Randy, I did take a guess and I invited a dozer contractor to start clearing the land for the pond. Fortunately, while he was waiting for me, a rancher showed up and told us about the 3 yr floods in that seasonal creek. Talking about change of plans on the spot! You are so right about talking to the people who lived on the land their whole life. I have a neighbor out there, who knows as much about ponds and fish as anyone on PondBoss - with the exception of few scientific types. I need to show up with a sixpack one day and pick his brain some more.
I have AutoCAD R14 on my work laptop. That is a good idea. I can download the topo maps, or draw the watershed based on the topo maps and have it calculate the area. Than use the runoff calculator from Eastland.
E, you are welcome to come by. I don't live out there, but I am always looking for an excuse to go. Let me know next time you are heading that way.
lloydian, thanks for the link.