Pond Boss Forums INTRO Questions & Observations WATER UNDER POND LINER...HOW???

So I installed a huge 80ft round 6 foot deep pond/lake liner in my pond this summer. It has a slow trickle of a creek that feeds it. I filled the pond with water and its holding great. I have a small trickle of a creek that feeds it..but at the point of where the creek enters the pond is tricky. Ive built a little in-creek/pre-pond before is spills into the lined pond. That pond isnt lined. The pre-pond is always full...yet its not full ENOUGH to spill over into the lined pond. (It does when it rains). But WHERE is the trickle water going? I thought it might be going UNDER the liner...but it isnt. Ive felt around in there... Its not bubbling up. The weight of the water is holding it down. But WHERE is the water going? Very odd?

Maybe its leaking into the twilite zone?

If I understand you right you're saying a trickle of water is going into the pre-pond but not raising the level of the pre-pond eough to overflow into the largerer lined pond --so it has to be going somewhere? Sounds to me like it's seeping down somewhere, whether it be the bottom of the pre-pond or seeping out sideways from the pre-pond and down.

You may have just enough seepage to keep the pre-pond water depth at equilibrium. All soils seep a little regardless of how much clay there is. Some just seep more than others. You could also have a sand vein or less impervious layer just under the bottom or sides of your pre-pond that the water is seeping into.

On my property I have so much clay in the soil you could make pottery out of it! However that doesn't mean there isn't a sand vein somwhere and I've seen them as small as a few inches in diameter.

With creek so close there is a good chance there is some silt, sand, gravel, etc. deposited by that creek that allows water to seep in.

Can you line the pre-pond?

That's what I will probebly do next summer. That's my problem...where the lip of the liner and the bottom of the bottom of the pre-pond meet. That transition is difficult at best. The water gets full...but it peters out and it doesnt have enough to spill over. You could be right about that sand vein. That would explain it.

Well, I'm no expert but, if you felt the need to line your main pond then it seems logical that you had reason to believe your soil might leak so, your pre-pond is bound to have the same soil with the same problems. Water weighs something and creates pressure so, maybe it just filled up to the point where the pressure is forcing your pre-pond water to find a place to leak.

Just my guess...

Yeah I thought that too... Yeah...I put that liner in there because I had a leak in my pond. I actually knew were one of the leaks was..because I could see it coming out of the dam. Once I installed the liner....that leak wasnt there anymore. Yet the water is still coming in. It just doesnt come out (in a location where I can see it)

Very odd.

The pre pond must have a natural outflow that is substantially lower than the intended channel, I wonder, if you have an available supply of sodium bentonite clay, that could be stomped into the area to force the water level up to the intended outflow

Regards, andy
http://www.flickr.com/photos/21940871@N06/

The prepond's bottom is part lined from the exsesive amount of liner I had for the lined pond. The sides/wall of the prepond is not lined. It does however had a heavy about of blue clay on it. I will have to get in there with the big cans of spray foam. Not the stuff you get at the pond store....the bb-q tank size spray foam you get out of the GRAINGER catalog. That stuff sets up quick....and theres plenty of it. That should stop it.