Function stacking - rainwater harvesting, patio, and fun for kids

I stumbled across a design yesterday and thought it was off-the-map clever.

What if you need a new patio?  ...And what if that patio's surface area could harvest rainwater in addition to your roof?
In fact, why not use the area underneath for a 5000 gallon rainwater cistern to store that water?
Finally, for extra credit, why not make the whole thing into a splash pad for the kids to play in?

The following design does just that!


Okay.  Project 907 officially added to my "things I want to do right now" list! :)

That is a very clever idea.
I might use a circular stock tropugh as the basin, thanks.