Crews are continuing to inspect and repair two powers stations serving San Francisco that were damaged by the Rim fire.
The San Francisco Public Utilities Commission was forced to shut down two of its three hydroelectric power station transmission lines that bring power to the San Francisco area because of the fire. On Friday, Gov. Jerry Brown extended a state of emergency to include the city and county of San Francisco because of the threat to utilities.
Supplementary power has cost the San Francisco PUC $600,000 since the two stations were shut down last Monday, said Tyrone Jue, a spokesman for the agency. There is no timetable for when the stations will be back online, he said.
Crews have entered the Kirkwood Powerhouse, but unsafe conditions have prevented them from inspecting the Holm Powerhouse, Jue said. The Moccasin Powerhouse is still generating and transmitting power.
Customers have seen no interruption in electrical service, he said.
Officials are also monitoring the quality of water from the Hetch Hetchy Reservoir, only a few miles from the fire. The site's regional water system serves 2.6-million customers in San Francisco and the Bay Area.
“Transmissions are showing the water quality we have now is the same as it was before the fire started,” Jue said, adding that there are no concerns about damage to the water infrastructure, which is made of concrete and steel.
The city deployed five engine crews from the San Francisco Fire Department to Tuolumne County on Thursday to assist with structure protection. Staff from the PUC and Recreation and Parks Department are also assisting with road clearing, hazard identification and logistics.
More than 2,800 firefighters have been battling the blaze, which has scorched nearly 134,000 acres in and around Yosemite National Park. The fire is 7% contained.
About 15,000 acres of the blaze are burning inside the national park, a 3,000-acre increase from Saturday, said Park Ranger Kari Cobb. Yosemite remains open, though visitation is slightly down, she said.
“Once people are getting here, they’re seeing it’s open and operational, and the skies are still beautiful and clear,” she said.
The wildfire is burning in the northwestern portion of the park, one of the less-visited areas of Yosemite during this time of year because of the low elevation and heat, she said. Staff and visitors were moved out several days ago, she said.
No additional sites are threatened by the fire, though ground fuel was cleared and a sprinkler system was installed near two sequoia groves as a precaution, she said.
The entrance from Highway 120 on the west side of the park, the Hodgdon Meadow campground and the Hetch Hetchy backpackers’ campground remained closed Sunday. All other campgrounds are open. Popular areas in the park such as Yosemite Valley, Glacier Point, Wawona, Mariposa Grove, Crane Flat, White Wolf and Tuolumne Meadows were open Sunday.
The Black Oaks Casino Resort in Tuolumne County was advising visitors to stay away, according to its website.
Winds will be the biggest challenge for firefighters in the coming days. Ridge winds are expected to increase this afternoon and tonight, which could hamper containment efforts, said Kevin Durfee, a National Weather Service meteorologist in Hanford.
“It really looks like the weather is not going to be terribly cooperative in the next three days,” he said.
Winds could gust up to 30 mph in the area around the fire, and will remain strong Sunday and Monday, said Drew Peterson, a National Weather Service meteorologist in Sacramento.
Temperatures are expected to remain steady at normal to below normal, which means no excessive heat to dry out fuels, he said. Humidity will be about 20% to 25%, he said.
“It could be drier, much drier than it is. The main thing they’re going against is the winds,” Peterson said. “If they can make it until Tuesday, it looks like conditions will be better.”
Winds are expected to continue blowing from the south and southwest, so smoke should not be a problem where the bulk of Yosemite tourists are, Durfee said.
Aside from the rugged and hard-to-reach terrain, another difficulty is the blaze's tendency to burn the tops of trees, creating a "crown fire" with long, intense flames that skip across forested land faster than a wildfire that creeps along near the ground.
Firefighters are working to hold the fire east of the North Fork of the Tuolumne River, and crews have strengthened lines that are holding above the community of Pine Mountain Lake, the Forest Service said.
Crews are directly attacking some areas of the fire and will continue to do so as firefighters gain safe access. In areas with extremely rugged, inaccessible terrain, firefighters are creating control lines away from the active edge of the blaze. Air resources are also being used to slow the fire’s progress, the Forest Service said.