Pond Boss Forums POND CONSTRUCTION Building a dam Installing PVC liner in just the dam

I'm excavating a small pond (~3000 Sqft surface area) in a steep and deep "holler" on my property. Intent is to dam up the end to start catching water instead of watching it erode my property. He dug down deep enough to start hitting bouncy/springy stuff he said was the water table.

We are on the Arkansas river so mostly sandy loam as far down as we've dug. Bringing in bazillion yards of clay to this area is out of the question. Question is can I install a liner on the inside of the dam left to right, top to bottom (buried below pond bottom) and expect it to hold? Or possibly a liner *plus* polymer? I think it's maybe 8 ft deep as planned. Plan C is a full liner.

I'll be talking to TJ early next week about the same question but wanted addition input as well.


Steve
Broken Arrow, OK

It's generally considered necessary for a liner to be installed over the entirety of a pond's bottom - a partial liner can't be sealed tightly to the unsealed portion of the pond, hence leaks occur.

Understood, thanks. I've read here that if I did line the whole thing, I'd want to backfill to protect the liner with a layer of soil.

That leads me to two concerns:

1. I walked around it and determined that I can build an anchor trench for the tarp, but much of the perimeter is very steep and would not hold material inside the liner on the steep walls (the tarp would be exposed in the water).
2. How do you get the backfill cover material onto the tarp with a skid loader without damaging the liner?



thanks!

You're going to have to remove some of the trees and taper the banks back a bit. The problem with the trees is that all the leaves that they drop in the pond will generate muck that will accumulate quickly.

But backfill over the liner under the water line would still slide down the wall wouldn't it? I'm just not sure I can taper it back enough to have a more gentle slope. I've seen liner install drawings showiing a "curb" or "speed bump" to give the dirt something to settle on under the water. Also don't see how to backfill with material driving the skidloader on the tarp without damaging it.

On the trees issue...I love my trees but know it will be a chore to keep them off the bottom. I'm looking forward to being a pool-boy with a skimming basket several days a year.

Here are the best instructions I have seen regarding how to build the slopes and speed bumps to hold the soil.

Covering & Protecting a Pond Liner

They don't specifically address it in the video, but it does appear in the background that they are covering the liner by hand after the cover soil is stockpiled right at the edge of the pond.

I have also seen a video of covering using heavy equipment (but I couldn't find it). In my recollection, they just built out a soil cover on top of the liner from their stockpile. The equipment only traversed the liner where it had 4-6" of soil in place and then they built out ahead of their safe travel zones.

If you decide to go with the liner, I would determine which manufacturer you are going to purchase from. Then call them and ask them to explain the proper installation procedures for your conditions.

Good luck on your project!

To cover with a skid loader, you dump the dirt on top of the liner as you drive onto it. So you are always driving on the dirt, not on the liner. Don't turn and "skid" the tracks on the liner, in and out, in and out, if done with equipment. If an excavator is on site, that can be used to put the dirt on the liner and the skid steer can be used to smooth it after the excavator places it. If the bucket on the excavator is smooth (no teeth) the operator can smooth it as far as they can reach.

BTL liners have a woven fabric liner that is very lightweight compared to PVC liners and it is VERY tough. It's hard to get a knife into it to cut it. A client made a small wildlife watering hole with it, maybe 30 feet across. He did everything with a Kubota compact tractor with FEL, I believe it had around 30 hp. It's been in place (in Arkansas) for IIRC 5-7 years and still no holes in it, even though the hogs have been rooting around in the wet edges. Him and his wife installed it, and they were in their late 60's when they installed it.

Wow very cool thanks for the good info!

Thanks FishinRod I'll definitely check this out. I want to do it right.