In our March 2008 Elements issue, I lamented the sad state of water efficiency standards in the USGB’s LEED certification program. In an editorial entitled “Green Fever Blues”, I discussed how the current LEED point system marginalized water efficiency. While other categories—from energy to design—accounted for 10 or more points, water efficiency, with a mere five points, was at the bottom of the list.
At the time, I stated that water efficiency must “stand shoulder-to-shoulder with energy efficiency in the national dialogue.” I suggested that the USGBC must acknowledge the complex relationship between water and energy, and incorporate that understanding into its rating system.
“While all water conservation efforts should be applauded, it’s not enough to throw in a couple of low-flow toilets and call it a day. What we need is a broader effort, emphasizing the ying and yang of the water/energy relationship.”
I’m happy to report that change has come to LEED. In April, USGB announced it had updated the LEED ratings system to v2009 for new construction and major renovation. Among the many changes is an updated scoring system for water efficiency and conservation.
Some highlights:
Total water efficiency points have increased to 10.
• The Water Efficiency category has been expanded to include water use reduction, efficient landscape irrigation, innovative wastewater technologies, and water use reduction.
• The points available for indoor water efficiency have increased from three points to 12.
• The Indoor Water Efficiency credit now includes a prerequisite mandating that all LEED projects hit a 20% water savings mark (as compared to a standard baseline).
• Water use reductions are now calculated based on the implementation of “ strategies that in aggregate use 20% less water than the water use baseline calculated for the building (not including irrigation).”
• Points can be earned by reducing the use of potable water irrigation by 50% from a calculated midsummer baseline case.
• Irrigation use reductions “must be attributed to any combination of the following items: plant species, density and microclimate 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
The new water efficiency standards are quite detailed, and I encourage you to give them a look, and let us know what you think about these changes.