Boomer,
If I were building a one acre pond tomorrow, I'd call one of my friends to do it. I'd get someone in the excavating business. Even though I've got a lot of seat hours, I believe my friends could do such a pond in a fraction of the time that I could, and I'd have a better product.
If they are in the business, they will have more modern "toys" than you will ever hope to own. A good local excavator will be able to visualize gradients you'll never see. They will know the local soil. They will come in with a lot more equipment than just a dozer.
The second possibility is renting. But, for a one-acre pond, you probably need more than just a dozer. You really should have a way to move the dirt a long ways (trucks, loaders, etc.), and you should have a way to compact the mud (sheepsfoot).
I'm sure Otto can tell us a lot more. But for a one-acre excavation, I wouldn't want something smaller than a Cat D6-equivalent, just to push dirt.
Good luck,
Ken
