I posted a while back about my situation, to were I have about 1/2" of water loss, which is up slighly from were it was after it was done 1/4", in my .62 acre pond. The pond was biult last March of 04. And the only water I can find is probably 20ft or so behind the dam and about 10ft from a creek that is flowing parallel to the dam.

There are 2 spots that have trickling water and both have the iron bacteria growing in it. I've noticed that when we have a dry spell one of the leaks gets less and less, and the other stays about the same.

It doesn't really seam like if both of those are indeed coming from under the dam they are not leaking enough to cause that much water loss.

When we were digging the pond they hit rock in the middle, which they did not pack clay over. The pond started filling up with ground water so quickly that it made it difficult to work the bottom that much.

With all that said, I'm really wanting opinions on
If you all think that 1/2 is acceptable and if you all think that it may begin to seal some as time goes by?

Here are some pics of the construction.

I'd worry about the ground water that started appearing when you were excavating. If it is a spring or a seam from the creek, it will run both ways. Depending, of course on which is the lowest.

Also, when they hit rock, they may have hit a rock strata that goes to the rear of the dam and shows up at that point.

I see nothing to seal it but I would personally be very happy with only a 1/2 inch loss per day. Heck, I have that much evaporation.

Maybe I'm being a little silly about it (as my wife will tell me) but it really bothers me that it doesn't stay full to the top all the time.

scsims :
You should look into bentonite clay. It can be purchased in dry powder form from oil & gas drilling companies in 50lb. bags. You mix it with water and the goo like clay sinks to the bottom and toward the leak. When it gets there it fills the leak just like you had packed clay to start with. There are other posts on this site and an article in a recent PONDBOSS on bentonite. Good luck--ewest.

I've been told by professionals that the bentonite never works. I'd be very cautious with that approach, especially with water already in the pond.

Trying to get bentonite to drop on top of a "possible" leak and plug it would be like dropping a bare hook into the water and expecting to hit a fish on the head with it. Chances are slim.

I respectfully disagree. The "sprinkle method" does work sometimes as it has worked for me to stop seepage in a small holding pond. However I would not mix it with water before applying. I would dump a bag or two at a time in a wheelburrow and shovel it in the waters edge of the dam. Or very carefully dump in with a frontloader. The bentonite will quickly get saturated with water and sink to the bottom. You should be able see where it settles once the water clears. Spread it about an inch thick if you try this.

No guarantees but it worked for me.

I second Cecils comments, I had a area on back side of my dam that stayed wet (approx. 4'wide by 10'long, no depth just wet) last summer when we had no rain for a couple months and everything real dry. Talked to my contractor several times and always got the (I'll stop by and take a look)it is now 9 months later and still no word from him. So after 3 months and several calls to him and no response, I bought the benonite from my well drilling supplier $11 a 50lb bag. I bought 5 bags 3 different times and used a feed scoop to just broad cast it in the area on water side of dam straight across the dam from where my damp spot was located. Made my bentonite about 2 to 3 inches thick and area stays real white for long time so you can see easily where benonite lands It is now 9 months later and my neighbor and I both think the problem is fixed because he would always mow up to my dam and he always would leave muddy trail where he would mow in this area, seems to have worked for me too. All seepages are different so like Cecil says no guaranties, but for couple hundred bucks it was worth the try to me. Hope this helps. PO