TUOLUMNE CITY — A raging wildfire in Yosemite National Park rained ash on the reservoir that is the chief source of San Francisco's famously pure drinking water, and utility officials Monday scrambled to send more water toward the metropolitan area before it becomes tainted.
Nearly 3,700 firefighters battled the approximately 230-square-mile blaze, the biggest wildfire on record in California's Sierra Nevada. They reported modest progress, saying the fire was 15 percent contained.
"We're not there yet, but we're starting to get a little bit of a handle on this thing," said Lee Bentley, fire spokesman for the U.S. Forest Service. "It's been a real tiger. He's been going around trying to bite its own tail, and it won't let go but we'll get there."
Utility officials monitored the clarity of the Hetch Hetchy Reservoir and used a massive new $4.6 billion gravity-operated pipeline system to move water quickly to reservoirs closer to the big city. The Hetch Hetchy supplies water to 2.6 million people in the San Francisco Bay area, 150 miles away.
"We're taking advantage that the water we're receiving is still of good quality," said Harlan Kelly Jr., general manager of the city's Public Utilities Commission. "We're bringing down as much water as possible and replenishing all of the local reservoirs."