Should I try and pull up the low end?

[Figgy]

Funny how it isn't until you've gone and bought a preformed pond that you learn that they are notoriously difficult to get level and that pond liners are a much better option. Anyway I wanted to add a bigger wildlife pond in my garden and I went and purchased myself the Bermuda Sands preformed pond.

This afternoon we managed to get it installed and worked hard to make sure we had it level throughout the installation. It was only later that I noticed that one corner seemed to be slightly lower. I'm now wondering whether I should try and pull up the lower end or should I just leave it? I'm going to cover the edges with stone when everything settles.

What do you think?

 

[fishin4cars]

OK, well it appears from the pic that the edges are below the level of the rest of the yard if so, I see muddy pond problems every time it rains, At the point your at right now draining and getting it where it needs to be would be to your advantage.

 

[Mmathis]

No thoughts regarding the pond, but I like your kitty cat!

 

[JohnHuff]

You can use that as your overflow end if it rains a lot in your area.

 

[Waterbug]

Ditto what Larkin said. Being low like that makes it a good candidate for floating out of the ground. Not saying it will, just that I wouldn't be surprised if it did.

If I were on site I would recommend lifting one end...but just so I could watch someone try and lift a ton of water.

Thank you for posting your experience. It can be a big help to others. Everyone thinks preforms are easier and without published experiences of other there's no chance to convince them otherwise.

 

[Figgy]

OK, well it appears from the pic that the edges are below the level of the rest of the yard if so, I see muddy pond problems every time it rains, At the point your at right now draining and getting it where it needs to be would be to your advantage.

The plan is to create a soil border around the pond which will slope away and I'll be stocking the border with grasses and heathers.

Ditto what Larkin said. Being low like that makes it a good candidate for floating out of the ground. Not saying it will, just that I wouldn't be surprised if it did.

If I were on site I would recommend lifting one end...but just so I could watch someone try and lift a ton of water.

Thank you for posting your experience. It can be a big help to others. Everyone thinks preforms are easier and without published experiences of other there's no chance to convince them otherwise.

When you say floating, do you mean the whole pond will actually lift right out of the hole? What's the best way of preventing this?

Yeah, I stupidly thought I'd be able to just lift that corner, overlooked the weight thing lol.

 

[addy1]

lol I did the two preformed my honey bought me as a pressie. NEVER again NEVER again will I do a preform, what a pita!
If your ground holds water and you don't slope the ground away from the edge of the pond, when it rains excess water can get under the preform and as the hole fills with water behind the liner it can lift it.

So to prevent it, do a good slope away from the edge, add a french type drain to remove excess water or fill in some of the hole and make the pond slightly above ground level with the ground sloping away from the pond. One of mine is below grade, one above grade, but I have put in back sloping with paths to direct the water around the ponds and out into the back yard.

I like what they added to our back yard ponds set up, we now have 10 ponds in a way if you count the stream and deck ponds. They made a nice loop now the lotus pond is included in the big ponds circulation. But once again I would never do another preform, liners are so much easier.

 

[Waterbug]

When you say floating, do you mean the whole pond will actually lift right out of the hole?

Correct. It can happen when the pond top is below the surrounding grade. For it to happen the soil has to be clay. Water gets between the and the soil, can't drain fast enough, and the pond floats. In the case of a perform the bottom can pop up or the entire thing can pop up and float. It will only float as high as the water inside the pond is level with the ground. Generally you won't see it floating. What you'll see is it just way jacked up on one side. As the water drains from under the pond will go back down but with one side sinking more than the other. Some soil underneath will collapse. When people see it they generally can't figure out what happened. Conditions have to be right, not a common thing, but easily avoided.

What's the best way of preventing this?

When installing just make sure the water in the pond will be above the surrounding grade. You can slope soil up to the pond top so it doesn't look odd.

Yeah, I stupidly thought I'd be able to just lift that corner, overlooked the weight thing lol.

Would have been a great video.

 

[Figgy]

Where the pond is situated the ground is usually quite dry even after heavy rainfall, possibly due to the big tree at the back of our house. It rained non-stop for a few days prior to the installation and the ground didn't seem that saturated, perhaps thats a good thing?

I guess I'll find out sooner or later if it floats or not, fingers crossed it wont. I intend to add some soil and rounded pebbles to the bottom of my pond along with rocks of various sizes, hopefully this will make it much heavier.

All part of the learning curve I guess.

 

[sissy]

and every change of season they will heave some and have to be leveled.Extremely dry conditions can effect it also and then when you get rain it can happen again ,it is a never ending circle of leveling after 2 years of mine I gave up .

 

[buckry]

I would definitely make this right. I found the easiest way to level my preformed pond was to life it up and dump golf ball sized rocks down there then lower the pond until it was right. The weight of the water pushed the rocks into the soil and made a nice solid foundation. Then once I got it perfect I lifed it again and put soil in. It was really easy and did a great job.

 

[fishin4cars]

I would definitely make this right. I found the easiest way to level my preformed pond was to life it up and dump golf ball sized rocks down there then lower the pond until it was right. The weight of the water pushed the rocks into the soil and made a nice solid foundation. Then once I got it perfect I lifed it again and put soil in. It was really easy and did a great job.

Seriously? Not a good idea, Very easy for the rocks to go the other direction and punch a hole in the pond, I would NEVER recommend adding rocks behind any liner, even smooth ones can cause serious issues. If it was me, I would drain, lift it out add sand and get it right now. Far easier to do it now then when you have it all stocked and decorated and find you HAVE to make that adjustment.

 

[Figgy]

I did put a good amount of sand in the bottom during the installation, perhaps I didn't use enough. Is it worth letting it settle for a few days before deciding whether to go ahead and drain?

I wanted the pond to be lower than the grass so by the time I add the natural stone edging it will be in line with the top of the grass (or thereabouts).

 

[Waterbug]

Where the pond is situated the ground is usually quite dry even after heavy rainfall, possibly due to the big tree at the back of our house. It rained non-stop for a few days prior to the installation and the ground didn't seem that saturated, perhaps thats a good thing?

"Dry" soil isn't really a factor. You can dig a hole in bone most clay soil, fill it with water and it will hold water for a long time. It's a question of how fast water drains. As water gets between the liner and soil if it drains away faster than it's added there's no problem. Added faster than drains the hole fills to ground water and the pond floats. Keep in mind that the total volume of water needed to "fill" the hole can be very small because the hole is already almost completely filled with the pond. To start the floating process could take just a gal of water. Once the pond floats a tiny bit the gap at the top widens and allows more water in faster.

Most common floating happens with rain. But it's also happens with leaks, like around waterfalls normally.

 

[Waterbug]

I did put a good amount of sand in the bottom during the installation, perhaps I didn't use enough. Is it worth letting it settle for a few days before deciding whether to go ahead and drain?

No benefit to waiting.

I wanted the pond to be lower than the grass so by the time I add the natural stone edging it will be in line with the top of the grass (or thereabouts).

You can still do this, and it's a good effect. Say the water level in the pond is normally 2" below the top...that means the top of the pond should be 3-4" above the surrounding grade. If you slope soil from the top of the pond back down to grade say over 1 or 2 feet you hopefully won't really notice the pond is high.

Keep in mind you only need one area of the pond to be above grade. So you could add soil to raise the grade all around the pond except for one side, like the far side. If that makes sense to you. I've exaggerated the grade differences to make the picture more clear. That lower part only needs to be a couple of inches.