Tony,

I am not a pond construction expert, but I am a geologist so I will try to give you some more information.

SOMETIMES bedrock will hold water. I have a thick shale bed on my farm that does hold water. However, bedrock will typically leak water by two mechanisms.

First, the rock itself may be porous and will slowly allow impounded water to leak out. Secondly, bedrock is frequently fractured or jointed, which also allows the water to leak out.

You may try filling one of your deep clay holes with water to see if it holds. Unfortunately, it would only take one leak anywhere in the pond bottom to cause your pond to lose water.

As to the clay blanket: yes, I believe one foot of clay compacted in lifts would probably seal a shallow pond. A pond liner would also provide a seal.

However, I think your pond would probably still be too shallow for your goals to be easily achieved.

Switching gears on new ideas - does your watershed to fill the pond have a significant elevation change? Do you have a creek or other available water source to fill your pond?

I am asking because you are going to have a lot of spoils when excavating a 1.5 acre pond. You can actually build up a big berm as high as you like, and finish off by lining the sides and bottom with compacted clay. You could certainly do a 10-12 foot deep pond in that fashion.

The obvious problem is that your pond will no longer fill with surface runoff water.

If you have an elevation change on your property that is greater than the height of your berm, then you could build a shallow pond upslope to catch water and then run a closed piping system to transfer the water to your primary pond. Likewise, you could also pump from a stream to fill and maintain your pond if that water was available for even part of the year. (Check your state regulations on that one.)

I hope that gives you some ideas for a workable "Plan B" for your property.

Your eyeballs on the actual ground are better than some guy on the internet. However, if you do come up with a possible viable plan, there are plenty of experts on Pond Boss that can answer more questions.

Good luck on your project!