Thanks for the suggestions. I am going to get some line and stakes and put up the anti wading fence.
I don't know what the heron's appreciable impact on the pond is but the impression on me is one of watching a poacher steal what I built with my hard work.
Yesterday, I spoke to a farmer who works the property next to mine and he told me that one of the ponds there had an alligator in it. Maybe the heron can go fish over there.
