Did you know that most landslides occur between the months of November and March? The threat of landslides will continue to rise as rainfall continues to increase and when snow melts during the winter months.
Most landslides are caused by water (e.g. rainfall, uncontrolled stormwater) or human activity that increases the weight at the top of the slope or reduces the stability at the bottom of the slope. With 20,000 Seattle properties (mostly residential) in landslide-prone areas, Seattle’s Department of Construction and Inspections (SDCI) encourages property owners to take preventive measures to protect themselves from landslides by:
- Checking downspouts; making sure they are functioning/routed to a safe location
- Maintaining drainage systems by clearing away leaves and debris
- Inspecting sloped areas for indications of soil movement and erosion
- Shutting off irrigation systems and inspecting them seasonally
- Keeping fill and yard waste off slopes
- Knowing when to seek professional help for hillside projects
Visit our Emergency Management website to understand if you’re at risk and how to be prepared. Helpful tools include:
- Landslide tutorial
- Interactive GIS Map
- Landslide Prone Area Map
- Do’s & Don’ts
If a landslide damages your property and you have an immediate concern for your safety, leave the premises and call 9-1-1. Seattle property owners with structures that may be affected or endangered by a landslide should also contact SDCI at (206) 615-0808 so that a building inspector can respond and perform an initial assessment of the structure.
Visit the USGS website to view the current conditions of the USGS rainfall threshold for landslides.
Early next year we will be providing presentations on landslide awareness during our annual Seattle Home Fair. More information will be shared in the coming months.