78703TX,

With your situation it may be hard to find someone willing to take on the risk of a guarantee. Here are a couple of thoughts.

This pond pretty deep for a 1 acre pond and you mentioned it was bone dry. The only way this can happen is if the bottom is exposed to water conducting strata. Caliche has varying amounts of clay and lime. Where the lime prevails it is very brittle and water dissolves pathways through it. In north Texas, the springs are often sourced to fractures in the caliche. There might be exposed fractures providing the pathways.

You didn't mention if their is a ravine providing the depth or if it was actually dug 20 feet deep. I think if it were me, I would consider using the topsoil from the land. You need to be sure that no rock strata has exposure to the water. It would probably still percolate some but this should abate over time as organic matter accumulates. In time I think you'd have a pond that holds water well enough to meet your purposes and expectations.

You should still find help as you are doing. Slope of the bottom and its thickness would be important to the stability of your repair.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers