Landslide season is upon us!

As you are no doubt aware, summer sun has now given way to fall clouds and rain in western Washington. Unsurprisingly, this weather transition marks the beginning of landslide season. Landslide events impact many more than just landowners of slide locales; resulting power outages, water supply disruptions, and impassable roads have wide-reaching effects, making it helpful to keep current on the landslide risks in your area.

A test project by DNR and NOAA’s National Weather Service (NWS) is trying a raise awareness of landslide hazards, particularly the ones that occur because of heavy and/or prolonged periods of rain. Our online beta (test) map combines recent rainfall measurements from NWS rain gauges with information about the local soils and slide history. The result is a county-wide risk level rating. The map is not intended to predict landslides at any particular time or location; it only rates the overall risk that one might occur based on the amount of rain that has just fallen.

The map is still in its testing phase, but we have placed it on the DNR website so you can be better informed. The DNR “Ear to the Ground” blog has also recently profiled our landslide hazard map. Take a look and see how your county rates now.

Washington Geological Survey’s Landslide Hazard Forecast Map