You didn't get what I said and I am not surprised. Both residental and rain water needs to be filtered, cleaned and disinfected. Not sure why you missed out chlorination of rain water.. you really don't want all the bacteria lurking into your toilet and props.

Commercial scale rain water you say? Roof or standalone collectors, contact tanks, pressure tanks, pumps. All made from plastic and coal > steel production. Excavators, truck transport and local waste. Very environmental friendly, right?

Be sure that doing this once per town in large scale is much less impactful than doing this per house in smaller scale.

Huge difference is town projects use natural reservoirs of water (where possible ofc) instead of huge plastic "bottles" burried in dirt everywhere around.

I admit transportation is a thing. It cost some energy. But local water circulation cost it too! Water needs to be pumped from a source to that toilet. Shorter distance means less energy ofc, but for a less people!

I could go on.. could talk about homemade filtrations, leaks, hobbysits accidents etc. etc. So.. sum all it up please!