Duck pondering

Back when we put in swales, we wondered how much water the back-most one would hold. Water comes down from the hill above us, sometimes in huge quantities but often at least a trickle. It seems to stay pretty full from about November through June, though it often dries out over the summer. Right now it has water and a thin layer of ice.

Future duck pond?

Last year, Josh modified it a bit, added a bit of a dam near where most of the water comes in to create a deeper ponder area and then a shallower spillway.

Pond area into swale

I'm wondering whether I can make that pond a bit more permanent, holding water more tightly, and whether I can find a way to keep the water from freezing, maybe with a simple windmill. I'm not sure that holding water better is actually going to be enough to keep it from drying out in summer, but maybe. I'm also not sure that I can come up with a non-electric way of keeping some water open in winter - but again, maybe.

If that all works, then I have to figure out what kind of home to build on it for the ducks. (Ducks don't absolutely need open water, but I'd like them to have some...)