Pond Boss Forums INTRO Questions & Observations Value of a Test Hole?

Glad you popped this up, PI.

IME test holes are dug to determine what soils are actually located at the dam location (as opposed to interpolating this from soil maps based on very large area samples), and perhaps over the rest of the pond. While I am used to several small holes, your one big one would seem to serve the same purpose (with the added encouraging bonus of a visible pool of water).

One thing I would want to know if I was in your shoes is the makeup of the rock 4 feet down. Does it seem to be solid, nonporous, and unfractured? Those would be good indications. Is it porous sandstone, easily dissolvable limestone, or all full of cracks? Those would be bad; in the presence of such problems I'd want to keep my pond water away from the rock with extreme prejudice by compacting some of that clay on top over it really well. Based on experiences posted here - I'd want 2 feet of clay compacted over "bad" rock.

There are undoubtedly many different bedrocks in the Great State of Texas. Perhaps one of the TX geology types can help identify what rock you have to contend with.