I was driving west along Clarendon Avenue, heading homeward. As I slid into the turn lane to make a right on Christopher, something white lay on the side of the road. I slowed nearly to a stop, unsure what it was. Then I recognized it as a barn owl, wings spread. My fear was that it might be injured, perhaps from hitting a car.
To my relief, it rose into the air and disappeared into the trees of Sutro Forest, a rodent clutched in the talons of its right foot. It must have just caught it.
But I was in even more luck! As I turned right, it sailed out of the forest ahead of me, looped over Christopher Dr, and flew back to a tree beside the street. Then it took off again, but only went a little deeper into the forest.
Later, I went back. The owl was there, but difficult to see in the darkness. I heard rustling sounds that suggested it was eating the rodent it had caught. I tried getting photographs, but both my phone and camera rebelled at the darkness. This picture is an edited public domain photograph.
This article is taken (with permission) from the SaveSutro.com website. It says UCSF’s Plan for Mount Sutro – which could start as early as this winter – could directly increase the risk for our neighbors on Christopher and Crestmont.
I started thinking about it. It’s a pretty insidious. The cutting of trees, and widening of the road to use heavy machinery and trucks up above our neighborhood could have very long-lasting effects – for five to ten years after the project, according to the research. Nothing might happen immediately – and then along comes a really wet stormy winter and whoosh!
Is this something real estate agents will have to disclose? I don’t know. And if something does happen – what’s the insurance situation? (I’m not even going to think of the risk to families living there.)
Anyway, this article is to let our Crestmont and Christopher neighbors know about these concerns. There’s more about the UCSF 2017 Plan on SaveSutro.com
Recently, we wrote that the Sutro Forest 2017 Plan Imposes a Landslide Risk. A University of Washington study shows that mudslides are most like 5-10 years after trees have been cut down on slopes. The picture below shows the South Ridge, which will be directly affected.
But it’s not just the tree-cutting. UCSF is widening two major trails into roads fit for heavy equipment, and adding nine quarter-acre “staging areas” for machines and felled trees. Both the roads are above Forest Knolls. (The heavy yellow lines in the map below are the new roads. The red squares are the locations of the staging areas, each of which will be a quarter acre.)
The picture at the top of this article gives some indication of how steep the hillside is. And the roads above Forest Knolls are atop a slope *known* to be unstable. Look at this landslide hazard map:
The double black arrows show landslide direction. The wiggly black arrows show soil creep direction. All those dark green areas? Potentially unstable. All the gold areas? Also potentially unstable.
Though the Draft Environmental Impact Report claims it’s making safety its first priority – it doesn’t look like it. In attempting to mitigate one (overstated) concern (dead trees falling), they’re worsening the risk of landslides.
Yesterday, I was horrified to receive this letter from some Forest Knolls neighbors. This is re-posted with permission. We stand with them against hatred.
[Edited to Add: If you want to email them in support, please use this email address: TamayoLee2017 at gmail.com ]
First Amendment Rights are being threatened here in Forest Knolls.
We are writing to you to seek your support for ensuring that residents of our neighborhood can express themselves without threats or fear of harm. Since late 2014 or early 2015 we have had a Black Lives Matter poster in our living room window at 11 Christopher Drive. No incidents have occurred because of the sign.
However, in mid-July 2017 we received an anonymous note in the mail addressed to “RESIDENT, 11 CHRISTOPHER DRIVE, SAN FRANCISCO, CA 94131” with the message “BLUE LIVES MATTER! Get rid of your sign, or WE will!”. We did not take any action at that time.
However, another note was mailed addressed to ‘BLM, 11 CHRISTOPHER DRIVE, SAN FRANCISCO, CA 94131″ postmarked August 14, 2017 – the Monday after the tragedies in Charlottesville, VA — which stated “It’s time to replace your BLM sign. How about CHINK LIVES MATTER”. (“Chink” is an anti-Chinese slur originating from the turn of the 20th century.) We reported these notes to the FBI and to the SFPD Park Station on August 17. We surmise that the notes were from someone who passes by our house on a regular basis and is aware that we are of Asian descent.
We placed the BLM sign in response to a national concern that African-Americans were not only victims of deadly violence but also suffered ongoing discrimination and disparities in health, education, job opportunities, etc. In June 2015, nine African-American members of an African-American Methodist church in Charleston, South Carolina were murdered in cold blood by an avowed racist. And as the recent events in Charlottesville point out, our concerns of a rising intolerance to people of color and immigrants are not unwarranted. We are sharing this experience with you as our neighbors so that we can ensure that all our lives are safe and that we can all continue to exercise our rights to post the BLM sign or display any other political statement of our choosing. (The sign was taken down in August as a safety precaution for houseguests, but it will be back up very soon.) We also want to make sure that our neighbors and other San Franciscans are not silenced.
