liner balloning

[Bart]

I have a goldfish pond about 5000 gal and its about 34" deep. Oval shaped. It has been in service for about 3 yrs. A couple of days ago I noticed that the liner was balloning like it had a leak in the liner and water was entering behind. I dropped the level down to where I thought the leak might be, about 14". I then pulled back the liner so I could get a pump behind and pump out the water. I could not detect where there was a leak, so I started pumping out the water from behind the liner and back into the pond itself. I pumped several hours but could not see where the balloning had changed. My idea was that if there was a leak in the liner, then pumping the water back into the pond would not change the level. But if the balloning was caused from surface water getting in behind the liner, then pumping the water from behind the liner and back into the pond would cause the water level to rise in the pond. Well the next morning there was a rise of about an inch in the pond. We have had quite a bit of rain lately and in the past but I have never seen this before. The ground around the pond is very soggy in places. The sides have been built up around the edge to about 6" above the ground level.
So my questions are; Are my thoughts correct on what is happening here?
What can be done about this if anything?
Will this cause the wall to cave in?
Another thought is that the liner will just fall back into place once the rain stops and dryer weather sets in.
I would appeciate any ideas or help on this subject.
Thanks
Bart
Buna Tx

 

[Dave 54]

Sometimes you find that the water table is that saturated that if the pond is bellow it it will cause your liner to raise up.
I've seen photos of liners sticking up in the middle of the pond like a whales back with all the water pushed out of the ponds apart from at the sides .
The only thing you can do is to rebuild the pond above the water table or like ourselves have a free standing pond.
The quickest way to do this would be to buid the pond with railway sleepers staked to the ground then attatch the liner to it see link about this problem :-

http://www.mpks.org/faq/ans74.shtml

Best of luck

rgrds

Dave

 

[sissy]

could be water table like dave said and if you got cold temps also .It happens in sandy soil and heavy clay soil .I had it happen near my one water fall the first year i put the pond in .I thought the pond was leaking but we had lots of rain for a month and after it all dried out and got back to normal it was fine and nothing has happened again .You should measure your water level and then measure the water you pump out in 5 gallon buckets and if your level does not change then it is ground water .You may not want to put that water back in the pond anyway as you have no clue what could be in it .Could be fertilizers and all kinds of chemicals in it .Is the liner pvc or or is it 45 mil thick .Remember also liner parts that are exposed to extreme heat may break down or crack .PVC liners are more prone to that .

 

[Dave 54]

Good sound advice sissy that way you'll soon tell if you have this problem or not,I must admit though that the first time I saw this I was flummoxed for a while until I figured it out.
Our own pond sits above everything with only the bottom drain in the ground, however I doubt we would ever had got this problem ourselves as we are on a hillside.
But with all the rain people seem to be getting nowadays I'm supprise we are not seeing more of this problem.
Here in the UK when building the pond we lost almost two years of build time to the damn rain, this was caused by the jet stream moving in over the UK and Parking over the South of the county.
It did this in 2010 and 2012 leaving us only a month to do anything, well for Jeff our neighbour doing it as he's done the build we supplied the coffee and sandwiches lol

rgrds

Dave

 

[sissy]

My pond sits 2 feet off the the ground on one side but only 6 inches above the sidewalk on the other side .The waterfall tank on the one side is the one where the leak was and it did cave in and came from a bad storm we had and the gutter pipe came loose from the underground pipe that led it out to the yard .That side of the pond was 2 feet off the ground and drain for pond over flow is on that side and all that came together and cause my problem .last pic you can see the 150 gallon stock tank I have there now .The bulge happened before I put the stock tank there .The pond is just around 2 feet underground

 

[taherrmann4]

Here are some topics on the liner ballooning. You need find a way to get the water from out from underneath the liner even during periods of heavy rain. I ran a pipe down the side of my pond about 12: down, just a regular pvc with an open end. The other end runs out about 10' away from my pond. What I have found to happen is during heavy rains any water that gets under the liner is pushed up to this pipe and then the water has an easy way out. The water finds the path of least resistance. This has worked for several years now. I also put down a few large rocks in the bottom to also assist in keeping the liner down, maybe six rocks or so.
https://www.gardenpondforum.com/topic/5696-water-behind-liner/?hl=ballooning
https://www.gardenpondforum.com/topic/6089-my-worst-nightmare/?hl=ballooning

 

[DrCase]

I found if you have a pond 6" above flood level
You wont have any liner float ups if you have more water in the pond than around it.
if the heavy rains get up to your pond level, you need to raise your pond 6" above the high water mark
Any thing you can do to send the water past your pond will help , a pipe like Tmanns or a dry creek in to my neighbors yards like me , its the natural drainage
Bart , have you checked to make sure your line from your pump to your filter is not leaking, ?

 

[Bart]

Thank you very much for the help and ideas. I believe I understand what is happening now. If the water level in the pond is lower than the standing water surrounding the pond then there is a good chance the liner will ballon. So I need to raise the water lever in the pond. Since the land around here is all flat, if I install drains there is no place for the water to drain to.
I have checked and double checked and there is no leaks around any of the lines or filters.
Thanks again
Bart

 

[gardengimp]

Bart, many places in florida an elevation for water runoff is an inch. I dug a French drain to carry roof water away from my pond. You could look into building some French drains or sloughs to direct the water into a rain garden and away from your pond.

http://www.gardeningsolutions.ifas....theme_and_specialty_gardens/rain_gardens.html

I always thought a rain garden below grade from a pond and connected by a rock ridge would look really neat.

 

[sissy]

I like that idea .I have an area I did with rocks from my property and there is an underground tank there where 2 of my gutters go to and I pump from it to water my yard .But rocks from my yard there to fill in low spot are around 3 feet deep in the center .I have a fake stream also with a bridge .I dug it out and put my rain drainage pipe in it for my gutter to get the right slope and then put stone in it.The drainage and trellis bridge .The basket is on top of where the pipe comes up from the underground tank .

 

[Philphine]

because i built my pond without knowing what i was doing mine does it fairly often, or more often than i'd like. i'm not going to change it though. what i ended up doing is taking my first small pump from when i first started playing with the pond idea, and put it under the liner but over the underlayment at the spot where it usually starts. it'd be better if i could get it to work automaticly, but if we get a heavy, or day long rain i just plug it in. if i catch it in time the liner stays down. if i'm late and it's already rising it helps bring it down faster than waiting for the water under it to go down on it's own.

the underlayment seems to be filtering the water a bit. i run it back into the pond (there's a lowspot for overflow at the far end to get rid of the extra water) and it looks pretty clear. if i push on the bubble though, like i'm trying to help it, the water gets muddy looking so i let it work on it's own. i did this last winter and we had a fairly dry warm season last year. i used it a handful of times (i'm always worried it might burn out or something if i don't turn it off in time, or on too soon) and i'm pretty happy with it. hopefully it will work out as well during a wetter season.

another thing i tried before i put the pump under the liner, was a old garden hose in the same spot. i ran it along the side of the pond and along the little dry creekbed like deal the pond overflow is connected to, and down to a drainage ditch behind the house. having the end lower siphoned water out some, but i had to prime it first, and it was pretty slow. plus if a bubble had started already, just getting rid of the ground water lowered the water level in the pond once the bubble was gone, so pumping it into the pond worked out better. at some point i mean to add a Y connection off the pump outlet and see if i can get both methods to work