CS-v5 WEp2: Minimum Water Efficiency Required

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© Copyright U.S. Green Building Council, Inc. All rights reserved.

Intent

To reduce potable water consumption and the associated energy consumption and carbon emissions required to treat and distribute water, and to preserve potable water resources through an efficiency-first approach.

Requirements

Meet all minimum water efficiency requirements outlined below.

Minimum Fixture and Fittings Efficiency
Meet the following minimum water efficiency requirements for fixtures and fittings.

Projects located where standard supply pressure is different than the LEED baseline supply pressure may calculate the water consumption of flow fixtures and fittings at the local standard supply pressure.

OPTION 1. PRESCRIPTIVE PATH — MAXIMUM FLUSH AND FLOW RATES
For all new and existing fixtures and fittings within the project boundary, do not exceed the maximum flush and flow rates listed in Table 1.

Table 1. Maximum Installed Flush or Flow Rates for Prescriptive Path

_{NOTE: gpf = gallons per flush; gpm = gallons per minute; lpf = liters per flush; lpm = liters per minute.}

_{^aThe WaterSense label is available for this fixture type. WaterSense-labeled fixtures are recommended for projects located in the U.S. and Canada.}

_{^bFor dual-flush toilets, the full-flush volume shall be equal to or fewer than 1.28 gpf/4.8 lpf; A weighted average cannot be used.}

OR

OPTION 2. PERFORMANCE PATH — CALCULATED REDUCTION
For all new and existing fixtures and fittings within the project boundary, reduce aggregate water consumption by 20% from the baseline listed in Table 2.

Table 2. Baseline water consumption of fixtures and fittings

_{NOTE: gpf = gallons per flush; gpm = gallons per minute; psi = pounds per square inch; lpf = liters per flush; lpm = liters per minute; kPa = kilopascals.}

_{^aThe WaterSense label is available for this fixture type. WaterSense-labeled fixtures are recommended for projects located in the U.S. and Canada.}

_{^bFor duel-flush toilets, the full-flush volume shall be equal to or fewer than 1.28 gpf/4.8 lpf; A weighted average cannot be used.}

AND

Minimum Equipment Water Efficiency
Newly installed appliances, equipment, and processes within the project boundary must meet the requirements listed in Tables 3 and 4. Existing appliances and equipment can be excluded.

Table 3. Standards for Appliances

_{NOTE: gpm = gallons per minute; lpm = liters per minute.}

Table 4. Standards for Processes

AND

Minimum Outdoor Water Efficiency
OPTION 1. NO IRRIGATION
Show that the landscape does not require a permanent irrigation system beyond a maximum two-year establishment period.

OR

OPTION 2. EFFICIENT IRRIGATION
Reduce the project’s irrigation water requirement by at least 30% from the calculated baseline for the site’s annual theoretical irrigation requirement (TIR). Reductions must be achieved through plant species selection and irrigation system efficiency, as calculated by the TIR methodology outlined by the U.S. Environmental Protection Agency.