water table?

[ohfortunate1]

morning folks, i have taken the bull by the horns and decided to enlarge my pond currently 11x9x3 i am making it 11x9x6 and while i was digging out yesterday i got down to the desired depth in 1 corner so i new the level to work to unfortunately at this point water started to dribble into the hole through the sand and it has risen to hieght of about 9inches ? i'm assuming it is the water table as it hasn't risen anymore over night.
my delemma is i did intend using a liner "already purchased" but before i go anyfurther with the dig what can i do about the water ingress do i back fill with the soil removed to the depth of water or do i drop a cpl of bags of rapid set concrete in there and continue digging to a shallower depth?

any advice would be great

cheers Ian

 

[ohfortunate1]

another thing before i go would a bottom drain work if i connected an external pump to it as my filters are above ground and havent the space to sink them ?

 

[Waterbug]

Back filling wouldn't really change anything, and adding concrete sure wouldn't (not sure what the thinking was there) because the water table level you're seeing is only what it is today. Next week could be lower or higher. In NY our water table would be above ground in areas for parts of the year while in late summer could be 15' down.

The trick is to make sure the water level in the pond is at least a couple of inches above grade. If water in the pond is below ground table level the liner can float up. That probably means some grading to make it look right, but you have a lot of dirt to use.

You could consider making a raised pond by building a wall maybe 18" high. That eliminates the issue for sure and you don't have to dig as deep. Digging mud isn't fun.

If you dig deeper you'll need to keep pumping it out as you dig, You can lay down some carpet to help keep you out of the mud, or bring in a backhoe. If real sandy and water comes in too fast a backhoe is about the only option. The liner, assuming something good like EPDM (not thin PVC) can normally be laid with water in the pit with no underlayment, or pump it out first and put down the underlayment. If the underlayment floats you can put some sand on top. Filling the liner with water will push back the ground water.

 

[Waterbug]

another thing before i go would a bottom drain work if i connected an external pump to it as my filters are above ground and havent the space to sink them ?

No problem.

The only thing you'd have to be be careful of is you could never completely drain the pond for cleaning. Not a big issue imo, but you don't want surprises.

 

[ohfortunate1]

ty waterbug for the advice my pond is about 6 - 8 inches above the natural level of my garden so hopefully i should have no problems, but the rest of the dig certainly wont be going as deep as i intended .ty again Ian

 

[Jason]

I had the same problem with my pond but a lot worse... I can't dig past 2ft ANYTIME of the year unless we had a drought (Yeah right!) I dug my pond at the end of a "Dry Spell" (which was about 1 month with no rain) and I live right between swamp land and the coast of the Gulf of Mexico. I never heard of the "Floating Liner" problem until after I built and filled the pond. My Small 500 gallon pond whole bottom is river rock and boulders on the side ledges to hide liner. We had a Huge Rain last month at 13" in a weeks time! One day the water level on the ground was the same level as the top of my Pond (which is raised on the edge 3-4" from the ground for more water depth) I thought for sure either my Liner would float up or my fish would swim in the unknown but neither happened except my Florida room flooded. Im not saying your liner won't float, but I think the reason mine did not was because I have so much rock weight on the liner that it would not budge but rather water just filling over it, so if you are worried about that I would weigh it down with the natural look of rock and hopefully it will help