Gator,
The drain is not really a drain. It was just there to let the water out as we built it. It has a cap on it now.
I just got a call from my neighbor. We had about 2+ inches of rain yesterday and the water is flowing out of the siphons. I guess that means it's full! WooHoo! Now we have to adjust the vent pipes to fine tune the level.
Pictures soon.