The big question for this credit is how your team will demonstrate compliance. Though this credit is similar to the LEED 2009 credit that addresses landscape irrigation use, the v4 iteration stipulates different compliance paths depending on the conditions of your building’s systems.
Find out what’s behind options 1, 2, and 3
The first and easiest path is when landscaping does not require irrigation. If not, the credit is yours via Option 1.
If your landscaping does require irrigation there are two separate paths to compliance, depending on whether or not you have irrigation metering installed. (Teams should also know that projects with no landscape area automatically meet Option 1 and earn the credit.)
For Option 2, if your site doesn’t have an irrigation meter, you need to calculate the expected landscape irrigation reduction using the EPA WaterSense Water Budget Tool. Most landscapes that use basic water conservation strategies such as low water vegetation, drip irrigation, and WaterSense controllers are likely to meet the 40% reduction threshold. The catch is that the project must also install an irrigation meter before the performance period ends in order to earn the credit.
If your site already has an irrigation meter you must pursue Option 3, and it will likely be much harder to demonstrate compliance with the credit threshold. In this case your performance is calculated based on a straight reduction from your historic metered water usage. If your team has made efficiency improvements to the irrigation system recently, this credit may be good to pursue.
What’s New in LEED v4
- The U.S. EPA WaterSense Water Budget Tool is now a referenced calculation tool.
- The performance thresholds and points available have changed compared to the WEc3: Water Efficient Landscaping credit from LEED 2009.
Readiness Review Questions
- Can plantings thrive without a permanent irrigation system (Option 1)?
- If your project doesn’t currently have irrigation metering in place, it is feasible to install (Option 2)?
- If irrigation systems are already submetered, are records of potable water use from previous years available (Option 3)?
- Do you have landscaping plans that show species composition and areas?
- What opportunities exist to incorporate native or adaptive landscaping onto the project site?
- What opportunities exist to optimize or upgrade the irrigation system?
- Are there local, regional, or state programs that assess irrigation performance in your area?
- Could graywater or captured rainwater be used to meet irrigation needs in whole or in part?