As yet another ferocious storm lashed San Francisco on Tuesday, the city received a record 662 reports of fallen trees, according to 311 data.
This is almost triple the previous record for the most fallen tree reports in a single day. That record was set earlier this year, with 229 reports during the Feb. 21 bomb cyclone.
Ominously, windy conditions could hit San Francisco again on Tuesday, March 28.
311 data has been collected for the past 15 years, but half of the top 10 days for fallen tree reports have come in the past three months. In the first quarter of 2023, there have already been more fallen tree reports than in any other entire year.
2023 has already seen more fallen
tree reports than any prior year.
Fallen trees reported to 311
2,200
2,000
Reports made on March 21
1,800
1,600
1,400
1,200
1,000
800
600
400
200
0
’10
’11
’12
’13
’14
’15
’16
’17
’18
’19
’20
’21
’22
’23*
Year
*to March 21
2023 has already seen
more fallen tree reports
than any prior year.
Fallen trees reported to 311
2,200
2,000
Reports made on March 21
1,800
1,600
1,400
1,200
1,000
800
600
400
200
0
’10
’11
’12
’13
’14
’15
’16
’17
’18
’19
’20
’21
’22
’23*
Year
*to March 21
Data from 311 calls.
Before we dive further into the data, it is worth noting that 311 calls are an imperfect way of gauging storm damage.
Trees reported as “fallen” may be badly damaged but still standing. Records may not capture every damaged tree, and conversely, there may be multiple reports of the same incidents. These calls can be filtered out of the data eventually, but as Public Works is still clearing up Tuesday’s uprooted trees, it is not yet clear how many of that day’s calls are duplicates.
Across the multiple storms San Francisco has endured this year, around a quarter of calls were ultimately flagged as duplicates. If this pattern holds true for this week’s storm, then the number of trees reported to have fallen on Tuesday will still shatter previous records, at a little under 500 unique incidents.
Even accounting for likely duplicate calls,
Tuesday’s storm almost certainly smashed records.
Fallen trees reported to 311
Unique calls
Duplicate calls
700
Likely duplicate
calls during
Tuesday’s storm
600
500
Mar 21
400
Jan 4
300
Mar 14
Feb 21
Jan 10
200
100
0
January
March
February
Even accounting for likely
duplicate calls, Tuesday’s storm
almost certainly smashed records.
Unique calls
Duplicate calls
Fallen tree reports
700
Likely duplicate
calls during
Tuesday’s storm
600
500
Mar 21
400
Jan 4
300
Mar 14
Feb 21
Jan 10
200
100
0
January
March
February
Data from 311 calls.
The destruction hinted at in the data was palpable in the Mission this week, where broken trees and snapped branches littered parks and streets. Some 38 reports came from the Mission, giving it the highest tally of any city neighborhood.
In Garfield Square, one of a pair of giant sequoias was mortally wounded during a February windstorm. The surviving tree dropped a large branch on the roof of the pool on Tuesday.
“These sequoias might be the oldest living residents of the Mission,” said local resident Edward Hasbrouck, who took photographs of the damage. The age of the trees is uncertain, but they may date to the park’s founding in 1884.
Falling trees pose a major hazard during a storm, both from striking people and from knocking out power lines. Roughly 70 of Tuesday’s 311 reports discussed potential damage to cars or other vehicles. Around 40 mentioned trees threatening to damage power lines.
According to the Mayor’s Office, at least two people died due to the storm on Tuesday. They were reportedly killed by falling trees. Many more people were injured, including SFPD Sgt. Kevin Brugaletta, who was badly hurt when a tree crushed his city vehicle.
At the peak of the storm, some 35,000 city residents were without power.
Why was the damage so severe?
According to the National Weather Service, winds of up to 88 miles per hour whipped through the city on Tuesday. This was caused by a rapid decrease in air pressure. Sensors at San Francisco International Airport recorded a low of 985 millibars, the lowest pressure ever recorded at the site in March.
As well as uprooting trees, the powerful gusts smashed windows, swept away boats, and even sent at least one couch hurtling through the sky.
It is difficult to attribute any one instance of bad weather to climate change, but experts say that the risk of extreme storms in California is rising as the planet warms. A day before the storm, the United Nations published a major report which stated that current warming has meant “more frequent and more intense extreme weather events” harming people across the globe.
