A 7,500-gallon concrete cistern collects rain runoff and provides over half of their water for both potable and nonpotable uses. A diversion valve ensures that the first raindrops wipe the roof clean of debris. Then the water runs through copper gutters into the cistern, where three filters treat it. The filtered water is pumped into the house through copper pipes via a solar-powered jet pump.
The house features other water-saving devices, too, such as low-flow showerheads and an on-demand water recirculation system.