Marin Municipal Water District approves lawn limits

The Marin Municipal Water District has set tighter limits on the size of lawns for new houses.

The board’s unanimous vote Tuesday also updated the district’s standards for plumbing fixtures. The new ordinance, which will replace the district’s grey water ordinance, aims to simplify requirements for new construction and reduce indoor and outdoor water use.

Grey water is wastewater from bathtubs, showers, bathroom sinks and clothes washers. The grey water ordinance states that applicants seeking new water service, and projects requesting expanded water service for large residential or commercial remodels, must install a grey water recycling system for landscape irrigation.

However, the district allowed customers to self-certify whether a grey water system was feasible, resulting in many owners of eligible sites exempting their properties. That means the desired water savings from the ordinance isn’t being achieved.

The new ordinance instead limits the grass area of new houses to 20% of total landscaped area, or no larger than 1,200 square feet. That’s more restrictive than the state’s standard of 25%. State rules apply to all homes and residential complexes.

As for plumbing fixtures, the new district requirements will be tied to the California Green Building Standards Code, allowing the district to keep pace with the state, which updates the rules every three years.

The ordinance takes effect Jan. 1.

“While well-intentioned, the District’s graywater requirements weren’t feasible for most new construction sites,” Ranjiv Khush, the president of the district board, said in a statement after the board meeting Tuesday. “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.”

At the meeting, Khush asked staff to confirm that the new turf limits would reduce outdoor water use for new homes by about 50%.

Carrie Pollard, the district’s water efficiency manager, said that is the rough estimate.

Pollard said the ordinance prevents large swaths of lawns being installed in new construction so district staff could be relieved of the effort trying to get the homeowners to reduce their outdoor water use.

“This is an opportunity to address this up front” and “make sure they’re installing something efficient from the get-go,” Pollard said.

Board member Matt Samson asked if the Jan. 1 start date provides contractors and cities enough time to adjust to the new standards.

Pollard said the ordinance will only apply to building applications submitted after Jan. 1.

“No planning would have happened at that point for those new developments, so we feel that it’s appropriate,” Pollard said.

The water district serves about 191,000 residents in central and southern Marin County.

The county’s other water major water utility, the North Marin Water District, serves about 60,000 residents in the greater Novato area as well as about 1,800 residents in areas of western Marin.

The North Marin district allows no more than 25% of landscaped area, or up to 600 square feet, to be natural turf. In December, the district approved a ban on decorative grass on commercial properties, said Tony Williams, the general manager.

Williams said the district’s plumbing fixture standards already meet or exceed the state’s green building code.

“We regularly review our regulation and make updates as appropriate,” Williams said.