Reuse what you can.
One Bryant Park saves 8 to 10 million gallons of water that another building its size might use each year, according to Winston. That's mainly because it captures all the water that lands on it or seeps into it.
First LEED-Platinum skyscraperA tank in the hollow space below the elevators will harvest 3 million gallons of groundwater each year. Cleaning this "graywater" involves a series of tanks and pipes that treat the water to cool the building and flush the toilets (except the urinals, which use no water). Program the tanks a little differently, and you can even recirculate sewage, or "blackwater" on any site with cellar space.
"This has been something of a science experiment," says Winston. "In looking at future projects, treating blackwater is not necessarily much harder."
NEXT: Cool the floor.
