The benefits of rainwater harvesting go beyond reducing water costs. Attain LEED credits through the US Green Build Council.


 
 

Below you will find information on how rainwater harvesting can help with LEED v4 Accreditation.

Outdoor Water Use Reduction:

1 to 2 Points:

"Reduce water demand by 50% from the highest demand month (calculated).  First achieved by selecting native plant species and use of irrigation system efficiency.  Additional reductions (beyond 30%) can be used by any combination of efficiency, alternative water sources (rainwater), and smart scheduling technologies (ex: smart irrigation controllers, rain sensors, rotating sprinkler nozzles)."

Indoor Water Use Reduction

Variable Points:

Potable water savings can be earned by using alternative water sources (rainwater):

  • 1-point for 25% reduction
  • 2-points for 30% reduction
  • 3-points for 35% reduction
  • 4-points for 40% reduction
  • 5-points for 45% reduction
  • 6-points for 50% reduction

Cooling Tower Water Use

1 point:

Use a minimum of 20% recycled non-potable water

Water Metering:

  • Irrigation: meter water systems serving at least 80%of the irrigated landscaped area. 

  • Indoor plumbing fixtures and fittings:  Meter water systems serving at least 80% of the indoor fixtures and fittings (described in WE Prerequisite Indoor Water Reduction), either directly or indirectly by deducting all other measured water use from the measured total water consumption of the building and grounds.

  • Reclaimed Water: Meter reclaimed water, regardless of rate.  A reclaimed water system with a makeup water connection must also be metered so that the true reclaimed water component can be determined.

  • Other process water: Meter at least 80% of expected daily water consumption for process end use, such as humidification, dishwashers, clothes washers, pools, and other subsystems using process water. 

Sustainable Site Credits

2 points:

95th Percentile:  Use low-impact development (LID) and green infrastructure to manage onsite runoff from the 95th percentile rainfall events. (Must use daily rainfall data and the methodology in the U.S. Environmental Protection Agency (EPA) Technical Guidance on Implementing the Stormwater Runoff Requirements for Federal Projects under Section 438 of the Energy Independence and Security Act to determine the 95th percentile amount.) 

3 points:

98th Percentile: Use low-impact development (LID) and green infrastructure to manage onsite runoff from the 98th percentile rainfall events.  (Must use daily rainfall data and the methodology in the U.S. Environmental Protection Agency (EPA) Technical Guidance on Implementing the Stormwater Runoff Requirements for Federal Projects under Section 438 of the Energy Independence and Security Act to determine the 95th percentile amount.)

Zero Lot Line Projects only – 85th Percentile: only for projects in urban areas with a minimum density of 1.5 floor area ratio (FAR).  Replicate natural hydrology of the site, manage runoff from the developed site for 85th percentile of rainfall events, using LID and green infrastructure. 
 

Past LEED points are explained below:

Reduce energy demands

Using harvested rainwater for non-potable needs requires less energy than municipally supplied water, which uses large amounts of energy through water treatment and distribution processes.

Promote green technologies and water conservation

Reduce stormwater runoff and non-point source pollution

  • Reduce stormwater fees
  • Reduce detention pond areas
    • Increase usable green space
    • Utilize land more efficiently for buildings
  • Protect sensitive waterways

Reuse water onsite for nonpotable demands such as:

  • landscape irrigation
  • green roof irrigation
  • pool or pond filling
  • vehicle washing
    • cars
    •  fleet vehicles                                  
    • emergency vehicles: fire trucks, police cars, ambulances
    • lawnmowers
    • tractors
  • toilet flushing
  • clothes washing
  • fire suppression
  • cooling towers
  • cleaning

Provide a water supply in areas where groundwater is diminished and/or municipal water supply is not available.

Provide an onsite safe water supply during natural disasters and terrorist attacks.

Allow for irrigation during times of drought, which promotes plant health and reduces the heat island effect and subsequent energy demands around buildings.

Collect water during heavy rains, which cannot be absorbed into ground, and reapply at the appropriate infiltration rate, encouraging plant growth and reducing stormwater runoff.

Recharge groundwater aquifers with collected rainwater.