We are a campus project pursuing LEED v4 O+M certification. Our campus has a limited number of existing irrigation meters, and we are not able to meet the requirement to meter all outdoor water use on a per building basis. One building on campus would require additional funds in order to install a meter for a small patch of grass receiving potable water irrigation; another building receives several sources of potable water for irrigation and installing a meter for each source is cost-prohibitive . Is it possible for us to achieve LEED v4 WE prerequisite Building-Level Water Metering using the campus irrigation data?
The project is requesting clarification as to how to document compliance with LEED v4 WE prerequisite Building-Level Water Metering, given that the project has a limited number of existing irrigation meters, and metering all outdoor water use on a per building basis may be cost prohibitive.
For compliance with LEED v4 WE prerequisite Building Level Water Metering, the campus projects with existing irrigation meter(s) measuring total campus irrigation water use may submit an engineering calculation that accurately reflects the water consumption of the landscaped area for each building within the project boundary, or prorate irrigation data for each building within the project boundary from the campus meter.
If the project chooses to prorate irrigation data from the campus meter in lieu of installing irrigation meter(s) to track landscape water consumption for each building within the project boundary for WE prerequisite Building Level Water Metering, irrigation water systems are excluded from the list of water subsystems eligible for each project pursuing WE credit Water Metering.
Campus projects that use prorated irrigation data for the purposes of compliance with WE prerequisite Building Level Water Metering must; 1) submit campus level metering data and 2) provide engineering calculations for prorating the irrigation within the project boundary. Projects using this compliance path must use Option 2 if pursuing WE credit Outdoor Water Use Reduction.