My husband, fire ecologist and SF Chronicle columnist (Ask an Arborist, 1st Saturday of the month, plug plug) is quoted in this article on fire storms.
Wooded hillsides, narrow roads make Bay Area a 'disaster waiting to happen'Kevin Fagan, Chronicle Staff Writer
Thursday, October 25, 2007
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The right combination of the wrong conditions could create a firestorm in the Bay Area every bit as devastating as the one savaging Southern California, fire experts say - and nowhere is that danger more acute than in sleepy Mill Valley.
There, sprinkled throughout the lushly forested slopes of Mount Tamalpais, lie some of the Bay Area's most expensive houses. The beauty is double-edged: The same verdant slopes that draw the wealthy and the famous also harbor heavy underbrush and trees that have not burned for nearly 80 years. And the narrow, twisting roads that give the town's neighborhoods their charm would turn into death traps with the first wreck during an evacuation.
All that is needed to light up this residential wonderland would be a couple of weeks of hot sun, a strong easterly wind and a spark of some kind, experts say.
With enough bad luck, it could happen next month, after the recent rains dry completely off.
"The fire conditions there and on the mountain in general are absolutely horrendous," said Ray Moritz, a Sausalito-based fire ecologist who advises fire departments all over the Bay Area. "The fuel load (potentially flammable wood) is tremendous. It's a disaster waiting to happen."
The Bay Area's other hot zones of high risk are not far behind.
Similar conditions - houses nestled in thick growth on hillsides with hard-to-negotiate, narrow roads - exist in parts of Contra Costa, Alameda and San Mateo counties. A lot of progress toward standardizing fire hydrant fittings, radio communications and construction requirements has been made all over the Bay Area in the past 15 years, but in those three areas in particular, there is still a lot of catching up to do.
To residents, such areas are just enclaves of fine houses in beautiful wooded settings. Fire experts call them wildland interface zones.
"A lot of the hills areas in Berkeley and Oakland, in and around where that awful 1991 Hills Fire happened, are still at great risk," said Contra Costa County Fire Protection District Chief Keith Richter, who coordinates mutual aid for fire departments from Oregon to Monterey. "On the other side of the hills, in parts of Orinda, Lafayette and Walnut Creek, conditions are also ripe."
He said road widths of at least 22 feet, allowing for fire engine movement even in a jam, have become common in new construction sites. But there are still a lot of old neighborhoods in the East Bay hills where the modern era has not caught up.
"Areas like the little community of Canyon, the south ends of Lafayette and Orinda - those are real hot spots for us," Richter said.
If a blaze began chewing up the dry brush and oaks of Contra Costa badly enough, Richter said, most fleeing residents would be sheltered at schools with fields that could act as firebreaks, such as Stanley Middle School in Lafayette. Concord Pavilion could house thousands in a pinch.
On the other side of the hills, schools like Oakland Technical High School were evacuation points in the 1991 blaze. Oakland's Coliseum could act as a gathering point if things got chaotic enough.
There are those who lived through the 1991 disaster who have no doubt chaos would happen.
"There are quite a few spots where the city hasn't been able to widen the roads, and on the ones that have been improved, we now often have a problem of too many cars," said David Kessler of Oakland, who lost his house in 1991 and heads the North Hills Phoenix Association of fire-conscious residents. He pointed to Charing Cross Road, where six people died in narrow roadways trying to flee the Hills Fire.
"And on Bristol and Buckingham roads, the city has allowed a lot of big houses, and people park where they shouldn't.
"What if someone is holding a big party along one of those roads when a fire breaks out? Nobody will be able to drive past the cars, and we'll have the same disaster we had all those years ago."
Fire ecologist Moritz said the same concerns can be found in the San Mateo County hills around Woodside, though the danger of fatalities is lessened by the sparseness of the population there. Vaca Mountain, east of Napa, is also considered by fire experts a potential tinderbox, though it too, is thinly populated.
But when fire planners gather to ponder how best to gird for the next big blaze, Moritz and his fellows always pull out the map of Mill Valley and its surrounding communities.
The last big fire there was in 1929, and it burned 1,000 acres and 115 homes. Since then, the population of the area and the size and value of the houses have soared.
The worst-case scenario, Moritz said, would involve a major earthquake during high fire season. Considering that the Bay Area is overdue for a major quake by at least a decade, by many seismic estimates, this is not out of the question. The region's most catastrophic quake in modern times, Loma Prieta in 1989, and the most catastrophic fire, 1991's Oakland Hills Fire, both happened in October.
"If you get a big quake and fires break out, it would be impossible to block the advance of the blazes around Mount Tam," Moritz said. "The roads would be blocked or damaged by the quake, services cut off, emergency personnel overwhelmed handling the quake. Very quickly, the fires could get so powerful that dumping retardant on them with helicopters and airplanes would be like spitting on them."
