S.7 Landscape Water Efficiency

Intent
Limit, or eliminate demand for municipal potable water or harvested groundwater (well water) used for maintaining plants and lawn areas.

New Buildings Path: For all sites
Major Renovations Path: For Area of site disturbance > 3,000 s.f. OR Area of imperviousness (footprint of building plus site impervious area) renovated > 2000 s.f.

Required Performance Criteria

1. Design and maintain landscape so that after a 2 year establishment period, the landscape uses 50% less municipal potable water or harvested ground water for irrigation than a base case landscape design. (Exception: annuals are exempt.) Any amount of site-harvested rainwater, storm water, or gray or waste water treated on site to tertiary standards may be used. The criteria may be met by any combination of: selection of native or low water use plants, use of alternatively sourced irrigation water as described, use of high efficiency irrigation systems, or other strategies. In order to verify compliance with this guideline during operation of the building it is necessary to sub-meter irrigation separately from indoor water consumption.

Recommended Performance Criteria

2. Design and maintain landscape so that after 1-2 year establishment period, the landscape uses no (100% less) municipal potable water or harvested ground water than a base case landscape design. (Exception: annuals are exempt.) Any amount of site- harvested rainwater, storm water, or gray or waste water treated on site to tertiary standards may be used. The criteria may be met by any combination of: selection of native or low water use plants, use of alternatively sourced irrigation water as described, use of high efficiency irrigation systems, no irrigation systems, or other strategies.

Compliance Tools and Resources

• Typical Irrigation Water Use: See Appendix S-7 Irrigation Water Consumption
• Custom calculation or manufacturer worksheets such as Rainbird or Toro Irrigation Worksheet