Rollback to Island living, everything is precious and a bit expensive including fresh water. Rain barrels will make a concerted comeback and higher volume catchments will be more commonly installed under decks and patios. These were common for gardening in homes in SoCal and central calif before water diversion programs brought copious amounts to the tap. They won't support the average person's acre+ of inedible grass but they should cover most plants, assuming that roofing material doesn't add toxics. Plumbing for recycled gray water too. I try to encourage my son to journeyman as a plumber, such skills will remain in high demand in the 21st century assuming you don't tweet and twitter and make a fortune replacing the postage stamp (along with the postal workers).