Years until the Savings Equals the Investment.
(photo credit: JERUSALEM INSTITUTE FOR POLICY RESEARCH)
Atop a 1,000-sq.m. roof of a school building, rainwater runs into gutters at the perimeter. Through the gutters, the water flows into a large reservoir, connected to the school’s toilets by a separate line to avoid cross connections with city water.A pressure switch activates only upon a toilet flush in the school bathroom, causing the water to flow once again and refill the toilet.