Have 2 acre pond and is leaking under dam [about 1/2 to 1 inch in 24 hrs , any idea what will stop the leak?

Answer 1

Please don't add dry concrete mix to your pond. A concrete pond is supposed to be "cured" even after it is dry before fish and plants are added. I'm pretty sure dumping concrete into your pond will radically change the water chemistry, killing any fish or other pond inhabitants.

In my area we have calcareous clay which allows water to seep through, but even with heavy clays an earthen dam will seep and can develop dangerous leaks. Animals from muskrats to beavers can seriously damage an earthen dam. Sometimes tree roots are the problem. Whatever the cause the normal course is to apply a bentonite clay layer. Normally you need to drain the pond, but the website below lists a granular Sodium Bentonite that can be sprinkled over the area. It is listed as environmentally safe.

Answer 2

I have also heard of using gypsum, not sure if it work on the size leak you are refering to. I have even seen people use sheets of sheetrock.
www.pondboss.com is a good forum for finding answers on small ponds

Answer 3

get yourself a new beaver, just joking, you might have to empty the pond to repair the leak, you did not say how the dam was built

Answer 4

Unless it completely drains it, I say, let it drain down to where the "leak" is, then you'll be able to plot a course of action.
It could be something minor, or something major, you won't know until you see the leaking area from the inside, unless you have SCUBA equipment.
Good Luck

Answer 5

Dump a couple of bags of dry concrete down in it, slowly. It should slowly work it way into the hole, and plug it up. Sounds like a turtle is making a home in there.