Portola Valley Green Building Ordinance
Requirement for New, Single-Family Residential Projects: Reduction of Potable Water Use on Turf.
For all projects with landscapes that include the use of turf, install rainwater catchment system. Irrigation needs of turf should be calculated using the Applied Water for Turf Calculator (tool included below). All rainwater catchment systems must be installed in compliance with Chapter 17 of the California Plumbing Code.
• Rainwater Catchment System Size. The rainwater catchment system size shall be determined by using the “Applied Water for Turf Calculator.” The rainwater catchment system will need to be sized in order to satisfy 50 percent of the estimated annual water demands for the first 500 square feet of turf installed on the project. The rainwater catchment system will need to be sized in order to satisfy 100 percent of the estimated annual water demands for installed turf that is greater than 500 square feet.
• Alternative. A fully installed graywater system connected to an irrigation system that can satisfy all of the annual water demands of turf as identified in the Applied Water for Turf Calculator can be used as an alternative to installing a rainwater catchment system.
* Please print and include the completed Applied Water for Irrigated Turf Calculator with your application submittal (using the "Print" link above).