Rim Fire: Update on San Francisco Water Supply

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Smoke from the Rim Fire rises above a ridge in Yosemite National Park on Wednesday, Aug. 21. The view is across an area of the park that burned several years ago. (Dan Brekke/KQED)
Smoke from the Rim Fire rises above a ridge in Yosemite National Park on Wednesday, Aug. 21. The view is across an area of the park that burned several years ago. (Dan Brekke/KQED)

Update 3:10 p.m. SF not "scrambling" to relocate water supply, says SFPUC

We've seen some headlines out there about the Rim Fire threatening San Francisco's water supply as it moves closer to the Hetch Hetchy Reservoir. AP wrote that water officials "were scrambling to fill area reservoirs with water from Hetch Hetchy before ash taints supplies." This morning, on KQED's "Forum," SFPUC General Manager Harlan Kelly said the agency was indeed concerned that the ash produced by the fire would eventually work its way into the water supply.

Charles Sheehan, spokesman for the San Francisco Public Utilities Commission, told KQED's Dan Brekke this afternoon that "there is some ash but most of the water is clear.” And he also emphatically denied the city was “scrambling” to move water into other reservoirs. Sheehan said that San Francisco had started to ship water from Hetch Hetchy to its Bay Area reservoirs as part of a seasonal move to begin to free up capacity at Hetch Hetchy in anticipation of the upcoming rainy season. He emphasized that those water shipments were standard practice for this time of year.

Sheehan also told Brekke that water officials have seen no indication of a change in quality of Hetch Hetchy water. He said remote monitoring is ongoing all along the system, and so far there’s no sign of any change in the level of particles in the water. He mentioned, as many others from SFPUC have, that water from Hetch Hetchy is drawn through an outlet 270 feet below the lake surface. That’s relevant because it means the water there is more likely to be free of contaminants.

“It’s a bit too soon to speculate” on the longer-term impact on water quality or how the city would address it, Sheehan said.


You can see the latest data on the water level at Hetch Hetchy at this California Department of Water Resources link.

Update: 1 p.m. The latest from AP:

Containment of the Rim Fire more than doubled to 15 percent, although it was within a mile of Hetch Hetchy Reservoir, the source of San Francisco's famously pure drinking water, officials said Monday.

"Obviously, it's the water supply of the city of San Francisco, so we're paying a lot of attention to that," said Glen Stratton, an operations section chief on the fire.

The fire, which has grown to 234 square miles in size, also posed a threat to giant sequoias in Yosemite National Park. Crews were using sprinklers and lighting fires to clear brush, though the fire remained several miles from the massive trees, Stratton said.

Julie Hutchinson, battalion chief for Cal Fire in Riverside, said on KQED’s "Forum" this morning that the weather is the wild card in fighting the fire. “A wind shift in any direction can cause the fire to make runs in the direction that the wind is pushing it," she said.

Also on on "Forum" this morning, San Francisco Public Utilities Commission General Manager Harlan Kelly said that the fire's close proximity to Hetch Hetchy has not affected the ability to deliver water and power to meet the city's needs. But he also said the agency was concerned about the ash produced by the fire that would eventually work its way into the water supply. More from AP on this aspect of the story ...

Ash from the 234-square-mile fire has been falling on the reservoir, but so far hasn't sunk far enough into the lake to reach intake pumps, Kelly said. Water quality remained good on Monday.

San Francisco gets 85 percent of its water from Hetch Hetchy as well as power for municipal buildings, the international airport and San Francisco General Hospital.

Kelly said on "Forum" that two of the three area plants used to generate power for the city have been taken offline. The remaining plant is producing less than a third of the power the city typically needs, he said, and power purchased on the open market is being used to make up the gap.

While Berkeley's Tuolumne Family Camp was destroyed by the fire (info on refunds at the city of Berkeley's website), San Francisco Rec & Park is reporting that the city's Camp Mather site has sustained only minor damage. The Strawberry Music festival, however, scheduled for Aug. 29 to Sept. 2 at the camp, has been canceled.

