The failure of a rain gauge at Kent Lake to meet a key threshold has triggered voluntary rationing for North Marin Water District customers in West Marin, with mandatory rationing set to begin on July 1. The district’s water rights to Lagunitas Creek stipulate that the gauge needs to receive at least 28 inches of rain or more by April 1 to avoid rationing. This year it narrowly missed the requirement, with 27.6 inches. Even if the area receives more rainfall, the ordinance will remain in place. That water right “took into account… that even if there were subsequent rainfall, the aggregate would be a dry-year condition,” said Drew McIntyre, the chief water engineer for the district. This is the first time since the water right was adopted in 1995 that fewer than 28 inches of rain were measured at the gauge. The voluntary stage asks its customers in Point Reyes Station, Inverness Park, Olema, Bear Valley and Paradise Ranch Estates for a 15 percent reduction from April to June, compared to the same billing period last year. Starting July 1, and until the board passes a resolution ending the conservation ordinance, the district will require a 25 percent reduction compared to last year’s use. Non-essential uses of water, such as washing driveways and patios, refilling a swimming pool and car-washing, will be prohibited, even for those meeting the mandatory reduction. Still, any residential connection using less than 200 gallons a day—about 40 percent of West Marin’s 777 connections—will be considered in compliance with the ordinance. “We encourage them to do what they can and take additional measures where possible, but we recognize that they are doing a lot already,” Mr. McIntyre said. By the end of April, customers will be able to log into their accounts at nmwd.com and view a graph of their water use, as well as their reduction target.