The same thing happened in the Logan River after the 1974 floods.
My father in law used to catch some terrific flatties in the river in those days from some favourite holes and every time that I went-a-courtin' his daughter who obviously subsequently became my wife, I had to view the latest catch
, and I can attest that they were fabulous fish.
Then the 1974 flood came, the holes changed and the bonanza of big flatties on every fishing trip was no more.
That was before the days of sounders, of course.