As far as Yosemite National Park goes, the National Park Service says that as of 9:30 a.m. most of the park was not affected and is "relatively smoke free." However, there are multiple closures of roads, campsites, trails and other attractions. Look at the National Park Service's Rim Fire update page to find out what those are.

Meanwhile, the White House announced today that President Obama had called Gov. Jerry Brown for an update on the fires. Brown got his own briefing at a fire base camp today. Said Brown ...

In other fire news, some evacuated residents from communities like Pine Mountain Lake are now returning. Fire officials say crews defended the town with a fire break that slowed the spread of the blaze. Maggie Dowd, a Groveland district ranger for the Stanislaus National Forest, said residents had done a lot to minimize damage from fires by limbing trees and clearing brush around their homes.

"I live in Pine Mountain Lake," Dowd said, "and as a resident we are expected to do defensible space every year. We have a certain period of time to do that, and if we don’t, then we are fined. And I think that over the past couple of years they’ve had a lot of success with residents, and if fire was to come to that larger community it wouldn’t have engulfed it as it has in other populations."

Monday, 8:10 a.m.: Fire officials say the fire has now burned just under 150,000 acres. That moves the Rim Fire up to No.13 on Cal Fire's list of the biggest fires in state history. The blaze is also now the biggest recorded in the Sierra Nevada since at least the 1930s, the earliest date on the Cal Fire list. The state fire agency warned in an advisory early this morning that conditions today will continue to be tough: "Winds again today will pose a challenge with gusts of 26 mph out of the south, pushing the fire further to the northeast."

The good news this morning: Cal Fire says containment on the fire doubled this morning from 7 percent to 15 percent.

In other developments early Monday:


  • Earlier update: (11:45 p.m., Sunday, Aug. 25): Federal and state fire officials say the Rim Fire has now burned about 144,000 acres, or 225 square miles. That makes it the 14th biggest fire in California history (or at least since 1932, according to Cal Fire's official list). But that total also signals a slowdown in the growth of the fire, which trebled in size from Wednesday into Thursday, then more than doubled again from Thursday through Friday evening. More than 2,800 firefighters are battling the blaze, which is 7 percent contained. Crews made enough progress on securing firelines that officials Saturday evening lifted an evacuation advisory for two communities, Pine Mountain Lake and Buck Meadows. About 4,500 residences are still threatened. Officials say 23 structures have burned, including at least four homes. Despite tentative signs of progress in fighting the blaze, officials say the fire is far from tamed. From the latest Associated Press report:

    Overnight the fire grew 7 square miles as firefighters gained little ground in slowing the now 207-square-mile blaze, said Daniel Berlant of the California Department of Forestry and Fire Protection.

    "Today, unfortunately, we are expecting strong winds out of the south," he said. "It's going to allow the fire to advance to the northeast."

    Fire officials are using bulldozers to clear contingency lines on the Rim Fire's north side to protect the towns of Tuolumne City, Ponderosa Hills and Twain Hart. The lines are being cut a mile ahead of the fire in locations where fire officials hope they will help protect the communities should the fire jump containment lines.

    The high winds and movement of the fire from bone-dry brush on the ground to 100-foot oak and pine treetops have created dire conditions.

    "A crown fire is much more difficult to fight," Berlant told The Associated Press Sunday. "Our firefighters are on the ground having to spray up."

    Other details:

    • San Francisco officials said Sunday the fire still has had no impact on the quality of water from the city's Hetch Hetchy Reservoir.
    • They added that utilities crews are returning today to the Kirkwood Powerhouse, shut down last week when the fire swept through the canyons downstream from the reservoir, to start repairs. A second generating facility, the Holm Powerhouse, was also shut down. Crews haven't been able to make it back to that facility to assess any fire damage that occurred there. The generating stations normally supply power to the Municipal Railway transit system and a wide array of other municipal facilities, including San Francisco's City Hall and San Francisco General Hospital. The city says it has spent $600,000 so far to buy power to replace the normal supply.
    • Tuolumne County education officials have canceled school for tomorrow and Tuesday. That's partly out of concern for the difficulty of traveling through some areas of the county and party because of smoky, unhealthy air in the area.
    • Officials in Yosemite National Park are taking special steps to protect the two groves of giant sequoias that the fire could threaten. Crews have cleared brush from around trees and installed sprinklers in the Tuolumne and Merced groves just in case. "All of the plants and trees in Yosemite are important, but the giant sequoias are incredibly important both for what they are and as symbols of the National Park System," park spokesman Scott Gediman told the Associated Press.

