Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? Fixing a leaking hole in pond bottom

I’m finally getting back into my pond project after spending the last 3 weeks getting it drained with a 2” semi trash pump. I could have waited a few weeks and it would have leaked out by itself but I’m anxious to get it sealed before the spring rains. I’ve heard from different neighbors the pond used to hold water with 5+ lb bass some years ago. I’m not sure why it started leaking but after using a 4 ft probe all around in 4-6 inches of muck I found a 5ft diameter muck hole where the probe will sink almost to the handle before hitting solid ground. I suppose I will rent a backhoe to get all the muck out and fill with a clay mix ,and compact . Could it be the top of a water table or something? When the pond is full from the rains it will lose 4 to 6 inches a week it seems ,and my neighbors yard down the hill and across the road is a swamp until my pond leaks down a few feet. I have 2000 lbs of bentonite on hand and plan on putting about 5 pounds per square foot in the area around this hole . Does anyone have any ideas or suggestions? I plan on mixing or blanketing bentonite on the entire pond bottom eventually but hoping this is the only spot it’s leaking and solves the problem.

Thanks,
Marty

Marty, I would concentrate your work in those soft areas first, then move out to the rest of the pond. I agree about getting an excavator and digging out those areas to work on.

Thank you for the advice. I will do that. The rest of the pond bottom feels pretty solid when probing around but I will probably try pushing some of it to this deeper end with the hole to save money on bringing clay in by truck. I plan on renting a ride on sheep’s foot roller to compact the entire pond bottom and sides afterwards. The price I got from a local place for clay was $800 per truckload ! Would it be wiser to spend the money on a truckload of bentonite if plan A doesn’t work? Is there anything I should put in the bottom of the hole once I get it dug out? Like concrete or limestone shavings before I back fill with fresh dirt ( I think it’s what they call Red Select soil here in Oklahoma) I’m worried once the pond is a full 8 or 9 ft deep the pressure may cause the leak to form again. I’m sorry for the stupid questions but really I just don’t know what I’m doing and I can’t afford outside help. But, my wife and I have a dream of this beautiful pond with a fountain , fish, ducks ,and a row boat. It may break me but I can’t give up! 😁

I'd put the dirt that you CAN pack in the hole about 8" deep, then pack the snot out of it with the bucket on the excavator, keep repeating the process. If you really wanted to compact it good, I believe there are sheepsfoot rollers that you can get to go on the excavator in place of the bucket. Roll it back and forth with down pressure.

You can't put a thicker layer down THEN try to compact it because you won't transfer the PSI of the compacter to the bottom of thicker dirt.

This sounds like a situation that would benefit from polymer application. Feel free to reach out anytime Marty - I'm a volunteer here and help guys seal ponds nationwide - my time is free to my Pond Boss forum family. Happy to help however I can.

[email protected]