Water behind liner

[Bart]

Hello to everyone. I am new to this forum although I have read the questions and replies. I live in SE Texas close to the Gulf so I am not a lot above sea level so we do have a problem with big rains draining off. This leads up to my situation. I have built a new pond. I dug it back in Oct last year. I installed the liner and filled it with water and left it like that until winter was over. It is oval in shape 15' x 20'. Now I have my water fall in service and fish are swimming around. Here is the situation. I noticed that my liner was bulging out or ballooning at a couple of places on the sides. I assume that this caused from water behind the liner. We have had quite a bit of rain lately and like I said it drains off very slow. Today I notice another place that is ballooning and also I had to get in the water today to clean out the drain from some leaves and I noticed the bottom is ballooning also. Just how serious is this problem and what can I do about it. I was thinking about trying to pull the liner up to tighten it up but thought it would just fill back up with water. Does anyone have any ideas on how bad this is or what I can do about it.
Thanks
Bart

 

[DrDave]

Can you post some photos of the liner problem?

 

[Bart]

I will try to take some pics tomorrow and try to post them

 

[koiguy1969]

due to my own forgetfulness,and getting side tracked i managed to allow in the neighborhood of 200 - 300 gallons of water under my liner i wiggled a garden hose down in between the liner and ground as far as i could. it didnt make it all the way down but the weight of the water pushed the water to the outside and it created a seal around the hose. i bought a $10.00 drill motor operated pump and got the water out with little trouble

 

[Bart]

Thanks Koiguy, I have one of those pumps. I think I will try that tomorrow.

 

[addy1]

You might want to build some french drains, or put make the ground higher where the water is collecting or going to your pond, to path it around your pond. That will keep it from happening again.

 

[DrCase]

If you can raise your ponds edge higher than the ground around it. it should have more pressure in side the pond to keep the liner in place

 

[taherrmann4]

Bart, I have the same problem after very heavy rains. If my trees and landscaping were not grown up so much I would put in a french drain around the pond but I do not want to destroy the landscaping. So what I have done is I put several decent size rocks around the perimeter of the pond on the bottom as well as a few throughout the middle. I still get some water under the liner but it drains off in a few days. Before I put the rocks in I used my pond vac and sucked it out under the liner, not a practical way but at the time it worked. I thought about putting in a perforated dran pipe in one end of the pond rather than all the way around, digging a hole straight down as close to the side of the pond as possible and then ot to the yard. The reason I think this may work is that when I use my pond vac to suck the water out I only put it in one area of the pond and it takes all the water out from underneath. Water will go where there is least resistance so that is why I think it will work, but I am by no means an engineer. I am going to try it this year. Your problem may be different than mine because you are so close to sea level and I just didn't plan the drainage around the pond right in the first place. Maybe you could install a sump pump pit with french drains running into it?

Let us know what you do and if it works..

 

[taherrmann4]

This should have been my sign 6 years ago when I built it, that's probably what my dog was thinking.

 

[Bart]

Oh wow! That doesn't look good at all. Were you able to save it?

 

[sissy]

sad when you think the dog is smarter than you.He just wanted to have the last laugh taherrmann4 .You probably dug up all the bones and things he buried too LOL

 

[Bart]

Just an update on my problem. I took Koiguy's suggestion and used a drill operated pump that I all ready had and pumped out all the water. I also noticed where the water was coming in at. It was running down between the liner and earth. So I had some liner material left over so I cut some strips about 24" wide. I then put down more sand around the perimeter of the pond making it higher than the surrounding yard and slanted it to the outside. I then laid down the liner and place one edge under the top layer of cap stones and laid the rest down the slant. Over that I reinstalled the walkway I had built. This will divert the water away from the edge of the pond and down the slant and into the yard. I think this should take care of this problem. If not I will try something else.
Thanks again

 

[ginger_biscuit69]

hey,

surface runoff is not your problem, groundwater is.

Short of concreting and draining large areas around your property, groundwater levels will stay the same.

What was previously meant, is getting the actual pond water surface level ABOVE ground level. For every 1cm/m^2 of depth added above ground, you will get 100kg/m^2 added pressure to the pond floor.

Theoretically just a few cm (such as a brick, or block as you yanks use - suffice i should have used inch/feet and pounds/ouces for this haha), will create a higher pressure on the ground 'pushing' the liner down with higher pressure than the ground water will exert upward.

Think of it as keeping a boat afloat in reverse, your liner is the boat hull and you want it to sink!

 

[addy1]

Great bart, hope that fixes your problem.

My pond is at the bottom of a steep sloped yard, During the build I made sure to make the uphill side slope back away from the pond. It did not take much of a slope to send the water around the pond. Also added some dug in shallow pits and place gravel in them, mini french drains. So far have not had any issues, and we have had some heavy rains.

Your fix may have taken care of it. Next rain go out with a umbrella and walk the pond check for any running water going where you don't want it too. I did that quite a few times right after I had the pond lined and sloped to make sure I had not missed a path the water decided it wanted to take, where I did not want it to go.