3 years vs 30 years. And you usually regulate the river around the dam so it can't meander, beaver dams make the river meander around them. So after 30 years yo

3 years vs 30 years. And you usually regulate the river around the dam so it can't meander, beaver dams make the river meander around them. So after 30 years you maybe return to status quo with a small, abandoned human dam. In that time you would have 10 different riverbed changes with beavers and all that area is now marsh.