Sept. 18, 2024 

Changes align District with the state, simplify requirements for new construction

Corte Madera – The Marin Water Board of Directors on Tuesday adopted changes to the District’s water efficiency rules to simplify and streamline local efforts to reduce water use. 

Through adoption of an Ordinance, Marin Water will sunset requirements related to the inclusion of graywater systems in new home construction and substantial remodels, and institute the following changes focused on both indoor and outdoor customer water use:  

• A limit on grass installation at newly constructed single-family homes or duplexes  
• Alignment of the District’s plumbing fixture standards with state guidelines  

Inspired by California’s Model Water Efficient Landscape Ordinance, Marin Water’s new lawn guidelines cap the total allowable amount to no more than 20% of the newly landscaped area, with a maximum allowable grass area of 1,200 square feet. With lawns using substantially more water than low or very low water use landscapes, a limit on new installations will target a significant source of outdoor water use. The new rules apply to grass installed at newly constructed single-family homes or duplexes starting Jan. 1, 2025.  

This simplified approach also carries over to changes in the District’s requirements for plumbing fixtures. As approved by the Marin Water Board of Directors, local plumbing requirements will now be tied to the water efficiency standards set forth in the California Green Building Standards. These standards are updated periodically, and District requirements will keep pace with those updates. 

Although grass limits for new construction represents a change in approach from the prior graywater system requirements, the adoption of this new ordinance maintains the District’s efforts to reduce overall outdoor water use. Because graywater systems were often deemed non-feasible, the potential for water-savings from the previous requirements was limited. The new approach – a limit on grass installation at all qualifying new construction – will apply more broadly. 

“While well-intentioned, the District’s graywater requirements weren’t feasible for most new construction sites,” said Board President Ranjiv Khush. “This new approach simplifies the rules for builders and homeowners and shifts the focus of new development in central and southern Marin County away from lush, high-water using lawns to a more water-wise approach to outdoor landscaping.”