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Yosemite fire 'size of Chicago'

A wildfire in Yosemite National Park in the US state of California has spread to almost 150,000 acres, according to fire service officials. A state of emergency has been declared for San Francisco after power lines servicing the city were threatened.

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Yosemite wildfire affects San Francisco water source

A raging wildfire in Yosemite National Park has rained ash on the reservoir that is the chief source of San Francisco's famously pure drinking water, according to the Associated Press.

The Rim Fire burns near Buck Meadows, California. Credit: Reuters/Max Whittaker

Utility bosses scrambled to send more water towards the metropolitan area before it became tainted as nearly 3,700 firefighters battled the 230-square-mile blaze, the biggest wildfire on record in California's Sierra Nevada.

"We're taking advantage that the water we're receiving is still of good quality," said Harlan Kelly, 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."

They reported modest progress, saying the fire was 20% contained.

Read: Yosemite fire 'size of Chicago'

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