West Seattle briefing: Elevated landslide risk

(click to see larger, citywide version)
That’s part of a city map distributed at a media briefing we attended this morning at Don Armeni (with the steep slide-prone slope of California Way, and North Admiral ridgetop homes, as a backdrop) – red marks the steepest areas, blue marks other potential landslide zones. Reps from Seattle Public Utilities and the Department of Planning and Development warn that last week’s heavy, sustained rain raised the landslide risk – and one more storm (there’s more rain in the forecast) could elevate it further – so they are distributing information on what to look out for, as well as publicizing a workshop you’ll want to attend if your home or business is in a potential slide zone – read on to find out more, and to hear about one of the West Seattle spots that experts watch closely:

That stretch of SW Jacobsen over Beach Drive (just south of Me-Kwa-Mooks) is one of the areas that landslide expert Bill Benzer told reporters he goes back to check on from time to time – so far, the shoring-up work that the city did is holding nicely, he says. Benzer says 86 percent of landslides have some sort of human culpability – so what are some of the things that worsen the risk, a briefing attendee asked?

What else do homeowners need to know? Here’s an important handout the city distributed for us to share: Landslide do’s and don’ts (click that link to get the PDF). Now, the big finish: The city’s landslide-info workshop in West Seattle is coming up December 6th, 10 am-noon, South Seattle Community College. Free!

8 Replies to "West Seattle briefing: Elevated landslide risk"

  • JoB November 10, 2008 (1:45 pm)

    one more reason to be glad i have moved. i can visit the view.. but i no longer have to worry about the landslide risk… and other people’s bad practices that contribute to it.

  • nervous on a hill November 10, 2008 (6:12 pm)

    So what do you do if you live next door to someone who does dump small dead trees, tree limbs, branches, leaves, flower pots and newspapers down his hill?

  • WSB November 10, 2008 (6:36 pm)

    You should be able to file a complaint with DPD (same way someone would complain about plants growing over a sidewalk, junk on a lot, etc.). Have you tried that already?

  • Neighbor November 10, 2008 (8:05 pm)

    Wonder if this will stop clearing and planned building in some of the slide areas noted on the map (Delridge and the infamous Beach Drive)? There’s a fair difference for some folks between knowledge and action…

  • Alia November 11, 2008 (1:36 pm)

    I’m in a red zone. Yeek.

  • slide nulu November 11, 2008 (3:17 pm)

    Concerns about new construction as in “Comment by Neighbor” should be the least of our worries.
    After a stinging round of lawsuits a dozen years ago, the city has made it tougher and tougher to build in these areas.
    The DPD has tightened the code twice in the last three years with additional restrictions coming into effect this week.
    Currently DPD requires extensive surveying, geotechnical analysis, civil engineering, soils tests, water run-off collection and structural engineering that did not exist when the sliding homes were constructed. To build in these areas a costly and time consuming variance was added two years ago. Builders are also required to sign legal documents shouldering all responsibility due to a slide.
    The steep slope house we just completed above Delridge, will reduce threat of slides by actually holding the hillside up with pin piles driven down through the loose slide soils until anchored into the hardrock soil sometimes 20 to 60 feet deep. Our house required 23 four inch diameter pin piles.
    Additionally, we are now required to collect all of the “hard surface runoff”, pipe it into a detention cistern that then trickles the water directly into our storm drains. As a result, all of the rain formerly soaking and loading the hillside is collected and safely removed. Contrast this with existing houses such as “Comment by Neighbor”s whose house is likely “grandfathered” with roof, gutter and driveway draining directly into the hillside. A neighbor to our project complained about having to re-route the french drain someone had installed directly into OUR hillside property from his gutter.
    Some of this is why the city is doing a PR campaign aimed at homeowners almost all of whom live in hillside homes without current safeguards or restrictions. And many of them follow practices they have followed for years:”we have always dumped our grass over the hill”, “Our roof has been draining that way for fifty years. How could it be a problem?”
    Let’s just blame the neighbors, the city or new construction. But we are all responsible.

  • ws4ever November 18, 2008 (4:10 am)

    It’s interesting that the DPD declined to distribute good practices on hillsides information in our neighborhood, as I had similar concerns to Nervous on a Hill. Why is that information not dispensed to avoid problems, rather than wait for neighbors to file a grievance with the DPD when uninformed people do things to harm the hillside? Even when I did file a grievance the DPD fired the inspector who agreed that I had a valid complaint.

  • NIMBY nulu November 18, 2008 (6:20 pm)

    Difficult as it may be to deal with the DPD, their website has info on steep slope dumping. Their CAMS available online and at DPD downtown also address this. King County also has info.
    They also have regular outreach public info meetings.
    If you report the incident the violators will likely be contacted by DPD and instructed about good practices.
    And even if DPD did fire your inspector, at least the violator became aware.

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