Water Efficiency Impacts

Water use in buildings represents the vast majority of the world's consumption of potable water. In the U.S., which has among the world's highest access to treated drinking water, only 10% of all fresh water is treated for human use. More than 80% of potable water flows through buildings, thus protecting this vital resource depends on improving the ways in which water is used in buildings.

LEED addresses the need for efficient and reduced water use in buildings foremost through conservation. Plumbing systems, cooling towers and landscaping are the main areas where green design can effectively minimize a building's demand for treated water. Devices and practices as simple and cost-friendly as better plumbing fixtures and appliances or time-use irrigation schedules go a long way in preventing "soaked" buildings. Since the inception of LEED, more than half of New Construction and Core & Shell projects have delivered at least a 30% water reduction, with 20% savings from Existing Buildings Operations & Maintenance. Almost 90% of NC and CS projects have achieved 50% reduction in water use for landscaping.

However, saving water requires more than merely reducing the consumption of treated water. On-site treatment strategies promoted by LEED aim to limit building-generated wastewater. Though it is presently unfeasible to expect all future projects to adopt graywater recycling systems, LEED buildings have already made impressive strides in reducing the production of wastewater. To date, one out of five Certified New Construction projects features innovative water technologies such as stormwater or graywater collection and re-use systems.