Flooding
Know your risk. Be prepared. Stay safe.
Flooding is one of the most common and damaging natural hazards in Washington state. Whether you live near a river, along the coast, in a city or in a rural area, understanding your flood risk and taking steps to prepare can help protect you, your family and your property.
Know your risk. Be prepared. Stay safe.
Floods can threaten lives, damage homes and businesses, destroy crops, wash out roads and bridges, disrupt utilities and contaminate drinking water. Flooding can also cause erosion, landslides and debris flows.
According to Washington's 2023 State Enhanced Hazard Mitigation Plan, approximately 2 million people live in identified flood hazard areas, and more than $86 billion in structures are located in mapped flood zones. These estimates likely understate the risk because not all flood-prone areas have been mapped.
Climate change, more intense rainfall, changing snowpack, sea level rise and continued development in flood-prone areas are increasing Washington's flood risk.
When Does Flooding Occur?
Flooding can happen year-round, but the causes vary by season and location.
- Fall and early winter: Heavy rainfall on saturated or frozen ground.
- Winter and early spring: Heavy rainfall combined with melting snowpack.
- Late spring: Mountain snowmelt, particularly in Eastern Washington.
- Summer: Intense thunderstorms that can cause flash flooding, especially in Eastern Washington.
- Year-round: Coastal storms, high tides and localized flooding from overwhelmed drainage systems.
Areas affected by recent wildfires are particularly vulnerable to flash flooding, erosion and debris flows during heavy rainfall. To find out more, visit the Department of Natural Resources web page on debris flows following wildfire.
Get ready before water rises
- Sign up for local emergency alerts, check the National Weather Service forecast, and learn what flood watches and warnings mean. A watch means conditions favor flooding; a warning means flooding is imminent or occurring.
- Plan where you would go and more than one route. Keep essential medications, supplies and important documents accessible. Follow local officials’ directions if they tell you to leave. For ideas on how to prepare, visit our website to Be Two Weeks Ready.
- Review your insurance coverage before a flood threatens. For policy details, including information for renters and businesses, visit the Office of the Insurance Commissioner’s flood insurance guide.
Flood Information and Resources
Flood Forecasts and Alerts
- National Weather Service — Weather forecasts and flood warnings.
- NOAA National Water Prediction Service — River levels and flood forecasts.
Flood Risk and Insurance
- FEMA Flood Map Service Center — Find your property's mapped flood risk.
- Washington Department of Ecology — Floodplain management and flood risk reduction.
- Washington Office of the Insurance Commissioner — Flood insurance information.
