This is great since we don't have any outdoor hose hookups! How to Build a Rain Barrel. A dual barrel system that uses atmospheric pressure to equalize the water volume in both rain barrels. Use the water from your rain barrels to water your plants.
The owners of this pen say that they really like the lobed-shape of their pool because the ducks can swim in their own areas. Based on their other photos, I don' think they have a drain, so they have to lift the whole thing out when they need to clean it.