We have lived at our house since January 1993, nearly twenty-five years. We have enjoyed our home, tending our colorful flower garden, creating art on our side fence, walking in the newly expanded trails of UC’s forest and meeting others at the reservoirs/ Tank Hill with our dog as well as at Forest Knolls back bench social and summer street parties. We are natives of San Francisco and our children have attended SFUSD from kindergarten to senior year.
Debbie is a Senior Vice President for Futures Without Violence, a national non-profit addressing domestic and sexual violence and child trauma, where she has worked for over thirty-five years. She and her mother have tended our front garden over the last fifteen years. Bill is the District Director for the U.S. Equal Employment Opportunity Commission and earlier served as the EEOC Regional Attorney for twenty years. Civil rights protections are very close to our hearts and we have dedicated our whole professional lives to that cause.
We have contacted Supervisor Norman Yee’s office and plan to meet with him soon. We are open to your ideas and suggestions to send a message that our neighborhood supports First Amendment rights and will not allow residents to be intimidated with racist threats. If you want to post a Black Lives Matter sign or any other sign to express concern and/or outrage, please do not hesitate to contact us.
Thank you for your support.
Bill Tamayo Debbie Lee Celi Tamayo-Lee
This article is reprinted from SaveSutro.com with permission. The landslide hazard described touches our neighborhood; Christopher Drive and Crestmont are both in Forest Knolls!
This is risk that may actually increase over the years as a result of actions being taken now, for two reasons.
First, tree roots take time to die and rot, but when they do, they weaken the living geotextile that stabilizes the hillside.
Second, trees take up water and help to regulate moisture deep in the ground. When large trees are cut down and stop doing this, small saplings and ground cover are not an effective substitute. So if the trees are cut in dry or normal years, nothing may happen for a while – and then a really wet year can trigger landslides that would not have happened if the trees had remained.
We’re reading the Draft Environmental Impact Report (DEIR) for the 2017 Sutro Forest Plan, and got to the section on landslide risk. This has been one of our concerns, especially since the tragedy at Oso, Washington, where the felling of trees in previous years was a factor in destabilizing the slope. (We wrote about that HERE: Cut Trees, Add Landslide Risk) We know this area is subject to landslides – we had a blue tarp covering unstable areas in Forest Knolls for a year when cutting trees destabilized a slope, and another just above UCSF’s Aldea housing area.
SHOCKING LANDSLIDE INFORMATION
We were shocked at what we found in the DEIR: “Increased instability could cause a landslide that would impact Crestmont Drive, Christopher Drive, and Johnstone Drive. An existing landslide scarp is visible above Christopher Drive. Some homes along Christopher Drive could be placed at additional risk from localized landslides due to plan implementation. Phase I activities would result in a potentially significant impact…”
The map above is taken from the DEIR. All the dark green areas are potentially unstable. All the gold areas are potentially unstable. All the cream areas are potentially unstable. The little red blobs and stars are already unstable. The black arrows show the direction of potential landslides – right into our communities. Here’s the key to the map. The light yellow and light green areas are where they are cutting down trees in Phase I (five years, starting this fall – 2017):
What’s the proposed “mitigation”? Avoiding work in the forest for 2 days when the soil is wet after rain. This completely ignores the fact that landslides are a MULTI-YEAR hazard after tree removal.
Here’s the proposed mitigation in their own words:
“After a significant storm event (defined as 0.5 inches of rain within a 48-hour or greater period), the following conditions shall be met prior to any vegetation management activities:
The maps detailing areas of historic slope instability or rock fall in the Final Geotechnical and Geological Evaluation Report for UCSF Mount Sutro shall be reviewed (Rutherford + Chekene 2013)
If ground-disturbing or vegetation removal activities are proposed within or adjacent to areas of historic slope instability or rock fall, the saturation of the soils shall be estimated in the field; if muddy water drips from a handful of soil, the soil is considered saturated (Brouwer, Goffeau and Heibloem 1985)
The areas of historic slope instability or rock fall shall be flagged if the moisture content of the soils is determined to be high (i.e., muddy) and ground-disturbing or vegetation removal activities shall be avoided for a minimum of 48-hours after a significant storm event to permit soil drying…”
In other words, we won’t chop down trees in the rain or when the soil is wet.
