Strategies Used The building incorporates many of the water saving strategies previously discussed, supporting an unprecedented green project.Indoor Reservoir Five tanks that were constructed in the building's core can hold up to 330,000 gallons of water.Rainwater is collected and stored on the roofs and at points throughout the 52 floors.The reclaimed water is filtered and disinfected and then used for flushing toilets, cooling tower makeup or steam production.Rooftop Rainwater Ninety-five percent of the storm rainwater water collected onsite is reused.The water is used for flushing and uses a gravity-based system.