    More on the fire:

    KPCC's "Fire Tracker" graphic summary of the blaze:

    Earlier post (Saturday, Aug. 24): Acting on a request from San Francisco officials, Gov. Jerry Brown has issued an emergency declaration to help the city cope with the Rim Fire's potential impacts to the Hetch Hetchy water and hydropower system. City utility officials shut down two of the system's three powerhouses and nearby electrical transmission lines last Saturday as the fire began to sweep through steep, heavily wooded terrain west of Yosemite National Park. The power generated in the system is used to run the Municipal Railway transit system, City Hall, police and fire stations, San Francisco General Hospital, San Francisco International Airport and other municipal facilities. For now the city is replacing that electricity by using power banked with PG&E or by buying it from other suppliers on the open market.

    Michael Carlin, deputy general manager of the San Francisco Public Utilities Commission, told us this afternoon that there's no suggestion in the emergency declaration — or in the potential damage to the city's electricity-generating facilities near Yosemite — that power will be interrupted to San Francisco.

    In other developments Saturday:

    • The joint federal/state fire command says the fire has burned 125,620 acres—about 200 square miles. That's more than four times the area of San Francisco or equivalent to the entire area of San Jose and Santa Clara.
    • Fire officials reported the fire is 5 percent contained. They continue to rate the blaze's growth potential as "extreme" due to inaccessible terrain and very dry conditions.
    • Officials say 23 structures, including four homes, have burned. AP reports 5,500 homes are threatened, and officials have issued evacuation advisories for several towns and hamlets west of Yosemite. Resorts and summer camps in the area have also been shut down.

    Brown's Friday night declaration, which cited the possibility of a temporary interruption to power and water deliveries from the Hetch Hetchy system, frees state resources to help the city deal with any damage to its infrastructure. The state declaration also makes it possible for the city to ask for federal aid.

    Michael Carlin, the SFPUC's deputy general manager, said that utility crews are in the fire zone today to try to assess the condition of power facilities shut down last weekend after the fire started. Carlin said a full assessment of 12.5 miles of transmission lines and two powerhouses probably won't be finished until Monday or Tuesday. Crews are visiting the Kirkwood powerhouse, 12 miles below O'Shaughnessy Dam, to see how much damage it sustained as the fire burned in the area. Inspection of power lines and the Holm Powerhouse, downstream of the system's Cherry Lake reservoir, is on hold today. Carlin said crews are checking the condition of service roads and other forest routes and waiting for an all-clear from fire officials to access the area.

    As far as the city's Hetch Hetchy water supply goes, Carlin said there's no sign yet the fire has affected water from the system's main reservoir behind O'Shaugnessy Dam. He said the reservoir has been off-limits to everyone but fire personnel, "So we've had no eyes on the water there." But he said remote monitoring of the water supply at the Kirkwood Powerhouse and at other downstream locations has shown no change in the water's clarity. City officials have noted that Hetch Hetchy water is transported toward the Bay Area in underground pipelines and should be safe from ash and debris.

    Carlin said if Hetch Hetchy water quality is seriously degraded, the city would tap its water resources closer to the Bay Area—San Antonio and Calaveras reservoirs in Alameda County and the Crystal Springs reservoirs in San Mateo County. Customers would get at least 36 hours' notice if that happens, he said.

    An interruption of the flow of Hetch Hetchy water would reach far beyond San Francisco. The system serves not only the city's businesses and 800,000 residents, but also 1.7 million people on the Peninsula and Alameda County.