I am attempting to use the Storage Capacity tool in version 10.8.1, but the area and volume columns are only returning null values. It looks like this question was previously asked here, but not answered.
The vertical coordinate system of the dem is NAVD 1988 and the horizontal coordinate system is NAD 1983 UTM zone 17N. I'm not really sure what you mean by overlap? The units of z, and x,y are meters. Hopefully I answered these correctly, I am relatively new to the software.
By overlap he means are the polygons in the same coordinate system as the DEM. Just because they draw on top of one another doesn't mean they overlap, as the desktop software will project data on the fly so they appear to overlap when they really don't. If the tool doesn't handle this behind the scenes (this is an add-on tool [from the Spatial Analyst Supplemental Tools] not part of the main software) it won't work. (Note that add on developer tools, though useful, are generally less bulletproof than the shipped software.)
If the polygons are in a different CS (right click the polygon feature layer and look for Spatial Reference or Coordinate System) you probably need to project them using the Project tool to be the same as the DEM. The other thing that can happen is that your polygons need to be big enough to cover more than one DEM cell. For this particular tool also be very careful with the units and values of the parameters - double check to make sure they are reasonable values.
@NeerajRajasekar1 - Hi - let us know if you have additional suggestions!