help with volume error

[ChristopherVol]

Our client dug a hole on a lot.  The lot had a building on it.  My gross area of the area is about 18,000 (doing 'properties' of the polyline around the hole).  It created a volume cut of about 99%.  But my area for the volume is saying about 17,000  (I think because it excluding the area where the building was from original because I built a boundary around it).  I need to do a volume for only part of the hole that was done for August.  When I draw that polyline the area is about gross 17,500.  When I apply that boundary to the volume for August it is giving me that entire area of 17,500 which is bigger than the whole area of 17,000!  And suddenly my volume is almost 50% cut / 50% fill from 99% cut!!! There should be 0 fill in this hole.  I had done a smaller area for July and that worked out fine.  I don't know why this is happening.  It's the same volume  I just changed the boundary around it from all to part.

[rkmcswain]

Can you provide some screenshots or even a hand sketch of what is going on?

This is what I'm picturing in my head.

[ChristopherVol]

They exactly what I am trying to do.  My original topo has a boundary (with a boundary around the building and a boundary around the wall).  My hole has a boundary.  

When I apply the hole surface boundary to the hole volume I get the full area and now a cut/fill of ~50/50.

gross area of the polyline: 18,779area for GIANT HOLE volume: 16,985 with a CUT of 1636no boundary on the volume (but the two surafaces have their boundaries)now applying the polyline to be the boundarynow my area and volume have changed!!: 18,764 with a cut of 1667 and a fill of 1585