unit.
Z factor computation did not succeed. Do you want to use a factor of 1 and proceed?"

I clicked yes.

So it started to calculating, and after a while, an error window popped out, like this: 
"System. Runtime.InteropServices.COMException(0x80004005):Error HRESULT E_FAIL has been returned from a call to a COM component. 
at ESRI.ArcGIS. Geoprocessing. GeoProcessorClass.Execute(String Name, IVariantArray ipValues, ITrackCancel pTrackCancel)
at ESRI.APWR.ApHydro.ArcHydroOp.SinkEvaluation(ApLayers apLayer, Double
zuNITfactor,Int32 debug,ITtrackCancel&trackcancel, IGPMessages&messages,String&exMessage)in
C:\Projects\10_Final\ArcHydroTools\src\ApHydro\ArcHydroOp.vb:line5747"

does anyone know what was wrong? is there any solution? Thank you a lot!!

U can solve this Error By changing the Coordinate system of your DEM. Generally DEM files are in Geogrpahic refernce System but change it to projected co-ordinate System and later change the Z- value also in adf.prj  set this to 1 or if the llinear unit is set to centimeters set Z-value to 1

BarbaraGreenhill1 · Answer

Hi, do you have the latest version of ArcHydro? I had the same problems and was told by esri, that there was a bug related to the level DEM function. So check out the ftp server to see if you have the latest version!

LornaMurison · Answer

When I get a message saying that the spatial reference does not have a z factor it asks me if i want to use the horizontal scale (or something) instead, and then proceeds anyway.
Depending on what type of raster you are using... if you are using an esri GRID then you can add z units by using windows explorer to find the GRID folder and opening the prj.adf file within that folder.  Change Z-Unit (or z-something) from No to a number.  The number represents the number z units present in one spatial reference unit.  So if you're using UTM and your DEM's values are in metres then you would say 1, if the DEM's values are in cm you would say 100.