I have a 1 acre pond on my property that has a stubborn leak. The pond has not been maintained over the years resulting in numerous trees on the dam. I have removed many of them right or wrong. Currently it's around half full and leaks 1/4 inch per day. Last year this time it was 1/2 inch. With all the rain we had last summer, I think it helped plug the leak. My theory is this problem started when the pond was renovated about 6 yrs ago before I owned it. I know it held water fine 15 yrs ago.

Today I decided I'd dig test holes around the pond to see what clay content it had. This area of Kansas has really rocky and gravely soil. I didn't find any of that and great clay. That was until I reached the North end and found sand about 8 inches deep with underlying clay and some rock. Holes I dug filled with water that percolated through the sand. Could this be my leak? The area is about 20-30 ft across.

I still question my dam though it's not wet anywhere behind it. My original plan was to treat with soilfoc which I have a pallet of... 10 units I think. Should be plenty to treat my dam and maybe that sand zone but how well does it stop sand??

I have pics that I'll post when I figure out how