Pond renovation can be significantly less if the pond is down sized and spoils are spread into shallow weed prone areas. One acre of water is a lot to manage properly, cost and labor wise. Large is not necessarily better especially if the pond is shallow, nutrient rich, and prove to excess plants.
Thank you for that thought because it actually caused me to do something different with my daughters pond during renovation. We actually expanded the pond to one side, but while cleaning out the muck in a portion of the shallow area of the old pond, the light bulb came on upon remembering your post and I decided it was much easier to move new dirt and cover up a portion of the old pond (making the new part deeper than it would have otherwise been) than it was slip sliding around pushing that muck up out of a hole. So while I cleaned part of it out, another part that was close to the water and was much more problematic to clean out we just did a re-design of how the pond would look and covered it up. For X amount of machine time spent, I think we ended up with a better project!
A trackhoe would have been the ultimate answer but don't think there are any plans for one being under the Christmas tree.
