Landslide Risk SW Washington (Longview, Oso: inspector, subdivisions, to live)

[WestGuest]

Im told my favorite building site in Skamokawa has some risk of landslide-- its near the bottom of a hill that goes up 600 ft. Id rather it was not so steep ( 180- 600 in about 850 ft) and hope for a landslide before I build to flatten it out a bit.


It has lots of young Douglas Firs and they should anchor the ground somewhat. Great views of the Columbia River.


If all other things are equal is it better to build higher up on the hill? More expensive for a road but better views.


I hear hilltops in that area are really cold and windy in winter and folks dont want to live up there.

[blau808]

Originally Posted by WestGuest

Im told my favorite building site in Skamokawa has some risk of landslide-- its near the bottom of a hill that goes up 600 ft. Id rather it was not so steep ( 180- 600 in about 850 ft) and hope for a landslide before I build to flatten it out a bit.


It has lots of young Douglas Firs and they should anchor the ground somewhat. Great views of the Columbia River.


If all other things are equal is it better to build higher up on the hill? More expensive for a road but better views.


I hear hilltops in that area are really cold and windy in winter and folks dont want to live up there.

I'm not so sure you want to be basing these types of decisions on random people from an Internet forum.

These questions would better be suited by a land surveyor or inspector with professional expertise.

[mayfair]

Originally Posted by blau808

I'm not so sure you want to be basing these types of decisions on random people from an Internet forum.

These questions would better be suited by a land surveyor or inspector with professional expertise.

I agree! Pay for a professional to check out the individual property. After what happened at Oso, landslide risk should be taken seriously.

[Diana Holbrook]

Where the 'best' spot to build is on a property is so property specific, there's not just one rule. I love our spot on the top of the hill. Nice view and the bottom part floods so I wouldn't want to be there!

If your hill may slide, it's not any better to be on top or at the bottom. You don't want either one.

Trees add weight and potential energy to a hill, they don't necessarily hold it. Get it looked at by an engineer if you're concerned about it.

[Hemlock140]

Douglas firs and other conifers here are not as good as you might think for preventing slides. Because of the annual rainfall over 8-9 months of the year (98" in Skamokawa!) the roots remain shallow and can easily topple in a wind or with saturated soil.

[StealthRabbit]

There are several slow moving slides, and potential unstable hillsides in saturated and unstable SW WA. Check into the subdivisions lost in kelso and Longview. A builder friend has had inclinometers in many sites in that region for yrs. Get professional consultation.