Other mitigations are palliative. They’re planning to build roads into the forest for trucks and heavy equipment, and those roads will follow the contour of the slope. The quarter-acre staging plazas – where they’ll remove trees so trucks can turn around and heavy equipment be parked – will be flattish, with a slight slope for drainage. None of this is as effective as not building these roads or bringing in heavy equipment in the first place.
WHY THE MITIGATION IS MEANINGLESS
The problem is, the effect of cutting down trees is a LONG TERM problem. The effect of tree removal takes years – not days, not months – to fix. In Oso, Washington, the slope gave way three years after the last tree-destruction. Here’s the story (from the article we published at the time). The tragedy was foreseen… but the regulators thought they had enough mitigations in place.
On March 22, 2014, a huge landslide destroyed the small Washington community of Oso. Rain was of course a factor, as was erosion at the base of the slope. But it’s probable that tree-cutting above the slide area was an important factor too. An article in the Seattle Times that quotes a report from Lee Benda, a University of Washington geologist. It said tree removal could increase soil water “on the order of 20 to 35 percent” — and that the impact could last 16-27 years, until new trees matured. Benda looked at past slides on the hill and found they occurred within five to 10 years of harvests [i.e. felling trees for timber].
There had been red flags before. The area was second growth forest, grown back from logging in the 1920s/30s. Over 300 acres were again logged in the late 1980s.
The first time regulators tried to stop logging on the hill was in 1988. But the owner of the timber successfully argued that measures could be taken to mitigate the risk. Eventually, the state only blocked it from logging some 48 acres, and the owners gave in on that.
In 2004, new owners applied to cut 15 acres; when the Department of Natural Resources (DNR) objected, they halved the area and re-located the cut. DNR gave approval, subject to no work during heavy rain and for a day afterward. The tree-cutting finished in August 2005.
In January 2006, there was a major landslide 600 feet from the cut zone. The state built a log wall to shore up the slope.
The owners continued logging. In 2009, they removed 20% of the trees. In 2011, they removed another 15%. In 2014, the hillside collapsed.
The regulators were aware of the risk; they thought they were mitigating it with their restrictions and reaching a compromise with the owners. But it wasn’t enough. Destabilizing the mountainside is a long-term thing; the effects can show up in months, but it’s more likely to take years.
THE LESSON FOR MOUNT SUTRO
Our mountains not only are potentially unstable, they actually have landslides. The picture at the end of this article shows one on Twin Peaks, where rocks tumble after nearly every heavy rainy season.
The roots of the trees are helping to hold the unstable soil in place and that as the roots rot, landslide risk will increase. It is going to be more unstable 2-3 years after the trees are removed than 2 days after it rains. The information that instability increases over time is a little counter-intuitive.
Moreover, removing the trees takes away their ability to suck water out of the soil. If the tree-cutting is done in dry years, it may take a wet winter to trigger landslides… which would not have happened if the trees had been regulating the water and functioning as a living geotextile.
Since UCSF are not going to use herbicides on the stumps to prevent them from resprouting, they say they will grind the stumps. That is an effective way to prevent resprouting, but it will greatly increase the instability of the soil because the heavy equipment digs down several feet into the stump to destroy the roots. That’s another reason why they should not destroy trees where slide risk has been identified.
Anyone seriously considering the map above can only hope that UCSF will draw a better conclusion than the Washington State loggers and regulators. The planned destruction of thousands of trees – many within the first five years – could cause landslides in surrounding communities not days or months later, but years after the event.
We’ve known for years that coyotes are all around us in Forest Knolls – I wrote about it here when a couple of neighbors reported seeing them. (LINK: Coyotes Among Us)
But this time, neighbor Michelle Lukban got this really neat picture (published here with permission). For everyone who’s been jealous of Bernal Heights coyote pictures, we got ours! [Edited 3/27/17 to correct attribution of picture]
BEING CAREFUL AROUND COYOTES
Janet Kessler, the Jane Goodall of SF’s coyotes, has for many years been observing, photographing, and reporting on our San Francisco coyotes. Her website is at CoyoteYipps.com. She’s also involved with Coyote Coexistence, an organization that helps people and coyotes to co-exist safely.
Coyotes are not very concerned about people, and are generally quite shy of them. But they are very interested in dogs. Coyotes are territorial animals, and dogs could be considered interlopers. Also, some dogs chase coyotes, and so coyotes may feel threatened. Often the coyote will remember which dog it was. Don’t let your dog do this. It could be dangerous for both animals. Finally, really small dogs – and cats – may be viewed as prey. This is rare, but it has happened. If you have pets, the video above may be useful.