The governor had already declared an emergency for the area around the fire but extended it to San Francisco, saying the blaze posed a threat to the city's power lines and stations in the fire area.
The city gets 85 percent of its water from the Yosemite-area Hetch Hetchy reservoir and, that has yet to be affected. But San Francisco has been forced to shut down two of its three hydroelectric power stations in the area, and further disruptions or damage could have an effect on the power supply.
The hydroelectric power serves the San Francisco Muni Railway. So, the city is paying to buy power to keep things running. And the power problems don't end there.
The fire may be burning 100 miles from San Francisco, but it's still making city officials very nervous because it's coming a little too close to an amazing resource for water and power in the city.
Most people in San Francisco may not realize the water they drink could be impacted by that giant wildfire burning near Yosemite.
"Supposedly we have some of the best water in the country, so I think what they're doing is good. Obviously, I think it needs to be protected," San Francisco resident Phillip Brown said.
The San Francisco Public Utilities Commission has activated an emergency situation room to monitor the Rim Fire, burning near the Hetch Hetchy Reservoir, which provides water to 2.6 million people in the Bay Area.
Ash from the fire is the big worry. Its fallen into the reservoir, but according to digital gages the water quality is still safe.
"It doesn't happen immediately. We would actually see the cloudiness increase slowly in Hetch Hetchy Reservoir giving us sufficient time to make the adjustments to the system so there will be no disruption in water service to any of our customers," P.U.C. Chief Operating Officer Michael Carlin said.
However, Hetch Hetchy Reservoir is also a big source power. It keeps the lights on at every public building in San Francisco and keeps Muni rolling. Two out of three powerhouses are off-line as a precaution. Arcing power lines could endanger firefighters. PG&E is selling power to the city to make up for the difference.
But fires near the dam are nothing new.
"We have lived through this before, there have been other fires in the watershed in my tenure here, the same sort of event has occurred where we see cloudiness in the Hetchy water and we're able to monitor, manage and actually protect that water supply," Carlin said.
Water officials hope they can offer the same protection this time from a monster wildfire that's still raging.
