Pond Boss Forums INTRO Questions & Observations New pond level drop - should I be concerned?

UPDATE: After the spring record rains flooded this entire ravine and got this pond within a couple feet of being full, we have been losing 2" per day and have lost over 3.5 feet over the past month or so. This is the case even with a small amount of spring activity putting a bit of water in each day from upstream. It is not leaking behind the dam - no wet spots anywhere. This is a damned up ravine and while I think the belief that absorption was the initial culprit costing us 1/2 inch per day when it was lower - with a consistent 2" per day drop we definitely have a bigger leak problem than that. Needless to say, after my elation with the pond filling it has quickly turned to disappointment.
With no leak on the back of the dam I assume that the leak is coming from the bottom of the basin where he did the betonite slurry fix and we are losing the water going under the dam or someplace upstream we are piping water under the clay and then under the dam. With no visible leaks on the back of the dam, the contractor says at this point there is little to do but wait and see if the pond stops leaking at a certain level and determine if there is a problem at that elevation where the leak slowed. Of course if pressure if forcing the water through the bottom, a lower pond level could slow that only to return when the water level comes up again. Any suggestions on how to determine where the problem lies?