Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? Wildlife pond leaking - need inexpensive liner

My little wildlife pond won't hold water, there is just too much limestone and sand in the soil. It rains and there is a couple foot of water in it, then 2 weeks later it's empty. This pond is primarily just for wildlife, but if I could get it to hold I would use it to raise minnows to transfer to the main pond.

It's only 35' x 35' and about 5.5' deep, so I would need something around a 45' x 45' or so liner. I'm not finding anything under $600 or so. Are there any cheaper alternatives for a wildlife pond like this where it wouldn't be a huge problem if the liner eventually failed? I hate to spend so much money on a little wildlife pond like this.

I don't have any experience with using a pond liner, but you might be able to save a few bucks by looking on e-bay. There are some pretty big ones there, and with some of them, the price includes shipping.

Have you considered bentonite? If one pound per square foot fixes you issue you could get by for less than $300. I assumed that you have 2000 sq feet and 50 pounds of Bentonite is $8 a bag. My local FS sells 50lb bags of Bentonite for $7.33 so it could be cheaper by you.

That type of soil will hold water on it's own, but it has to be compacted very well. You could also try aquablok pretty interesting product.

Thanks for the suggestions. I checked on Ebay earlier today and wasn't able to find prices lower than some other websites. I already tried bentonite. My parents had a big stack of it they weren't using so I spread it and raked it in a year ago. It seemed to help for a while but the pond never did fill up. There is just a lot of limestone rock and sand in the soil. I'm going to do some research on aquablock.

How much bentonite did you use? over the whole pond? Did you wet it and compacted it? My suggestion above was for a pound of bentonite per square foot of bottom area. From what I have seen this is the minimum and more could be required. Best to do a test of your soil in the bottom of a 5 gallon bucket with holes in it. Basically put a couple of small holes in the bottom of a 5 gallon bucket, add enough of your soil to be roughly 4" deep in the bucket and add a pound of bentonite well mixed with the soil. Pack this into the bottom of the bucket. Add water to almost fill the bucket. Stand back and see if it leaks. It may leak at first and stop over time so wait a while before drawing conslusions. If it leaks over time add more bentointe and repeat. Once you get it to stop leaking you have determined how much bentonite you need for that area, just multiple this out for your pond area to get the total bentonite needed.

A little less than 1000 lbs of bentonite. I spread it and raked it into the soil by hand. I didn't buy any, this was just a stack of bagged bentonite at my parents farm they weren't doing anything with so I brought it to my place. Might just break down and get a liner. I deer hunt near this little pond too and really want it to hold water permanently.

Is this one of the famous "hand-dug" ponds that Eric in TN has made so wildly popular?

"hand-dug" by me with a bulldozer

Before you try anything too expensive, you may try a cheap simple fix that I think has good odds of being successful. I'm going to try the same thing on a little bigger scale once I complete some other restoration work on an approx 1/4 acre leaking project pond.

If the soil is compacted good (which I assume it is since you say it was built with a dozer and the dam was probably walked in good in small lifts) there are probably just a few seepage paths in the bottom and/or dam of the pond allowing the water to escape. These may even just fix themselves in due time if there is enough clay sediment in the runoff feeding the pond to eventually plug the leak. To speed this process along artificially, you can go get you a couple hundred pounds of the powder form of bentonite from your nearest Farmers coop for around $25-30 or so. Then go to a hardware store and buy you a good little paint stirrer to go on a high-speed cordless electric drill. Grab you a 5-gal bucket from around the house or drop a few extra bucks at the hardware store and pick one up along with the paint mixer.

Now the fun begins...wait til you have a good rain and the pond is full, but no longer running over the spillway. Fill the 5-gal bucket about 1/2 to 2/3 of the way full with water out of the pond, add 2 or 3 cups of the bentonite powder and stir it for a couple of minutes with a high speed cordless drill and paint stirrer. This will result in a nice soupy muddy mix. Take this and splash it into your pond so it will disperse into the water as much as possible. Continue this slow and tedious process until you have added 200 or so pounds of bentonite to your pond. The bentonite will swell rapidly at first as water is added and you stir it, but will continue to swell for 24 hrs or so after that. What will happen is you will more or less create a real thin bentonite slurry within your pond. As the pond leaks, this really thin bentonite slurry will get drawn into the seepage paths, continue to swell, and plug the paths. I have tried this in the deepest part of my little project pond after it was already nearly dry and it drastically slowed the water loss in the small area that still had water in it. This is pretty much the same principle used by drillers to stop water loss through highly permeable zones . Hope this works for you and saves you a few bucks.

I say its definitely worth a shot to avoid the cost of a liner. One thing to keep in mind if you try this though...try to avoid breathing the bentonite dust. While it is a natural occurring mineral and not toxic, just like any other silica containing rock or soil dust, it is not good for your lungs.

Bentonite may still be an option if some of these other ideas don't work and you don't want to get the expensive liner. Using the measurements you gave for you pond, you would need roughly 1200 pounds of it. However, you probably want to consider something more along the lines of the 45' x 45' like what you were thinking for a liner. That would take you to about 2000 pounds. In a pond like yours with lots of sand and limestone you may have to overestimate the amount needed in order to get the best results.