Pond Boss Forums GENERAL QUESTIONS Help Pond Leak?

Last year we bought an acreage with a pond that had a leak at the dam. $7,500 and a year later our 1/2 acre pond is almost full. Here's the problem, 5 days ago, we noticed that the back of the dam was wet with some standing water. Today I noticed that the pond is down about 1/2" - 1".
Originally the dam was built without a clay core, thus there was a serious leak. We hired a contractor who dug out the center of the dam and filled it back in with a mixture of the existing soils and bentonite.
My questions are: If there is noticable leak now, will it get worse? Is there a chance that the bentonite will eventually swell enough to fix the leak?
The contractor did tell us that we will notice the pond going up and down at first.

welcome to PB grovers.

you say the leak is on the back of the dam. is it at the base, midway up, or near the top, in other words, where is the leak in relation to the water level on the other side?

when you describe that the contractor dug out the center, i presume you mean he dug a trench along the length of the dam, and not across the dam. did he dig (and re-fill) below the original bottom of the dam?

its a tough question you pose, but answers to the above questions may help to figure out yer problem.

And did he compact the center trench when he refilled it?

And just how did he compact it?

And what was he wearing when he compacted it?

Dont tease Theo and Dave. They are always dead serious.
BTW Hillbilly. Can you give us specs on the Engersoll Rand compactor? Is it pulled or walk behind? Details. Sounds like a good idea.

:D
Thanks, TNHB - I was trying to find an indelicate way to ask that.

The water is at the bottom backside of the dam. Initially we just thought it was runoff from the dam and the surrounding hills. But now that the water level of the pond is slowly going down, and the water at the back of the dam is not drying up, we fear that there may be a leak.
The contractor dug a trench that was the entire length of the dam. The trench was dug below the bottom of the dam. It was at this level that he hit all black dirt... no clay.
When he refilled the trench, I don't believe he compacted it. Unless driven his machinery over it a few times is considering compacting it.

grovers, please pardon my, uh, friends, uhm, and yes i am always dead serious especially about a leaky pond, they arent fun.

boy it really sounds like underflow. i'm not sure if compaction is as critical with bentonite, but sounds like he should have used a sheepsfoot roller or something other than just his equip, to compact. also, if he didnt get the trench deep enough, the bentonite wont help, but like he said it might take some time to swell and plug leak.

monitor the rate of the leak. obviously, if it decreases..great....if it increases and persists more than a few months, you still have a problem.

i fixed my underflow problem by putting a large clay patch extending from the lower part of dam (on the pond side) across the deepest parts of the pond basin. obvisouly this was done with no water in pond. IIRC, others here have had some luck patching the back (dry) side of dam.

good luck and post updates.

The compactor I used was like this, except an older model, with a padfoot roller.

http://road.ingersollrand.com/Model.html...D-1A7AF54B8 9D0

Oh, you meant a COMPACTOR. Thanks. $500 a day, huh?

I spent about $500 total for the rental, delivery (30 miles), and 40 gal diesel. I had it delivered on Saturday morning and they picked it back up Monday, I put about 10 hrs on it over that time. It definitely did the trick for my soil. Our weather is pretty dry right now for this time of year and the pond is holding great at this point. I've got pics of the compactor I used, It was an SD 100. I'll post them when I get a chance.

Had a guy once tell me that the pieces of sheetrock floating in his pond was to help seal the leaking dam. Is there any truth to that?