Areas of the city with lots of ficus trees, sometimes called fig trees, may also have seen more damage from falling trees. Public Works has previously said that these trees are at greater risk of breaking in high winds. Ficus trees have been marked for expedited removal since 2014, although there has been community pushback in some instances.
According to data from Public Works, there are a little under 10,000 ficus trees in San Francisco. The 311 reports do not typically report what kinds of trees have fallen, although at least three reports on Tuesday specifically mentioned ficus trees.
What is being done to clean up?
Rachel Gordon, spokesperson for Public Works, said that “more than 900 incidents” were added to the department’s work queue between Tuesday afternoon and Wednesday afternoon.
“We had crews, both in-house and contractors, working overnight and all day today,” she said.
Public Works is responsible for clearing up trees on San Francisco’s public streets, while the Parks Department has jurisdiction over the city’s public green spaces. Gordon said that Public Works is triaging incidents to deal with the most dangerous ones first, including downed overhead wires and trees that hit cars or buildings.
“Trees not posing an immediate hazard are noted, but may not be cleaned up for days or weeks,” said Gordon.
To see where trees were reported as badly damaged or felled on Tuesday and throughout the city’s tumultuous past few months, take a look at our map.
Data from 311 calls.
I understand the high winds were the cause of the trees’ loss and damage, but many trees are not well-maintained. What preventative measures in regard to tree care might minimize or prevent damage in some instances?
I live in a home adjacent to a backyard poplar that is higher than a 3-story building, and likely at least 60-70 years old. At the height of last week’s storm, I was quite concerned (terrified at one point) that the tree would be uprooted – or falling in a direct path to my bedroom, would crash onto our house!
The absent property owner as NEVER taken care of the tree. It’s limbs and large branches are now entwined with highly-invasive morning glory vines, and I’ m concerned this will weaken the tree.
Stellar article. These super bomb storms have done drastic damage to existing urban trees across the city. It makes complete sense. I’ll break it down: after multiple years of unprecedented drought stress, even mature trees with established root systems are impacted. Even before the excessive rainfall and monster winds, mature trees were dropping major branches at a more frequent rate than previously. Combine the impact of drought stress with negligent care and deferred maintenance of city trees by the city. And then add in the compromised soil, excessive rain and wind resulting in pudding like heavily saturated ground combined with monster winds (70-85mph) plus overloaded (resulting in increased weight) branches from excessive rains and you have mucho tree carnage. Pity the birds.
I wonder what is the oldest tree in the Mission? Some of the palms in Dolores Park could possibly be older than the Garfield Park Sequoia, which appears to have been planted some years after the park’s 1888 inception, judging from the 1938 aerial photo. Always possible there’s a backyard contender.
I sure hope they let the Sequoia remain as it’s not at catastrophic risk like its tri-trunked sister was.
Here’s a pic of freshly planted in palms in Dolores from 1909:
https://burritojustice.com/2009/07/31/know-your-trees/
We lack the capacity to care for the street trees we already have.
The Bureau of Urban Forestry has a backlog from here to L.A.
Our choices for street trees have come back to bite us.
Let’s plant even more trees so that we can feel good about ourselves!!!
so sad! SF is one of the un-greenest cities anyways, it has a very, very low urban canopy cover even in comparison to L.A.. so this really hurts!
\
Perhaps planting and growing trees shouldn’t be priority in a densely populated city located at the tip of a peninsula known for sometimes strong winds, especially when hardly anyone has the time, money, or inclination to prune and care for trees — especially street trees? SF had hardly any trees in the early 1800s before colonization etc. and maybe that was because that’s the way the landscape and environment here should be.
well, there were hardly any people before you and your ancestors came… what kind of reasoning is that??? L.A. hardly had any trees neither did Sacramento. Mexico City didn’t have much of a tree cover either.
it’s the total lack of maintenance which led to the high tree failure here in SF. there was hardly any fallen or damaged trees in the more affluent areas of SF, like Pacific Heights even though they have the same species of trees especially ficus. the building owners took care of the trees and didn’t let them grow to 40ft and higher.
and now that the City is in charge it’s getting worse. i watch the “arborist” team in wonderment when they trim trees. they only thin them out but not capping the height. it’s lazy work done by unskilled workers.
While location has a point about local vegetation, trees do help with everything from air pollution to privacy even here in San Francisco. Hence groups like The Friends of the Urban Forest