Identifying Landslide Hazards

In February of 1996, a major storm caused hundreds of landslides in the West Hills of Portland and several years ago a landslide destroyed several homes in SW Portland. Many factors contribute to landslides, including slope steepness, soil strength, and moisture content of the soil. A landslide will occur when several of these factors converge.

Shortly after this incident the state launched a safety initiative that called for landslide hazard maps. I haven’t seen these landslide hazard maps, the reason being these maps were never formally adopted after some city and county officials complained that the maps represented a regulatory headache that might restrict development.

The main culprit of these recent landslides is not just due to improper drainage but the fact that many of these homes should not have been built where they currently are situated in the first place.

Other than having the right insurance in place the best risk management to have in place for the protection of your home would be the following:

 Address drainage problems. Rain and melting snow will stream itself into channels and if you don’t divert this water from your home you will take on the potential for water damage.

 If you build or purchase a home on, above, or below a hillside you take your chances. Make certain that the property site adheres to the state building codes from the setbacks from slopes.

 Don’t live on, above, or below a hillside. Consider the odds for a loss. The three ingredients of landslides are steep slopes, loose soil and water. We live in prime landslide areas.

Landslide Hazard Maps Oregon

To see how your home is rated for landslide risk, go to the Oregon Coastal Atlas and zoom to your property’s location.

Search the Oregon Landslide Information Database to map the landslide risk for your Oregon home. The database is a compilation of landslides in Oregon that have been identified on published maps.

To learn more about landslides visit these resources:

 Landslides In Oregon Fact Sheet

 USGS Landslide Hazard Program for Portland Oregon

 Pudget Sound Landslide Information