Pond Boss Forums POND CONSTRUCTION Soil questions Putting out 12k lbs of bentonite and installing a pump this week....

Hey everyone,

It's been a while since I checked in. Our 7-1/2 acre pond is down to almost 1 acre now. Our pond's center is basically an old ditch that we built a 400' damn to create a pond. The contractor did do some work moving dirt around in the bottom but it was fairly minor. The damn is not leaking at all and it looks like the leak is in the bottom of that ditch. So on Thursday we are going to put out 12k lbs of pelletized bentonite and we are also installing a well. The well was drilled last week and it should be finished tomorrow. It is going to run off of a small generator that I am going to hook up to a 100 gallon fuel tank. Hopefully it'll run almost a week on that and maybe get some water in it. We've put this work off long enough but if we wait much longer we are going to lose all of our fish too. The way the ditch is layed out I will be able to take my four wheeler to the edge of the ditch and put my moultree broadcast spreader at the edge of the ditch. I'll then broadcast it and measure the distance covered to determine how many lbs to put in a certain area. We are looking for 1-2lbs per sq/ft.

Wish us luck......I'm sure I'm going to be one sore guy come friday :p

-lee-

Boy that's a lot of water pressure! By my calculations, if he has a depth of 20' of water over the bentonite, it should be around 8.6psi. I could be wrong, but a cubic foot of water weighs about 62 lbs.

Good luck Lee. How old is the pond? Did it just start leaking?

Well I know that it's not a sure thing but we got a price on putting bentonite on the whole pond and to be honest it is more than we want to spend. We are fairly sure that it is going through the bottom of the ditch and it is less than probably 2 surface acres. The ditch bottom is the only part of the pond that any kind of a sandy soil content. The dirt contractor and the farm service agency thought that it would silt in and seal when we built it 2 years ago but 2 years have gone by and it has filled up numerous times with rainwater and it still falls significantly through the year. So we went and talked to the FSA and they said that this would probably be the next step. So will spread the bentonite on Thursday with a mixture of broadcasters and boats. The average depth in the ditch now is around 4' so it won't be terribly difficult to spread. The rest of the pond is bone dry so we will be able to drive a tractor up to the edge of the ditch and spread it with a broadcaster and then spread it in the middle of the ditch with a boat. Even if this doesn't seal it 100%......if it will even slow the rate of water loss it would be an improvement. We also had a well installed today and it is currently running off of a generator. According to my calculations I should be only adding around 25k gal per 12 hours so it will be a long time until I get any significant water gains. We are just trying to add a little water to help the fish make it until this winter when we will hopefully get a few good rains to help fill it up. Once that happens we will hopefully be able to maintain a certain level.

-lee-

After you put out the bentonite, can you back fill the rest of the ditch with clay, then compact? You don't need the ditch anyway. If the pond bottom is clay, and the ditch is sand....hmmmm...maybe push some clay....?
Here's another thought....25,000 gallons per 12 hours is just shy of two acre inches per day. That's significant flow rate. That's about a six month period to fill the lake, if evaporation is low, with no rainfall. That means you should be close to being able to maintain pond level all year, unless you still have a big leak.

Bob,

The ditch is currently the only area that has some water in it. I was thinking about taking our dozer and pushing some dirt in it after we put out the bentonite to help give it some type of a filter before it reached the bentonite. I don't know that just pushing dirt in the ditch will do any good without fully draining it and compacting it with a sheeps foot/vibratory tamp. I would like to keep the ditch though because it would provide a lot of structure for fishing if we could ever get it to hold water. I was thinking about maybe filling the ditch in halfway which is about 8' deep on average now. I know that I would lose some fish but hopefully not just totally wipe them out.

Our well contractor got the well installed and it wasn't putting out the volume that they claimed. They are coming tomorrow to replace the motor with a larger one because of how deep they had to dig the well. Hopefully between this and the bentonite I will be able to maintain some sort of a fairly level water pool.

-lee-

Thanks for the update. Keep us posted, yours is a real world story for others to learn.