I dug a .40 acre pond on my property 8 months ago. For the first several months (Spring) we got a lot of rain but the pond seemed to lose quite a bit of water to seepage. It was roughly half full in May. Then we had a Summer drought and the pond lost a lot of water to evaporation and probably some to seepage. It started to rain regularly again in July, and last week the pond was at roughly the same level it was last Spring. (half full)
In the last 2 days we've gotten heavy rains so the pond should have more water in it now than ever. Since the weather has cooled off this Fall the water level is not dropping any between rains, so I guess the pond has sealed itself. I'm expecting it to completely fill this winter. I dug the pond myself and it might have sealed faster if the soil were properly compacted by someone who knew what they were doing. It's taking a while to fill because it doesn't have as much watershed as it should. It seems like it's taken 6 months or so to seal and quit seeping.
Good luck!
Eric
