The Loma Prietan - July/August 2010

What the State Has Done

New Ordinances Mandate Landscape Water Efficiency

by Catherine Elvert

Water is in short supply generally in California. Since outdoor irrigation accounts for roughly half the water consumed by a typical household, the state of California is working to reduce landscape water use.

Last September the Department of Water Resources (DWR) adopted the updated Model Water Efficient Landscape Ordinance required by AB 1881, passed in 2006. AB 1881 requires cities and counties to have adopted DWR's Model Ordinance or one "at least as effective" in reducing landscape water usage by the start of this year.

The Model Ordinance applies to most commercial new and rehabilitated landscapes over 2,500 square feet and to homeowner-installed single-family new construction over 5,000 square feet. The permit applications for such projects must include professionally prepared landscape and irrigation plans showing that the landscaping will not exceed a maximum water allowance. A worksheet with water-budget calculations is also required. Some projects must install dedicated irrigation meters.

The Model Ordinance is aimed at eliminating inefficient irrigation. It prohibits overhead sprinkling in areas less than eight feet wide or within 24 inches of sidewalks and other nonpermeable surfaces. It also requires drip or other low-volume irrigation on slopes greater than 25%, and weather-based or evapotranspiration irrigation controllers for all automatic irrigation systems. Planting designs must group plants by water needs.

Several regional entities have worked together to develop local template ordinances to streamline requirements and achieve greater water savings. Members of the Bay Area Water Supply and Conservation Agency (BAWSCA) collaborated on a template designed to achieve up to 25% water savings on landscape projects. BAWSCA agencies receive Hetch Hetchy water from the San Francisco Public Utilities Commission, and are faced with limited water supply allocations. Additional regional template ordinances have been developed in Santa Clara County. Regional collaboration helps developers and architects by homogenizing requirements and presenting a consistent message of conservation to residents and businesses.

The state is also mandating that cities and counties adopt a first-in-the-nation mandatory Green Building Standards Code (CALGreen), setting energy, water, and overall-sustainability criteria for new construction. Since the required CALGreen standards and landscape ordinance face similar timelines for adoption, some agencies have opted to incorporate the landscape water-efficiency requirements into their update to the Green Building Program.

Catherine Elvert is a member of the Chapter's Executive Committee and a utility account representative for the City of Palo Alto Utilities. A version of this article appeared previously in the Sierra Club Bay Chapter's newsletter, The Yodeler.