Thanks,

Yes, I'll install the liner in the next few weeks now that the water table is bellow the deepest part of the pond.

There must be some type of hydrostatic pressure since the water flows slightly. But I'm not sure if the pressure is happening where the pond will be or up stream.

Maybe I can leave a few extra feet of liner rolled up on the edge and if I don't have enough down force I can increase the berm and still have liner to cover it.