That's a bummer. Don't give up. Have you thought about the following possibility?

Breach the dam and dry it out for a summer.

Then get a dozer for a half a day and resculpt the area to accomodate a quarter acre pond that's just the right size for a liner.

We'll help you out anyway that we can no matter what you choose. Any one of us will help you as much as possible to get the best deal on a liner, then stock it for your dream fish. My .15 acre pond is the best fishing pond on my property. LOTS of big fish for it's size.

We'll help you any way possible!!

Holding a redear sunfish is like running with scissors.