855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 136

Extracted Content

Eligible end-uses

• Irrigation . Use rainwater to water gardens, lawns, and agricultural fields, reducing the demand on municipal water supplies.

• Flush fixtures . Conserve potable water for drinking and cooking when used in toilets and urinals.

• Makeup water systems . Use rainwater can serve as makeup water for cooling towers and boilers, which require large volumes of water for operation.

• Process water demand . Industries can use harvested rainwater for processes that do not require potable water, such as washing, cooling, and other operational needs.

Additional considerations Project teams considering rainwater reuse may also earn points under the WE Credit Category. Consider using rainwater for toilet flushing or irrigation to earn

additional points for WEc2: Enhanced Water Efficiency to pursue these

additional points.

Option 2. Natural Land Cover Conditions

Option 2 requires that the proposed design retain the increase in runoff compared to the natural land hydrology of the project site. Under this option, projects must maintain runoff on-site and design the site to mimic natural hydrology. This strategy provides absorption and filtration, supporting diverse ecosystems by maintaining a balance of water levels in wetlands, rivers, and lakes. Natural land covers, such as forests and grasslands, often allow more water to infiltrate the ground, recharging groundwater supplies and reducing the volume and speed of runoff.

Natural land hydrology Natural land hydrology reflects the natural land cover function of water occurrence, distribution, movement, and balance. Teams must determine how quickly water can seep into the existing conditions or soil, which influences groundwater recharge and surface runoff. Site features like topography, soil, and surface water bodies, along with pre-design connections to nearby ecosystems, help maintain natural land hydrology.

Rainfall event Document historical rainfall data for the project boundary; however, unlike Option 1, specific percentile events are not required for this option. Project teams must use a full range of hydrologic rainfall events over a 10-year period or develop an average representative rainfall year, then use the following process to determine the average runoff volume under natural land cover conditions:

U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 126