Comments on: West Seattle Weather Watch: Alki mudslide closes road

By: WSB

WSB — Mon, 14 Jan 2013 01:07:09 +0000

Didn’t know it wasn’t cleaned up yet – meant to look while in the Alki area today and forgot to ask our photographer. Will ask SDOT tomorrow about its status! – TR

By: Lisa

Lisa — Mon, 14 Jan 2013 00:44:43 +0000

Still wondering when the city plans to clean this up and reopen the road.

WSB – can you find anything out?

By: Ray West

Ray West — Sun, 13 Jan 2013 14:59:52 +0000

Landslides are a natural process, but human interaction has acerbated the problem more than Mother Nature. Trees are very important in stabilizing a hillside, not only the roots, but also the leaf litter from deciduous trees. Dead leaves on the ground create a natural protective layer, repelling rainfall and keeping it from soaking into the soil. When too many trees are cut down for development or someone wants a better view, then the ground becomes saturated with water and mass wasting (landslides) can result.

By: Lisa

Lisa — Thu, 10 Jan 2013 22:07:26 +0000

When will they clear up 55th?

Nothing has changed since yesterday, except the van owner has moved the van. The road is still closed and full of mud with the tree in the middle of the road. To me it actually looks like more mud has slipped down. Are they waiting for the slope to stabilize? When do they think that will be?

I also understand that the city wants to see whether the landowner is responsible for the cleanup or not – so maybe that’s the issue.

Regardless – how many days will the mud and tree sit there before the city deals w/ it?

By: Looks reasonable to me

Looks reasonable to me — Thu, 10 Jan 2013 19:09:28 +0000

Kate – that spot – right next to the goats – has a well-underway construction project down below, with a newish retaining wall above the construction. Peeking over the edge, it looks like quite a bit of bramble was probably removed while they constructed the reatng wall, or maybe later to monitor whether the retaining wall was doing its job.
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Speaking of Jacobsen – the sidewalk has been cleared!!!

By: WSB

WSB — Thu, 10 Jan 2013 18:12:55 +0000

Can’t go look yet but … in the area where the trees were cut recently, just wondering? – TR

By: kate

kate — Thu, 10 Jan 2013 18:10:13 +0000

Hi Happiness- If you’re walking down Jacobsen, towards the water, the slide appears to have happened around the second crosswalk to the left of the guardrail. Earlier this fall I saw goats chewing their way through the bramble in that area too. Let me know what you think next time you walk by.

By: ak

ak — Thu, 10 Jan 2013 13:25:32 +0000

Les-spot on. As someone who grew up on the street, the whole side of the street where the mudslide happened used to be full of blackberry’s. In the summer people would come and pick them to make Jelly or pie. They have been gotten rid of and now look what happened.

By: Marie M

Marie M — Thu, 10 Jan 2013 06:55:00 +0000

Once again, here’s my post about trees and mudslides http://www.whereiamnow.net/2010/02/trees-and-mudslides.html A lot of what we used to believe about plants and mudslides has turned out to be wrong. Trees do not necessarily prevent mudslides. Nor do trees have “taproots” as was believed in the past.

By: Mike D.

Mike D. — Thu, 10 Jan 2013 06:18:50 +0000

Very glad to see Les Treal contributing to this discussion. Keep an open mind as he has years and years of field experience and knowledge.
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My Dad was a Geologist, and would always tell us kids that soils around here are lake layers in a cake, but they don’t stick together very well. Add a lot of weight, as in rainfall, or yes, even trees, and the top layer of the cake goes slip sliding away. Keeping the water out of the slope or controling it’s movement through the slope and decreasing the deadload on the uppermost layer of soil will reduce the chances of the area sliding.

By: WSB

WSB — Thu, 10 Jan 2013 03:46:47 +0000

Rhonda’s site in fact links to a great deep dive into information about West Seattle landslides and landslide risk – I was just going through it. This is the direct link to the WS info:
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http://www.seattle.gov/dpd/landslide/study/part3.asp#11.0

By: mike

mike — Thu, 10 Jan 2013 03:17:06 +0000

Lisa, you may find info on this site useful: http://www.ecy.wa.gov/programs/sea/pubs/93-30/using01.html

My experience is that Himalayan blackberry’s have very little root structure just the “Brain”. Most experts agree that the best retaining is a mix of native trees and shrubs. Western Red cedar is a favorite tree of mine. But its true that slides are part of the natural process.

By: Rhonda Porter

Rhonda Porter — Thu, 10 Jan 2013 03:09:46 +0000

Kate, the city of Seattle has maps available that show of potential slide areas – parts of Jacobson are on that map.

By: Lisa

Lisa — Thu, 10 Jan 2013 02:47:54 +0000

What effect does shrubbery (low plants, unlikely to be caught by wind) rather than big trees have on slopes? To me, it seems logical that to stablilize a slope you’d want something not too tall and heavy, not likely to “tip, ” but with lots of root structure. I know blackerry bushes are a menace in other ways, but that’s why I made that comment.

But this is just my gut speaking. I’m interested to know what the different theories are (unless it will cause a huge angry debate here).

By: r.f.

r.f. — Thu, 10 Jan 2013 01:39:01 +0000

Hey Les,
… deje vu my friend. Anyone that wants to see Les, Bernie and the crews handiwork, should drive by 5940 Beach Dr. S.W. and the residences on either side, they are testament of there skill and expertise. I can tell you from first hand experience, he knows that, of what he speaks, and is highly regarded by those familiar with building difficult sights.
Give our best regards to everyone.

R.& J.