Thanks for replies. Robinson, I have a huge hill of topsoil (which has a lot of clay in it) behind the dam so I don't think it will wash away. I guess I still need to wait.
Dribble creek, the layer is fossilized shells about dime sized with small gravel and clay mixed with it. I don't understand the second question.
Mercury, there is a small pond above it that I could pump from but is so low that I dug a hole to pump the precious liquid into so the heifers can drink without getting stuck. I guess $75,000 worth of heifers are more important than my pond. Another week or so the pond will be dry.