S.T. Since the pond is at the bottom of a hill with soil maybe marginal for packing and the finished size is 25x60, I would look into the price of a commercial pond liner. Just an option to consider. This will provide a water tight pond so you can maintain a full pond. Nothing worst than a leaky pond, esp. during a drought year . Visit
www.coloradolining.com (in the Resource Guide on Opening Page) or [URL=http://www.gseworld.com, [url=http://www.gseworld.com[/URL]]www.gseworld.com[/URL][/url] or
www.yunkerplastics.com. If you are lucky enough to get a spring to feed the pond, no problem. Remember bulldozers by themselves are not very good packing tools; weight is spread out over the tacks. The side walls should have good clay packed tightly several feet thick around the entire basin. YOU DIG A HOLE BUT YOU BUILD A POND! Holes leak. good luck.