Do you have muskrats?Theyll put hole in it quick.

The only thing pigs did for my father's pond was root out the dam and erosion caused the pond to drain over the next few years.

If this pond was built over a "sink hole" then it sounds like the sink hole has opened up and developed a leak. Not knowing where your pond is situated, it would be hard to say what your best approach would be. If this pond is at the head of a hollow you might do down below the dam and look for wet spots or actual streams of running water that you've not noticed in the past. The water may follow a ledge of rock and some out where you least expect it.

Fixing a pond leak is not cheap and is not a guarantee. Just because they drain and core the pond doesn't mean that it won't continue to leak, especially if it has a sink hole.

Good luck.
Janet

You referred to the pond as a "sink-hole pond", does this mean there is no dam structure? If there is a dam, I would definately look closly for signs of muskrat dens. If there is no dam, it is possible the sink hole is still sinking and may have developed a leak . Pigs will only help if the leak is along the edge in shallow areas. I have heard of using straw or hay to help seal a pond, don't know how good it works.

Clarification: pond is on a flat piece of land; no dam, no muskrats; surrounded by shelves of limestone. Limestone is the type used for making those famous KY stone fences. Lot of fossil brachiopods in evidence.

Spoke with a natural resources, "pond doctor," rep today for advice. He said that since the pond level has been unchanged for about a year, it is likely the leak is at the current water level. Sink hole ponds are very common in this area of KY.

He said pigs might effect a seal if we dumped several loads of clay around the perimeter and the pigs had a chance to wallow the area. The pigs' tiny hooves would compact the soil equal to or better than a monster machine.
Cost would be much less than machining. He said in this area, there is no guarantee whether compaction is by machine or swine. He did not mention straw, but that seems like it's worth a try.

This pond is famous for its' minnows, used by fishermen whose own farm ponds do not host these 'shiners.'

"Pond doctor" said that if the leak were at the bottom, we would see almost no water.

Currently, will see if we can get a few scoops of pasture clay spread around perimeter and then get some electric fence for a couple of pigs. Of course, this means building a shelter for the porkers and....Rube Goldberg project escalation!

Thanks for the comments. To be continued.
cella jane

Blueberrier, my father, from SE MO, told me about the hog solution but he said it was better for new ponds. (Ones that were excavated and had a dam and spill way.) He said that the old timers would feed a herd of hogs in the bottom of new pond for several months and that their hooves and wallowing would compact the clay and make the pond water tight. As to your pond I doubt this "cure" will work. I think the leak is the water following a shelf of rock that has resulted from either the shifting of soil along the shelf or it being washed out. All I can say is that you can try and at the worst your pond level will be low and you've got bacon and ham on the hoof!