What is water efficiency?
According to the EPA, “water efficiency is the smart use of our water resources through water-saving technologies and simple steps we can all take around the house. Using water efficiently will help ensure reliable water supplies today and for future generations.”
Why is this important for buildings?
The U.S. Geological Survey estimates that the United States uses more than 400 billion gallons of water per day. The operation of buildings, including landscaping, accounts for approximately 47 billion gallons per day—12% of total water use.
As residential, commercial, industrial, and other development expands, so does the use of the limited potable water supply, water that is suitable for drinking. Most buildings rely on municipal sources of potable water to meet their needs, from flushing toilets to washing dishes and landscape irrigation. High demand strains supplies and under extreme conditions necessitates water rationing.
Furthermore, large amounts of wastewater can overwhelm treatment facilities, and the untreated overflow can contaminate rivers, lakes, and the water table with bacteria, nitrogen, toxic metals, and other pollutants. To avoid this damage to the ecosystem, additional municipal supply and treatment facilities must be built, at public cost. Water pumping and treatment, both to and away from the project, also require energy, whose production generates additional greenhouse gas emissions.
What are strategies that increase water efficiency?
Green building encourages innovative water-saving strategies that help projects use water wisely. Project teams can follow an integrated process to begin assessing existing water resources, opportunities for reducing water demand, and alternative water supplies. Effective strategies include:
Install efficient plumbing fixtures.
Use non-potable water.
Choose locally adapted plants.
Select efficient irrigation technologies.