with the topography up there not being good for dams, you'll have to have alot of dirt moved. 1-3 bucks per yard are probably good guesses. Check with atleast 3 excavators. Should be more than 12 feet deep and 15 if not aerated. You may be better off looking for a property there with some water on it. would be an excellent investment. What area are you thinking about?
Robert B