855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 168

Extracted Content

WATER EFFICIENCY (WE)

OVERVIEW

LEED v5 integrates water efficiency with new stewardship strategies, redefining water as a valuable and limited resource. The WE category encourages projects to conserve potable to safeguard ecosystems, reduce energy use, and boost resilience on-site and in the wider community.

New construction projects can design highly efficient water systems by combining LEED’s proven efficiency strategies with innovative water stewardship approaches. While global water efficiency has improved, water stress and scarcity remain pressing challenges, with approximately 2.4 billion people living in water-stressed regions as of 2020. [81] Climate change and population growth intensify these issues, underscoring the need for adaptable, forwardthinking resource management plans.

The connections between efficiency and stewardship show up clearly in the whole project water use strategy ( WEc2: Enhanced Water Efficiency ). Rather than isolating individual components, this approach encourages comprehensive site-wide water consumption assessments. Originally piloted in LEED v4.1, this strategy has become a permanent feature in LEED v5.

This stewardship approach aligns with growing market interest in alternative water use, seen in water-limited regions like California. [82] By incorporating alternative water sources, projects can reduce reliance on potable supplies, alleviating the strain on overburdened systems ( WEc2: Enhanced Water Efficiency ).

Decarbonization Water efficiency can significantly reduce energy use and carbon emissions. For example, running a faucet for five minutes uses about as much energy as letting a 60-watt light bulb run for 14 hours. [83] LEED v5 advances decarbonization efforts by reducing the energy use linked to inefficiencies within water treatment, transportation, distribution, and heating ( WEp2: Minimum Water Efficiency, WEc1: Water Metering and Leak Detection ). Additionally, new appliances must

81 Martin. 2023. “Water and Sanitation - United Nations Sustainable Development.” United Nations Sustainable Development. October 19, 2023. https://www.un.org/sustainabledevelopment/water-andsanitation/#:~:text=Investments%20in%20infrastructure%20and%20sanitation%20facilities%3B%20protection%20and,efficiency%2 0is%20one%20key%20to%20reducing%20water%20stress. 82 “Water Reuse Case Study: Los Angeles County, California | US EPA.” 2025a. US EPA. January 31, 2025. https://www.epa.gov/waterreuse/water-reuse-case-study-los-angeles-county-california. 83 “Why Water Efficiency | WaterSense | US EPA.” n.d. https://19january2017snapshot.epa.gov/www3/watersense/our_water/why_water_efficiency.html.

U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 158