Darn Nepen, so sorry about that.
I did fishing line, alligators, fencing, heron statue, none kept the heron away for any length of time. I have videos of the heron circling the pond staring at the gator heads in the water, they moved with the wind. Well the heron decided it was safe and went back to fishing. I had two heads, one at each end of the pond.
The wide weave netting hung about 3 feet over the pond surface finally stopped them. With my pond I just have a bit draping down where the heron could walk up, messing with its natural coiled neck strike. With jw's pond she has that netting plus fencing.
Look into a the wide weave netting that jw and I use, it does not trap anything like frogs small birds, high enough over the pond water that lilies can grow and bloom without being smashed by the net.
@j.w She has a nice thread about it some where here.