*** UPDATE ***
I had another great phone conversation with my contractor the other night. One thing for sure, when I want to talk, he calls me back within 24 hours and spends all the time I need (sometimes I need alot ) Anyway, after we discussed a buncha plans for this year's attack, I told him that I wanted to address his plans for the dam construction once more. I hit him with all my concerns...we have jousted like this before and he is receptive. He assured me that his plan to finish both ends of the core will ultimately wind up being similar to running the entire core at once. As TN HB said, in order to get down into the sides, you gotta ramp in, ultimately cutting back into the center area to do so. We discussed his rolling back the TS with the clay he dug out. Response; suitable method of processing excellent clay subsoil. I asked why he even cut that little section of the core. Response; the bottom/center portion is going to be left as complete, but it allowed him to glimpse at a wide swath of what is down there. I told him I was concerned for use of the D6 to compact. We discussed the lack of compaction of a dozer; he said his D6 weighs 46K and thought he remembers the number "70 psi"...couldn't swear by it without looking. He quickly redirected me; they will use his E-mover to place and compact the core soil in thin layers. He noted that he thinks he is going to bring in a 2nd E-mover due to the amount of soil to move. Knowing full well that I was focused and intent on the dam, he said "I'll tell ya the same thing I have told all my pond clients. Providing there is good clay in this site, we are going to take all the very best material and it is all going to be packed into the core and the upstream side of the dam...period. If it's not here, you will have to bring it in. Best stuff up front...lesser soils go behind". He also added "now, make no mistake, there is going to be soil that gets pushed into place with the dozer on the dam...that's just the way it is during construction, but where is needs proper compaction on the dam, it will be thin layers and run over by the E-movers". I told him that I wanted to see a 1:1 on the edges of the core. He did not object and readily admitted that this is, indeed, standard practice. He said that he didn't normally make an effort to cut his cores back that much, but will be happy to do so for me.
My project will be a short but substantial dam mass. It will be 15 feet high, 20 ft wide roadbed, about 300 ft wide across a valley. The back side is .7 acres and the valley will be filled with pond waste soil. I figure the slope on the back side at about 12:1.
Lastly, my NRCS agent went out and GPS'd the perimeter of the proposed pond, my new driveway, and a couple of property corners. He was able to drop it onto an aerial photo for my latest motivation