Am meeting with contractors over the next few weeks. The more I look at the sight the more confused I become. The back end of the lake will need some excavating to keep from being too shallow. The length of the lake is 900' with about 1' of fall per 100'. That means if the min depth is 2' I will need to excavate 2' from a 1 acre area and 1' from a 1 acre area. Is 2' too shallow over 2 acres of the back end? That means 1,613 cy per 1 acre/ft for a total of about 5000 cubic yards at the back end. This will be 7 acres total lake with a max depth of 9' in front of dam at grade. I have been accumulating some structure to put in the lake. Am planning on digging holes with my auger and cementing cedar trees vertically in the lake. Have also spotted a large pile of large tires and pallets for free.

Dam volume is 5,200 cy according to NRCS. I calculated 6,000. Core trench is 1,700 cy by my calcs.

I have some serious money set aside and believe it will be necessary.

Am planning on a 12" primary spillway made from smooth bore pipe with 2 antiseep collars made from 1/4" plate. I will control level of lake on downstream side of dam based on height of leg. Will put a tee on downstream leg allowing for potential to drain lake. Have a 8" gate valve in possession. Am debating placing valve 3' from top to lower lake level 3' in the summer to allow for planting of japanese millet. After millet heads and duck season is close closing the valve and flooding the millet.

I am open minded and welcome advice.