CC are cavity nesters. So, without having a barrel in there for them to spawn in, or a steep bank that is relatively stable so they can hollow out a cavity, they most likely won't reproduce in the pond. CC are cheap to stock, if you can stock 12" fish in the Spring and you feed them, they can be 18" by the Fall.
With the pond aerated with a windmill, watch so that the fish population doesn't get too high. Windmills tend to stop aerating just when the pond needs it the most.
