Thanks all,
plan to do something similar this go round, just bigger and better.
As for the tops in the last 2, that's grape vines and pine straw, make shift shade netting as that pen had lots of northern species in it.That and there were lots of grown trees I just went around when building. Every now any then, I'd have to cut a hole in it and get some straw off to ease the weight, then just sew it back up.
They all loved the shade from it during our south Georgia summers though, so did I, LOL
As for the over flow, this pen didnt just concrete ponds with pvc filler to each, this one had 3 ponds in it, 2 large and one small.
I did have one with a waterfall from a small pond to a larger pond, it recirculated back to the top smaller one, and had a make shift creek between the two for the water to flow between them in.
These are just set up with adjustable pvc water misters in it for refilling or spraying mist in the summer. Summer or winter, they seemed to love to just sit in the mist from them. In the pics it was on a maintaining flow, but can be set to a fine mist which they really loved. In the winter, this made ice cycles off the netting, which they always loved to eat on, made me cold just watching them, but as they day would warm and pieces fell into the water, they'd be on them like it was candy to eat them...
edited to add,
look at the second to the last pic, that pond is on a fine mist spray and look where they are all sitting! Those goldeneyes really loved it, all the divers did .