New to forum; hello to all. I looked through the forums and didn't see this one; might've missed it.

I have a small 2'x2' sinkhole on the edge of a 1/2 acre runoff pond. Pond can never fill beyond this hole, leaving it fairly low. The pond is half/three-quarter acre or so runoff that has a berm around it to capture the water (the hole is on the inside of a very low berm). Even with the hole it's never gone dry.

I'm getting ready to 'repair' it (per Uni of KY guide) with riprap, gravel, clay and dirt but am concerned that once the pond refills over it it will eventually leak through again.

Looking for any tips - liner in hole only? Then materials on top?

Since the hole is so small (rock fissure is about 1'x1', I thought maybe a 4x4 chunk of pond liner/sinkhole liner (or just 3ml plastic) before I start putting the materials in the hole.

Thanks for any help.