LEED Credits for Water Efficiency (WE)
WE Credit 1.1: Water Efficient Landscaping (Reduce by 50%)
WE Credit 1.2: Water Efficient Landscaping (No Potable Water Use or No Irrigation)
Intent: Limit or eliminate (50%) or eliminate (100%) the use of potable water, or other natural surface or subsurface water resources available on or near the project site, for landscape irrigation.
Requirements for Credit 1.1: Reduce potable water consumption for irrigation by 50%from a calculated mid-summer baseline case. Reductions shall be attributed to any combination of the following items: plant species factor, irrigation efficiency, use of captured rainwater, use of recycled wastewater, use of water treated and conveyed by a public agency specifically for nonpotable uses.
Requirements for Credit 1.2: Achieve WE Credit 1.1 AND use only captured rainwater, recycled wastewater, recycled greywater, or water treated and conveyed by a public agency specifically for nonpotable uses for irrigation OR install landscaping that does not require permanent irrigation systems.
WE Credit 2: Innovative Wastewater Technologies
Intent: Reduce generation of wastewater and potable water demand, while increasing the local aquifer recharge.
Requirements:
Option-1: Reduce potable water use for building sewage conveyance by 50%through the use of water-conserving fixtures (water closets, urinals) or non-potable water (captured rainwater, recycled greywater, and onsite or municipally treated wastewater).
Option-2: Treat 50% of wastewater onsite to tertiary standards. Treated water must be infiltrated or used onsite.
WE Credit 3.1: Water Use Reduction (20% Reduction)
WE Credit 3.2: Water Use Reduction (30% Reduction)
Intent: Maximize water efficiency within buildings to reduce the burden on municipal water supply and wastewater systems.
Requirements: Employ strategies that, in aggregate, use 20% (Credit 3.1) or 30% (Credit 3.2) less water than the water use baseline calculated for the building (not including irrigation) after meeting the Energy Policy Act of 1992 fixture performance requirements. Calculations are based on estimated occupant usage and shall include only the following fixtures (as applicable to the building): water closets, urinals, lavatory faucets, showers and kitchen sinks.
LEED Category: Sustainable Sites (SS)
SS Credit 6.1 Stormwater Design: Quantity Control
Intent: Limit disruption of natural water hydrology by reducing impervious cover, increasing onsite infiltration, reducing or eliminating pollution from stormwater runoff, and eliminating contaminants.
Requirements: See LEED for New Construction Version 2.2, page 21.
SS Credit 6.2 Stormwater Design: Quality Control
Intent: Limit disruption and pollution of natural water flows by managing stormwater runoff.
Requirements: See LEED for New Construction Version 2.2, page 22.
Source: U.S. Green Building Council, November, 2007