If your water table is that close to the surface and it is always that close to the surface you could have a water table pond and it would not mater that it is sand. You might not be able to have very steep banks however.
If the water table moves down in the dry times then so will your pond as you probably know.
Yessr, water table is generally pretty high but of course fluctuates with the rain. I need to do some more research on Bentonite, I wonder if it will still seal the pond if there is standing water already in the pond?
