From the look of the drawing and the four foot intervals on the contour lines, it looks like close to an 8ft drop. That means you will have to build a dam 8 feet high for the water to be level, then another couple feet for freeboard. A dam this tall will have to be about 8 feet wide at the top and with 3:1 slopes, it will have to be almost sixty feet wide at the base.
I'm not sure how long you plan to make this dam, or levy, but you'll be moving a massive amount of dirt. How are you going to do this?
You said that it would be too expensive to dam up the creek. How did you come to that conclusion? I'm of the opinion that the less dirt that you have to move, the less money that you will have to spend.
Eddie
