A new study finds that light-colored rooftops can help California cities save water by requiring less of it for lawns and gardens.
The recent work from researchers at Lawrence Berkeley National Laboratory, says that the widespread adoption of "cool roofs" could reduce outdoor water consumption by as much as 9 percent.
The study, published in the journal Nature Communications, marks the first body of research to look at the link between water and heat mitigation strategies in urban areas, says co-author Pouya Vahmani, a scientist at Berkeley Lab.
“You might not do cool roofs just to save water, but it’s another previously unrecognized benefit of having cool roofs," Vahmani said in a press release. "And from a water management standpoint, it’s an entirely different way of thinking – to manipulate the local climate in order to manipulate water demand.”
The average temperature of cities with high concentrations of cool roofs can drop by 3 to 4 degrees, which, as the Mercury News reports, is enough to save cities like San Francisco from about 4 percent to more than 7 percent of the water used per person daily for landscaping needs.