My parents have 100+ acres of bush in central Alberta. When they bought the property it was logged out and mostly in a bad abused state and mostly dry. Over a few years, beavers moved in and transformed a formerly semi-marshy spot into a full pond. And then another. And another.

Eventually though, without a lot of predators around (there's some skittish bears, coyotes, that's it) they begin to overpopulate. And any efforts to keep the water level at a certain point starts to get tricky. In order to keep access to some parts of the property my dad ended up having to put in some sneaky culverts with various tricks to stop them from plugging them. (I forget, but he eventually figured out a beaverproof trick).

Even then, every few years the need to "remove" some of the beavers, because they just get to be too many, the run out of poplars near their lodge and start to cause more problems for downstream neighbours.

They've done amazing things for the property. But when my parents pass it's going to be hard to maintain this property with the beavers actively trying to transform it constantly.