Since someone started the rock thing.....

[PondJoy]

I understand about the hazards of having rock in your pond, but I have mine lined with rock here because the ground water keeps pushing the liner up if the rocks aren't there.  Trust me when I say that the ground water is stronger than the pressure of the water in the pond.  This part of the state is well known for that problem.  So how in the world do you deal with that problem if you don't want rock?

I do have to do a little more maintenance with the rock, but it's not too bad....anyway just curious.

[Koi Boi]

You might try checking any local dealer of fiberglass swimming pools or in ground liner swimming pools.  Ground water problems have surely been dealt with by them.

Paul 

[-Greg-]

Back when I was doing allot of research in building my pond, I ran into plenty of threads over on koiphen.com that delt with groundwater and low water tables. They ranged from simple check valve installed into your liner (lets the groundwater into your pond), to french drains installed under your liner going to a sump pit, where a sump pump with a float switch pumps out the water to a drain. Also, there were some who chose to utilize the groundwater/low water table to have a natural "mud" pond.

If you get a chance, check out a couple of the threads over there under the "pond construction and filtration" category, or, in the search window, type in "groundwater".

Greg

[PondJoy]

Thanks for your replies...I cleaned the pond yesterday and I have to admit that even though the rocks look great, it would have been much easier without them!  I'll check out the info you suggested for future plans.

[mascot]

I was wondering....instead of rocks, why not use large pieces of slate rock in the bottom?  They're heavy, and since they're flat they will make it easier to clean the bottom of the pond (providing the pond is flat bottomed).

I've had the bubbled up liner two years in a row now, and I know that the ground under the liner doesn't drain well.  I have underground drains in the back yard and the water will pool up until it reaches the drains.

This was the first year when I was planning the pond....and before the underground drains....this water sat for a few days.  by the way...the picture was taken before I started digging, so the water is only a few inches deep.  It did help me quite a bit to make sure that my berm was level though!   

[PondJoy]

That's an idea.  I did try using bigger rocks, but I like the idea of large flat ones.  I like the way you did your walkway.  What did you plant in the empty spaces?

[mascot]

That's an idea.  I did try using bigger rocks, but I like the idea of large flat ones.  I like the way you did your walkway.  What did you plant in the empty spaces?

Since that picture was the first fall that I was there in a brand new home, I didn't have alot going on.  Here's what the area looked like last summer:

[Goodkarma]

I don't post often but I have first hand experience with this.  The simple way to not have a liner bubble is to build your pond to be raised a few inches above ground level.  Most ponds are built at ground level but the water level is usually at least a few inches lower.  Water rises to it's own level- a physics fact.  So when there is heavy rains, and water saturates the whole ground, if the water level of the pond is not at ground level, the water pressure from the ground water pushes up the pond liner.  The pond water then becomes displaced, spilling out of the pond, .......meaning less water in the pond...........so ground water tries to fill in the gap again.......causing more liner bubbling.


Here is a thread from another forum showing the type of storms and how ground water is a frequent problem for most of our yards in my neighborhood.  But the liner never bubbles on the pond which is raised about 4 inches.


http://forums2.gardenweb.com/forums/load/ponds/gal0817354431310.html?6

Regards,

Lisa

[mascot]

Not to argue your point, but I honestly think that the problem is not the height of the water level but the fact that I have enabled the water to get under the liner because of what I did, rather than having a way of diverting the water away from the pond.  Looking at your pictures, I can see there's a lot of standing water, but it looks like it can't get under your liner because of how you built the pond.  Water can very easily get under the edge of my line.

The water's getting under the liner at the edges because I didn't bury the edge of the liner, and the ground level around the pond itself is not "high ground".  The water isn't forced away from the liner, it just doesn't have anywhere else to go but under it.  It was a very poor oversight on my part, that I know, and the ground is so hard under the liner (rock, dg, etc) that the water doesn't get absorbed very quick.  Since the water flowed towards the pond and under the edge of the liner, it basically filled up because of gravity!  I don't think that I'm getting the bubble because of the water table being saturated, but because water flows "downhill" and despite my efforts to raise the ground up around the edges, I still have a problem because there is no resistance keeping the water from flowing under it.

I have some extra strips of liner and I may try to bury it under the ground level so the water doesn't get under the pond so easily. 

Incidentally, I never have overflow issues with the pond because I built a drain at a low spot on the edge of the pond (kind of the way your sinks/tubs have an overflow drain so you don't flood your house).  When the water level gets too high (like leaving the garden hose on too long), instead of overflowing the pond it drains underground and out to the street.  Water only gets to this drain when the level inside the pond reaches the low spot on the liner.

My "mistake" is on the left...the way it should have been done on the the right (20/20 hindsight)

[Otter]

If the water level in the pond were above ground, well, above the highest flood level, actually, I don't think water would be able to get behind the liner in the first place.  The pond water would exert more pressure than the ground water, and hence the ground water would not be able to force the liner inward.

Incidentally, I never have overflow issues with the pond because I built a drain at a low spot on the edge of the pond (kind of the way your sinks/tubs have an overflow drain so you don't flood your house).  When the water level gets too high (like leaving the garden hose on too long), instead of overflowing the pond it drains underground and out to the street.  Water only gets to this drain when the level inside the pond reaches the low spot on the liner.

If that drain pipe runs a few inches below the water line, you could connect it to a small dry well near the pond.  As long as the water in the pond is above the the highest point of your drain pipe, the weight of the water in the pond should force the water behind the liner into the pipe.  If you still get bubbles on the far side, a slotted drainage pipe running around the perimeter of the pond would probably be enough to get the water round to the drain.  This might not be as good as the french drain you'd have built if you were thinking about this before you built the pond, but it might be good enough, and it wouldn't require you to make any major changes.

[frloplady]

That's an idea.  I did try using bigger rocks, but I like the idea of large flat ones.  I like the way you did your walkway.  What did you plant in the empty spaces?

Unless they are cemented in there will be almost as much crud that gets under a flat rock because unless they are really flat and the pond bottom is smooth/flat stuff will get under them. If they are good size will be even harder to clean under.

That is a definite problem you have though!!