One of the best birding spots in my area is Bundsø.
It was dammed up in 1590, and completely drained to be turned into farmland in 1850.
In 1980, the drinking water reserves on our island were so damaged, that it was decided to flood the lake again.
This being Denmark, progress was slower than a herd of turtles, but finally, in 2015 the drainpump was shut down.
Aage V. Jensen Charity Foundation bought it in 2019, so hopefully, it will stay safe and free.