My student seems to have done all of these things and while we are able to model the depth below ground, when you look at the model in transect, the depths are all off by the approximately our elevation. For instance, the first pond is about 2.9 meters deep, but it shows as 950 meters deep and our elevation is about 947 meters. I am sure this is something so obvious, but I am not thinking of it.
Also I am sorry I do not have a screen shot. I do not have that part of the project handy, but can get it, if you need it.