The “Fire Hazard” that Wasn’t

UCSF applied to FEMA for funds on the basis that the forest had a Very Severe Fire Hazard. It doesn’t. (At least unless UCSF and the Mount Sutro Stewards implement the thinning and drying out of the forest.)

The website of California Department of Fire and Forestry states, regarding San Francisco County: “Update, 11/2008: CAL FIRE has determined that this county has no Very High Fire Hazard Severity Zones in LRA [Local Responsibility Area]. ” Cal Fire’s map shows the fire danger as its lowest rating:  “moderate.” There is no lower rating; the next is “unzoned.” (Other counties do show Very High fire hazard, both in Local Responsibility Areas and State Responsibility Areas so it’s not a glitch.)

http://frap. webdata/maps/ san_francisco/ fhszl06_1_ map.38.jpg

FEMA actually talked with CalFire about this discrepancy. Here’s what they found:

To put it simply: The CalFire map is the right one. The fire hazard is moderate, the lowest rating.

But…as we noted earlier, the planned projects could increase the fire hazard of the forest.


At present, the forest is like a cloud forest; it traps the moisture in the fog, so the ground is almost always damp in there. The fire risk is small;  thinning the forest would actually raise the risk.

We maintained a daily Fog Log for September, October, and November 2009 in response to a UCSF statement that the forest dried out in these months, and dry high-intensity northeasterly winds and high temperatures raised the fire risk. (Summary of the conclusions: the longest period the forest went without fog-drip or rain was seven days. There were no hot dry northeasterly winds. The forest remained damp.)


The project papers in the FEMA application overstate the fire-hazard. UCSF representatives distributed a “fire-map”, taken from San Francisco’s Hazard Mitigation Plan, prepared in 2005 by the private corporation URS for the Department of Emergency Management. However, the same document notes: “CALFIRE has no record of any wildfire in San Francisco.”]

And just to put it in context: Here’s what the Bay Area fire map from Association of Bay Area Governments looks like. There’s more risk in the bare grassy hills across in Marin, or down on San Bruno Mountain.

Bay Area Fire Risk: SF, not much


UCSF’s application to FEMA caused a lot of concern around fire hazard.  In fact, it did not substantiate the risk, and caused a lot of confusion. Three different sets of “fire-hazard maps” were used in the discussions. None showed that fire risk was Severe or that cutting down trees would lessen it. (If you want to read about the fire-maps, go here.)

Aside from the mysterious fire-maps, USCF’s argument about fire risk was based on the following.

1. There was a 60 acre fire in 1899.

Aside from the fact this was over 100 years ago, the terrain at the time was very different from what exists today. Tree planting only started in 1886. The trees, if they existed at all, must have been much younger, with large expanses of open flammable grassland.

2. There were other, small fires when the forest was being logged, including one in 1934 that ended the logging.

Again, laying aside the fact that the fire was over 70 years ago, it would appear that the plan would try to recreate exactly the fire hazard existing then: An open, drier forest, with easy access and a fuel burden of wood chips, logs, and stumps.

3. There have been three small man-made fires in recent years, which were readily extinguished.

Yet the solution seems to be to increase the flammability and improve access to the forest. Surely this increases the risk of man-made fires?

The August 16th update letter also mentioned a personal recollection of a 10-engine fire by a resident, but did not offer any corroborating evidence such as Fire Department records or news items. This was also readily extinguished.

4. The forest has the potential to become unhealthy and therefore more vulnerable to fire.

The report of a consultant concludes that the trees in the canopy are healthy. While anti-eucalyptus campaigners have spoken of a life-span of 100 years, the trees are in good health now, and have a potential life of 400-500 years. One part of the report says the forest cannot regenerate itself because the young eucalyptus is competing with blackberry and other undergrowth; another says that young eucalyptus is everywhere to be seen and must be controlled with herbicides. The report also says the forest is vulnerable to pest attacks; but so are all forests. The oaks they would hope to plant instead are currently at risk from Sudden Oak Death. This is scarcely an argument to destroy a healthy forest.

5. Hot dry winds that blow every fall through San Francisco will dry out the forest and make it vulnerable.

Which hot dry winds are we thinking of? This is San Francisco, not Oakland or Sonoma.

6. The application says the other solution considered was clear-cutting, and only objections from the neighbors prevented them. It also speaks of the risk of mudslides following a fire, but avoids the issue of mudslide following its extensive tree-felling. It also begs the question of how flammable the resulting scrub/ grass would be. The headlands of Marin have a much higher fire-risk than Mount Sutro, according to the website they referenced.

7. In the subgrant application pertaining to Edgewood, it mentions the Angel Island fire – without noting that it was a fire of grass and scrub, precisely the vegetation that would follow the tree removal. The Angel Island fire did not burn in the eucalyptus; it stopped at the tree line. It also ignored the difference in microclimates: Angel Island is warmer and dryer than Mt Sutro.

Fog photos taken in the same hour: Sutro, Angel Island

8. The letter of Aug 16, 2009, also makes reference to another Marin coastal fire – presumably the Mt Vision fire, which is referred to in the strange Q&A that UCSF published. That fire, which started in chaparral, also did not involve eucalyptus.

9. The Edgewood strip in particular mainly backs onto a backs up to wide, long UCSF parking lot. The forest in this area is already quite open and forested with large trees, with a dense green undergrowth. It is unclear how this area constitutes any particular fire-hazard.

10. There is no reference to the fact that the forest is close to one of the city’s largest water sources for fire fighting, the Twin Peaks reservoir.

4 Responses to The “Fire Hazard” that Wasn’t

  1. Are we still fighting UCSF about this forest? Are they really interested in developing it and building on it? Seems like what UC does and this “fire” hazard is the exact methodology they would use to clear-cut the Eucs! Save the Forest!

  2. Pingback: USCF, Sutro Stewards, and the fund-raising “Fire Hazard” | Save Mount Sutro Forest

  3. Pingback: Flaws in UCSF’s Sutro DEIR: Public Comments Due 19 March 2013 | Save Mount Sutro Forest

  4. Pingback: SF Fire Department Busts Some Myths – And More “Work” in Sutro Forest? | Save Mount Sutro Forest

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