We have had our gray water collection in place for several weeks now. This week end Melody had a crowd for two days and Elaine and I were there the same time. We drain the tank each week before we leave. This week it took a full 45 min.to pump the water out as I hand watered trees. I completed the piping from our side of the rain gutters to the tank this week end also. If it looks exposed and unfinished it is. I will not be covering and gluing it together until we see how it works. All downspouts are currently connected together and going to the tank in a 4 inch pipe. We need to be up there during a big rain storm to see if one pipe can handle the flow or if we will have to split the system. We are also experimenting with different additives for odor control.
With our limited experience so far it seems reasonable to hope that were we to start the season with a full tank of snow melt the gray water/rainwater collection might supply most or all of our outside watering needs.
It is rather satisfying to be reusing water in this way.