Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? Read the book now ??

It's hard to combat ground water unless you build a sump and keep it pumped out as you compact the pond bottom. Mike Otto would tell you to keep pumping and at the last, after everything is like you want, pump the sump empty and quickly backfill and seal with clay to stop water from flowing in. Just like Scott said above, ground water seepage will dictate your water level. If you have a large enough watershed, you can seal the pond, it will fill with rainwater and runoff and you can have the water level where you want it, subject to droughts and floods, evaporation compared to input.