Pond Boss Forums POND CONSTRUCTION Selecting a site New pond questions. Water table/sand issues

I have a groundwater pond. 11' of sand on top of 1' of clay, then another 6' of sand on top of at least 4' of clay. (when we renovated the pond we dug down to 22' below grade and it was solid blue clay there). In a wet spring, water will sit on top of the ground until early June.

What I've found over the years is that the groundwater level will fluctuate up to 6'. During a wet year, the pond will drop about 3'. In a dry year, double that.

If I were to do it all over again, even though I put the pond in a wet spot, I would dig the pond large enough so I could line the whole pond basin with 6" lifts of clay, compacting each lift with the next one so I would end up with at least 2' of compacted clay.

I can pump 25 gpm of water into the pond and it will not reach full pool during drier years. I've never run the well during a wet year, saving on energy costs and just figuring that a 3' drop in water level was normal. If I had my druthers, I would rather have the pond full at all times vs. fluctuate in water level.

My neighbors, who have lived here about 10 years longer than I have, said that with me having the pond, they see less flooding in their back yard during wet times of the year. So, when you dig your pond, you may not see the water standing on top of the ground like you do now. The way my pond is designed, it will receive surface (top of ground) water runoff.

In hindsight, if I would have only dug the pond 11' deep so I didn't punch through the level of clay, I would end up with a pond that at least 6 months out of the year would be only 5' deep at the most. That depth is not conductive to having fish survive a long and hard winter like we just had without intensive management methods. I dug the pond down to the 22' deep mark, and normally go through a winter with 14' of water in the deepest part of the pond.