Water consumption is one of the greatest threats society has on its natural resources. Everyday, roughly 340 billion gallons of fresh water are withdrawn from rivers, streams, and reservoirs, and 65 percent of the water consumed is discharged back into the water supplies after use. Needless to say, we must focus on water efficiency throughout the world and definitely in buildings.
LEED addresses water efficiency in three credits worth five total points. The overall intent of this category is to limit or hopefully eliminate the use of unnecessary potable water, decrease the demand of wastewater and potable water, and to maximize water efficiency within the building. Points can be earned in this category by water efficient landscaping – which we hope you can achieve by completely eliminating potable water use. Architects can design systems that capture rainwater, recycled wastewater and gray water to hydrate your landscape vegetation. Also, captured wastewater may be treated and infiltrated for on-site use. A vital way to earn points is reducing the amount of water used by at least 20 percent and, for more points, by 30 percent. Water reduction can easily be obtained by installing high-efficiency fixtures, occupant sensors, and use of storm water and gray water.
A water efficient building is responsible, and preserving your community’s municipal water resources and cutting down on water bills is the logical way to build. For example, installing one waterless urinal can save approximately 40,000 gallons of water per year. Imagine if everyone considered water efficiency when building. Again, the details and specific requirements for obtaining points in this category can be found by visiting the USGBC and referring to the USGBC Reference Guide.