I need to do some volume calculations of bunds. I suppose I should use the Surface Volume tool in 3D Analyst of ArcGIS. Here is the tool description. I am uncertain about the plane height parameter, however. From the tool webpage there is a diagram showing a plane height that intersects the surface. This seems to match our circumstance, where the bund rises above the polygon describing the external edge of the feature, but then dips below the plane of this polygon on the internal face of the bund going down to the base of the pit.
Here is the complicated part. The elevation of the external edge of the feature differs. Since, therefore, it is not a perfectly horizontal plane, it doesn’t seem sensible to me to put in an elevation value for the plane height. If a constant value were used, then the bund may not be cut at its external base where the elevation on the boundary varied above or below that value.
I see there is also the cut/fill tool. To me this would require a raster of the polygon describing the outer, bottom edge of the bund to be supplied. I'm not sure how to produce a valid raster representing this plane, however.