Let me suggest that nothing be done about the dismantling of the dam at Sweet Pond other than to allow beavers to come in and build a new dam.
Beavers are very skillful engineers and have been known to construct very large, expert dams. They also maintain their dams. This would cost the taxpayers nothing. A few lodges would go up in the prime real estate thus created. The wildlife and fish could return!
What about road flooding? Beavers only build a lake to the depth necessary for them to survive over the winter and to maintain the safety of their lodges. Sweet Pond rests low in relation to the road anyway.
What about giardiasis, the parasitic disease which can infect people's small intestine, causing diarrhea and other symptoms? Well, not all beavers carry it - and many other animals, like deer, do. It is never wise to ingest untreated water anywhere, whether beavers reside in a lake or not.
Beaver ponds, interestingly, function largely as water purifiers. I used to live on an Indian Reservation where the sewage treatment system and pools were not maintained for a few years. Raw sewage just poured into the creek. However, when a federal inspector finally appeared, he found that the water tested fine downstream.
Then it was discovered that there were three small beaver ponds between the sewage treatment plant and where he tested the water. The beavers were cleaning the stream - that is, their ponds exposed the water to the oxygen and light necessary to purify the water. This became a joke on the reservation as the old Indian who lived on that property said, “I'd been meaning to go out and shoot those beavers someday, but I just never got around to it!"
Similarly, any beavers who appear to fix the dam and restore the pond ought to be left unmolested to do their work. I used to live in Guilford off of Sweet Pond Road, and came home from work at midnight. One night, I saw something approaching in the road near Sweet Pond. It was a beaver dragging a tree far heavier than itself right down the middle of the road.
I stopped the truck. The beaver seemed quite annoyed as he re-positioned the long tree, front and back, over to the left side so we could both use the road. I stayed still watching it drag the tree past the truck. It didn't even look up at me as it passed.
Let the beavers take care of Sweet Pond!