That was the scenario in the 1991 Hills Fire, which turned 2,900 homes to ash and killed 25 people. The same thing happened in Marin County's worst fire, the Mount Vision Fire, in 1995. It roared out of control near Tomales Bay State Park for a week, destroying 12,350 acres, forcing 500 people to evacuate and destroying 45 homes. It's what's happening now in Southern California.
Mill Valley's 13,600 residents are particularly vulnerable to such a fire because the town is situated among canyons and arroyos that would turn into blowtorches in a major blaze. Many of the hillside streets are dead-ends and 4 to 10 feet narrower than the recommended 22-foot width. A skinny roadway means one good stall would put fleeing residents on foot and force fire engines to re-route, wasting valuable time.
"Say the fire begins with an offshore wind," Moritz said, like the one that helped spread the Mount Vision Fire. "It creeps downhill, then it gets pushed by one of our easterly winds, which are Marin County's version of the Santa Ana winds - hot, blowing in from the east and very strong.
"You could have fire burning from the top of the mountain, and from down below, and all those people on foot because the roads were blocked would be trapped in between them."
In a worst-case disaster, every town around Mill Valley would be subjected to flames, and the conflagration would end only when it had burned either to the bay on the east or the ocean on the west. Just counting the bigger towns from Kentfield to Sausalito and over the mountain to Stinson Beach, that means nearly 50,000 people and more than 23,000 homes would be at risk.
Those who live in the danger zone shrug off the nasty possibilities as part of the bargain for getting to live in one of the most desirable areas of the country; Mill Valley's median home price is $1.25 million. Most give at least some thought to preparation. But once you've cleared brush around the house, refitted the roof with fire-retardant shingles and the like, there's not much else to do but hope fate treats you kindly, they say.
"We're very focused on thinning our trees, keeping the roadways clear and cutting our underbrush, but not matter what you do, man takes a gamble when he comes into areas like this that are historically hot and have naturally occurring fire," said Barbara Sykes, 75, who has lived in her shingle-sided, hand-crafted mountain house on a slope overlooking Mill Valley since 1976.
From the sprawling porch at the back side of her home, Sykes has a view all the way to the Bay Bridge. Mill Valley looks like a fairyland of wooded cottages; the homes of rockers Sammy Hagar and Carlos Santana are minutes away.
"I'm a real nature lover," she said Wednesday. "But when that easterly wind starts blowing, I always realize that if a fire happens here, the best we can do is just try to get out of the way."
A few miles up Mount Tamalpais, at the Throckmorton Ridge Fire Station, Marin County Fire Department engineer Don Keylon cast a wary eye on how vigorously the winds were flapping the flags at the station entrance. The wind was blowing about 10 miles per hour, and he didn't like that.
"We regularly take the fuel moisture reading here, and the fuel load right now is at 64 percent," he said. That means the moisture is at 64 percent of normal in the wood.
"Sixty-six percent is what we consider critical, so I'd say we have to be pretty careful right now," Keylon said. He pointed to a wide canyon leading from Mill Valley straight up to his 900-foot-elevation station.
"If a fire comes up through one of the drainages (cuts in the land) down there, it'll be kind of like a chimney," he said.
"Like a blowtorch. Not good."
Past California wildfires
Some of the worst wildfires in California since the 1930s, based on deaths, destruction or acreage burned:
October 2003: Near San Diego; 273,000 acres; 4,847 structures destroyed; 15 deaths. Cause: accidentally started by a hunter. It was among 15 wildfires that killed 22 people, destroyed 3,640 homes and blackened 750,000 acres of Southern California over two weeks.
November 1993: Malibu area of Los Angeles County; 18,000 acres; 323 homes destroyed; three deaths. Cause: arson. It was among more than 20 fires that killed four people, destroyed more than 1,000 homes and consumed 193,814 acres over two weeks.
October 1991: Oakland hills; 1,520 acres; 3,276 homes and apartments destroyed; 25 people killed. Cause: A flying ember from a fire believed to have been contained ignited a tree.
November 1980: San Bernardino Mountain foothills east of Los Angeles; 23,600 acres; 325 homes destroyed; four dead. Cause: arson.
September 1970: San Diego County mountains; 175,425 acres; 382 structures destroyed; six dead. Cause: power lines.
November 1966: Near Angeles National Forest in Los Angeles County; 2,028 acres, 12 firefighters killed; Cause: power line.
November 1961: Los Angeles County; 6,090 acres; 484 homes destroyed; Cause: believed accidental.
July 1953: Glenn County, Northern California; 1,300 acres; 15 firefighters killed. Cause: arson.
October 1933: Los Angeles County; 47 acres; 29 welfare workers clearing brush killed. Cause: undetermined.
July 1929: Mill Valley; 1,000 acres, at least 100 homes lost. Cause: undetermined.
The Associated Press and Chronicle staff
E-mail Kevin Fagan at kfagan@sfchronicle.com.
