The rain barrels are connected to the gutters on the barn and are working great, maybe a little too great. About one inch of rain fills all four barrels. We are looking into getting a larger barrel, about 250 gallons to act as a reservoir.
The hose is the overflow line. The barrel in the foreground is a little lower than the others and has another hose down low which goes into the garden so I can use the rain water on the veggies. All in all I'm pretty happy with the set up.