Here are some pictures of the bowl area of the pond. I said earlier that it would be shaped like a motocross track and after it settles down with some weather it would actually work for one. Except for the fact it will be filled with water.
Descriptions with pictures.
Did I compact the basin? No. Unless we run into sandstone outcrops, coal seams, shale seams, or gravel beds from an ancient stream bed we simply do not have problems with ponds not holding water. Compaction will make them hold tighter, but compacting the bottom would not let me have the underwater structure diversity you see in these pictures. The clay pan soils we have in this area are a blessing for making ponds and a curse for our farming operation. Very little water soaks down, it has to evaporate away (something like a few one hundredths of an inch per hour water percolation in our subsoil). So a wet spring for us is a real problem. And it happens regularly.
Plus by not having to compact allows me to "cheat" on the depth. An explanation is in order. The scraper is the best tool to move the clay from the bowl to the dam. It serves dual purpose by not only moving the dirt but also compacting the dam in the process (with additional compaction only passes). The problem with a scraper is that it takes some distance to "load". Once I get to about a 6' depth in that size pond it gets hard to get a full load on a single pass for two reasons. The clay moisture increases so the tractors tires are on "greasy" footing so not as good for traction. And half the distance is now trying to load up hill, which is much less efficient. By putting these "underwater humps" out in the middle it allows me to use the scraper to move most of the dirt down to about a 6 or 7 foot depth, then as the dozer creates the humps I can create deep pockets with it. Where you see the water in the pictures most of these areas are about 9' deep with one hole at 10'. That is what I meant by cheating. It allows me to get the bulk of the material out with the scraper, then dig some deep holes with a short push of the dozer. The loose clay humps will eventually settle down a foot or so from their current height.
Edit: Warning! This only works with soils/clays that seal themselves well. Most people likely do not want to go without compacting the bowl of their pond because there is a good chance they will end up with a leaking pond. It could even happen to me here if there happens to be a gravel bed just below where I am digging and I do not discover it. So pond builder beware. I am taking a calculated risk that other potential pond owners might not want to take for fear of having a pond that will not hold water. I am not a professional pond building contractor. I'm a retired farmer with too much time on my hands. Do as I say, not as I do! If I screw it up, I'm the one that has to fix it!
If I screw it up, I'm the one that has to fix it!
