West Marin’s two largest water agencies—Marin Municipal and North Marin Water Districts—received new draft regulations this week from the State Water Resources Control Board regarding the percentage of water usage their service areas will have to reduce. But just as the board handed down its regulations, an Orange County court issued a ruling that could hamper attempts by local California agencies to disincentivize large water use. The Fourth District Court of Appeal ruled that charging heavy water users higher rates not tied to higher water costs in San Juan Capistrano violated California law, and in doing so set a potential precedent regarding tiered water-rate charges. Tiered charges are a major tool agencies have used to curb water usage during the drought, as higher charges for big consumers are intended to discourage excessive residential consumption. North Marin charges different rates for users in West Marin than it does in Novato, the district’s two service areas. The areas have separate water supply and distribution systems, said the district’s manager, Chris DeGabriele, who noted that it is too early to tell what implications the court’s ruling may have on West Marin. The district’s attorney is currently reviewing the ruling. Marin Municipal charges one tiered rate structure for its service areas, including West Marin’s San Geronimo Valley. The court ruling and the water board’s latest regulations follow an executive order issued earlier this month by Governor Jerry Brown, who called for a mandatory 25 percent reduction in urban water use across the state. This week, the board released draft regulations that widened the range of percentages under which local agencies must meet certain benchmarks for cutting back water use as compared to 2013. The cutbacks range from 4 percent to 36 percent, depending on the size of the agency and the amount of water its clients consume. To set benchmarks, the board computed a metric of percentages based on daily per-person water usage from July to September of 2014. North Marin will have to reduce water use by 24 percent compared to 2013. As of February, West Marin’s share of the North Marin is down 18 percent, though Mr. DeGabriele noted that water use in March increased slightly. He encouraged local customers to limit outdoor water use while the district awaits final regulations from the state. “To me, this is still a work in progress,” he said. “We’re better off to wait to see what’s adopted.” Marin Municipal, meanwhile, has reduced its water consumption by 15 percent since 2013 and will have to reach a 20 percent benchmark by next year. That district adopted a 25 percent voluntary water reduction in January 2014 and abides by similar water-use prohibitions as North Marin, including no irrigation between 9 a.m. and 7 p.m., no watering of sidewalks or driveways and no hoses without shut-off nozzles. “It’s not a huge reach for us to get there,” said Libby Pischel, Marin Municipal’s spokesperson. “We expect that we’ll be able to meet the requirement from the state.” The state board will hold a hearing and adoption of the draft regulations on May 5.