My construction techniques are fairly simple. I use a tiller to pulverize the soil to be excavated. The loose soil is scooped out and deposited to form a dam on the downhill side of the proposed pool. The soil is built up in successive layers of an inch or less of soil. Each layer of loose soil is fully compacted before the next layer is added. The idea is to end up with a tightly compacted barrier to keep water from leaking out of the filled pool.
The soil on this site has no shortage of rocks. Plowing activities that occurred several decades ago moved rocks to a higher position in the soil profile. On this location, the plows must have been dragging very near the top of the bedrock layer. During my excavation, I have encountered a couple of bedrock areas that were pulverized by the ancient meteor impact to a condition nearing small gravel. This makes me wonder if the site will be capable of maintaining water for the period necessary for a batch of toads to be successfully raised.
I decided to finish this year with a pool that is smaller than planned. I’ll see how well it holds water next spring and then decide if it is worth the effort to enlarge the pool area. If it doesn’t hold water, I’ll then consider the option of installing a pond liner.
On November 30, a half inch rain put the first bit of water into the pool.
Another half inch of rain a week later brought the pool to within a few inches of being full. There are three seasonal springs that feed into this area through the winter and spring. With luck, they will produce enough water to offset any leakage in the pool.
On December 17, a 2.5 inch rain filled the pool. Now it’s just a matter of waiting to see what happens.
Toad pool 1, about a quarter the size of the new addition, has proven able to maintain water long enough to raise a crop of spring breeding amphibians. Unfortunately, the first pool is now four years old and I’m still waiting for the toads to discover this gem of a breeding area.