Thanks for the response.

The damn under the first pond failed slowly but surely over about 20 years. It just gradually eroded away. You can look at timelined aerial photographs and see the pond gradually shrinking, and then all the sudden in 2009, it just disappears.

The job might sound big, but the 2 ponds are pretty tiny. Pond 1 is probably 1/8 acre and I would guess the combined spillway dig and enlargement of pond 2 would be another 1/8 acre.

That said, if I rent a full-sized excavator, I could probably do a lot more. They're just really, really expensive. 50% more to rent for a week than a mini is to rent for a month.

The damn for pond 1 isn't very big. Probably about 2 feet of depth and 10 feet of length that's washed away. If I dug the pond out about 5 feet, I wouldn't even need to reinforce the damn much at all, even though I know you can't tell that from the picture. The pond filling in has been as much or more of an issue than the damn washing down.

I will need to read up or take suggestions on how to keep the dirt from just filling back in once I dig the spillway back out. Although I'm guessing that's something that will just happen over 20 years of a non-maintained pond.