The Marin Municipal Water District relies on rainfall for 75 percent of its supply. But this year rainfall is 50 percent below average so the district is tapping into one of its reserve back-up reservoirs.
Lake Phoenix is the second smallest of the district's five reservoirs on Mt. Tam and it sits downstream from the treatment plants so water will have to be pumped. The pumping, which began Thursday, will last 19 days and will cost an estimated $16,000 to power.
The water level of Lake Phoenix will drop up to 10 feet. The district's other reservoirs are at about 77 percent of capacity, thanks to higher-than-average rainfall last year offsetting this year's shortfall.
The district says it hopes to avoid rationing like the last time Lake Phoenix was tapped into in 1991.
"Well we don't expect to have to ration this year. But we are doing what we can to maximize our supplies this year so we're in the best possible position when the fall comes around, and we hope it's a rainy winter," said Libby Pischel, spokesperson for the water district.
The Marin Municipal Water District is 100 years old, making it the oldest municipal water district in California. It provides water for 185,000 residents of south and central Marin.