Years ago we dug a shallow bog next to the regular pond.
We learned a lot from the whole experience and that was
valuable in and of itself.
But the plants grew so fast and filled in the bog so much that
finally there was little water in it and I didn't want any tadpoles
to end up in peril.
Ending the frog bog has taken longer than we'd have liked.
First DH poked holes in the liner to drain it. Then he started
in with his flame thrower (and set the lawn on fire but that is
another story).
He recently took advantage of having a small grader that was
leveling an area below our new deck to attach one end of the
liner to it and drag it free. Then the dirt from the graded area
went into the old bog and it will be ready for seeding whenever
DH gets around to that.

Bubbler in the pond, ready for winter, had a skim of ice the other
morning.

k :-)