Some favorable news on the pond. A local pond excavator stopped by my property and walked it with me. He lives in the immediate area and has built many ponds in the local soil. He looked in my test hole and immediately saw a good deal more clay than I thought I had.
Evidently, being in a gully, the soils above the Weikert shale are full of both silt and clay. Interestingly, it is laid down in successive layers; viz., there is about a four inch strip of silt, then there will be a strip of clay, then silt, then clay, and so on. He said this can go on for several feet before one hits the Weikert shale. In retrospect, it only makes sense, since the water running through this gully over long periods of time would have laid down different deposits in successive stages. Evidently, he mixes these soils together--which he calls "modular"--and that makes up the water retaining soil he uses for the core and the basin.
He is going to come Thursday morning to dig a couple of holes to see how deep this material goes, but based on his knowledge of the local area and what he has seen on my property, he is pretty well certain that a water-retaining pond can be made here.
Some test holes were dug. Needless to say, I never cease to be amazed at how much soil can change in such a short distance:
This first hole was started right behind where the core will be:
I had mixed feelings about the results of this first hole. It was not very far before we hit "black shale" as they call it here. However, they maintain that this black shale will actually hold water. There was only a small band of clay:
The second test hold was quite impressive. This was more forward in the first third in from the core. It was quite a bit deeper before the black shale, and had a very large depth of excellent clay:
The third test hole was perhaps the most fascinating. Moving still further up the pond basin, and over to the other side, this hole was filled with eons of deposit that had run down off the adjoining hillside. It went about ten or twelve feet before hitting the black shale, and was composed of both silt and clay:
Backhoe guy waiting for instructions where to dig next:
They nicely filled everything back in and smoothed it out. I could mow over where they had been:
They also staked out with the laser level where the water line would be. I was very pleasantly surprised to see how much wider it was going to be (I had assumed less due to optical illusion).
I have been toying with the idea of leaving these two center trees in the basin bottom, just to build a structure or fort in above the water. My chief concern is longevity and, therefore, stability and safety for the kids a little down the road:
And then they leave:
Next phase hopefully coming soon . . . .