Pond Boss Forums INTRO Questions & Observations Building 1 Acre Pond (High Water Table)

The only issue with using a clay liner with the high water table is getting and keeping the clay the correct moisture content so that it can be properly compacted with a sheepsfoot roller in multiple lifts. (total clay thickness should be 18"-24". In your situation with the high water table that will be difficult to do but I don't think it would be impossible. Dig a deeper "sump" and have the water seep to that area while you are placing and compacting the clay. Keep the water pumped out of the sump and make the sump the last thing in the pond basin that is sealed.

With a membrane liner, that should be covered 12"+ with dirt anyway, so that might be enough to keep it from ballooning until you get water in it. The dirt over the liner doesn't have to be compacted, just put in place and have the slope of the pond sides gradual enough that the dirt won't slough off and slide to the bottom of the pond when the water is added.

Once the water level in the pond is higher than the water level in the surrounding ground, there will be no ballooning because of the higher water pressure in the pond vs. the water pressure in the dirt.

The "tile" suggestion while you put dirt over the liner will work great. Have the tile terminate in a pit that is deeper than the total depth of the tile under the pond and keep that pumped out while the work is being done to cover the liner. Then you can pull the pump and fill the pit.

Using a well to keep the pond full will work too, but the well has to pump more gph than the pond leaks, and you have to be willing to pay the monthly electric bill.

I have a ground water pond that can have the water level drop 9 feet lower than the normal "full pool" water level. It will leak more than 20+ GPM at full pool once the water table starts to drop. .