The sixth in our series of responses to UCSF’s July 9th letter.
This is about potential landslides. We’ve included two maps from the FEMA application which clearly indicate this needs discussion.
The letter asks, “Will the projects cause landslides that will put roads and houses at risk?”
It goes on to say, “No. The remaining vegetation will help infiltrate rainfall. On slopes over 30%, vegetation removal will be done selectively and by hand with this in mind. No private homes are downslope from either of the demonstration areas.”
Really? Downslope from the South Ridge, just across the street, are the private homes on Christopher and on Crestmont .
Instead of the existing trees and thick bush, the “remaining vegetation” – which could be as little as 10% of what’s there now – plus some new grass and wildflowers are supposed to consolidate the slope above our homes. Twin Peaks and Forest Knolls are proof that they don’t do so well at it.
We accept the project supporters here don’t expect landslides. Neither did whoever stripped vegetation from the nearby slope (Warren Drive) that lay under a blue tarp for months; or the people who built the Forest Knolls home that slid down the mountain. (See: Forest Knolls home destroyed in landslide-1979) Nor did whoever did the landscaping that results in rockslides on Twin Peaks every rainy season.
The fact is, this mountain is vulnerable to landslides as the map above shows (it’s produced by Consulting Engineers and is part of the FEMA application). In fact, as the next map shows, there have actually *been* landslides in the past in both sites. (Look for the double arrows.) And there’s a map of landslide risk prepared by state geologists (with FEMA funding) indicating most of the mountain is a landslip zone.
So, the obvious question follows: Rather than this destructive, controversial project, “Were other options considered?”
This is what the letter said: “UCSF does not consider alternatives such as clear cutting and controlled burning to be acceptable. The overall concept of using a mixture of livestock grazing, mechanical equipment, hand labor and limited herbicides appears to be most effective.”
Clear-cutting? Controlled burning? We can see why those wouldn’t be good options. Neither, for instance, would pouring concrete over the hillside (which Hong Kong has actually done to stabilize steep slopes). Or leveling the mountain.
Instead of all these drastic and potentially dangerous choices, the best option would be: First, do no harm.
We already have a stable densely-vegetated slope that isn’t covered in thousands of applications of Roundup herbicide. If we strip it off 90% of its vegetation and it lands up in someone’s garage, it won’t console them much to know that it was unexpected.
At a later date, we will make suggestions about caring for this forest which we all love. [ETA: We did.] Except for those who can’t stand eucalyptus and blackberry, of course.