Pond Boss Forums POND CONSTRUCTION Building a dam Success with bentonite?

Hello,

I am interested in hearing from anyone who has had success in stopping or slowing a leaky pond dam with bentonite applied through the water column. What is your experience?

Take care,
Patrick

I had a sizeable leak in my dam that originated near the surface on the pond side and exited at the bottom on the back side of the dam. I lowered the water level until the leak, which I could hear slurping, was at the surface and slowly poured bentonite powder from a coffee can into the hole. After about 3 cans worth the flow slowed noticeably and I didn't add any more. I drove a stake into the ground to mark the spot in case I had to go back and re-treat it but that wasn't necessary. The leak is gone, the bottom of the dam dried out and it hasn't re-appeared in 2 years. I keep a 5 gallon pail of the stuff in my garage because it seems to work very well.

Hello PaPond,

It is great to hear from someone who has actually had success just dumping bentonite in a pond! It sounds like locating the exact point of the leak helps.

Take care,
Patrick

We put out 12,000 lbs of pelletized bentonite about a week and a half ago. We are currently pumping water into the lake out of a well so it is hard to indicate whether the lake is holding water better or not but I will say that the well didn't run over the weekend and it maintained it's water level. We found a few areas that had some "bubbling" in the the water and we put several bags around those areas. The other areas we tried as best we could to evenly distribute it. We did put out just over 1.5x's the recommended rate also......just wanted to try to ensure that if possible we would make a good solid bottom. We made the mistake of getting some of it on the back of the boat near the water line and man that stuff is tought to get off the back of the boat.....I can only imagine how it has adhered to the bottom.

Hello Lee,

Keep me posted on the status of your repair. I have a small pond (1/2 acre) but I'm getting some seepage from the backside of the dam. It seems to be localized in a 10'-12' area, however I don't know at this point where the leak originates inside the dam. It could be directly across from the seepage or it could be traveling through the dam and just showing itself there. What was the application rate for your pond?

Thanks,
Patrick

Patrick,

We put out about 1-1.5 lbs per sq/ft. Basically we had closed off an old ditch with a 400' damn and it was suppose to produce about a 7.5 acre lake. It's filled several times but it drops rather quickly. We've looked many times for leaks and have never found any wet spots. I'm 99.999999% sure that the leak was in that ditch bottom because there was some sandy that was in the bottom. We were told by our fsa office that it would probably silt in over time. Well it's been almost 2.5 years and it has dropped consistently. So this year we put out the bentonite and put in a 4" well that is running off of a generator with a 100 gallon fuel tank as we speak. I should be able to get about 100,000 gallons/day added to the lake. So if that is right then hopefully by the end of the week it'll be up at least a foot or so because right now the lake is only covering 1 to 1.5 acres but once it starts to rise it will widen and the rate of rising will diminish as it fills up. Right now I'm hoping that Ivan will bring some rain our way.....man 8-12" of rain would do me wonders.

-lee-

Lee,

Thanks for the info. Good luck with the rain...I hope the wind stays clear of your area though.

Best wishes,
Patrick