How to prepare for a long and unpredictable flood season in King County

A "Road Closed Ahead" sign next to a flooded field.
Road closures are common during flood events. It’s important to know alternate routes and never drive through floodwater.

The most common natural disaster in King County is flooding. There have been 29 flood-related federal disaster declarations in the county since 1956, and the science is clear that climate change will increase flood risks to our region. Even minor flooding can cause big disruptions to our infrastructure, closing roads and requiring costly clean-up and repairs to property.

In King County, flooding is most common from October through April. This year, experts predict an El Niño weather pattern. This typically means a warmer, drier winter in our region. However, King County has experienced damaging flood events even in El Niño winters, such as the 2015-2016 flood season. By preparing now, you can help keep you, your family and your property safe.

Bar chart of minor, moderate, and severe flooding on King County rivers where flooding has occurred each flood season since 2013.

What are some threats from flooding?

Floodwaters are powerful and dangerous. Flooding can lead to drowning, trauma, and injury. Most people drown while trying to walk or drive a vehicle through floodwaters. Cleanup after a flood can also be dangerous due to debris, or if storms have knocked out the power.

  • Do not walk, swim, or drive through floodwaters. Turn Around, Don’t Drown.
  • Stay off bridges over fast-moving water.
  • Be prepared to shelter in place or evacuate rapidly.
  • Know how to avoid injury from debris, contaminated water, carbon monoxide poisoning, and damaged buildings and infrastructure.

Whether you rent or own a home or business, experiencing flooding can be upsetting as well as difficult and expensive to clean up. According to the Federal Emergency Management Agency (FEMA), 1 inch of floodwater in a single-story, 1,000-square-foot home can cause close to $11,000 worth of damage. (Check out FEMA’s Cost of Flooding tool to see how much a flood could cost you.)

Did you know FEMA flood insurance policy holders in unincorporated King County receive a 40% premium discount? This is due to the County’s extensive flood risk reduction efforts.

How to prepare for flooding this year

The first step to staying safe during flood season is learning your flood risk. Check your flood risk for where you live, work, go to school, or commute by entering any address at By understanding which areas have the highest risk of flooding you can plan accordingly. Next, take these important actions:

  • Buy flood insurance. It takes 30 days for a policy to take effect, and standard homeowners or renters insurance doesn’t cover flood damage. Renters can buy contents coverage even if the structure is not insured. To better understand how flood insurance can reduce your flood risk, contact floodplain managers Laura Hendrix or Ken Zweig at 206-477-4727. Visit to learn more about flood insurance and how to find an insurance agent.
  • Build an emergency kit. Make sure your kit includes items such as a flashlight with spare batteries, a portable radio, non-perishable food, drinking water, medical necessities, and any necessary items for children or pets.
  • Move hazardous chemicals, such as lawn and gardening herbicides, out of flood-prone areas or dispose of them at one of the County’s household hazardous waste sites. This helps keep chemicals that can harm people and the environment out of floodwater.
  • Clear storm drains and gutters of fallen leaves and other debris to prevent flooding.
  • Before you build or make a repair in a flood-prone area, make sure you have the required permits and are following all applicable land-use regulations. Getting the right permits makes our flood-prone areas less dangerous for people who live and work there.

Learn about these actions and more ways to prepare for flooding.

The top of a red car is barely visible above floodwater from the Snoqualmie River.
An empty, abandoned car in floodwater near the Snoqualmie Valley Trail in 2019.

Stay informed before, during, and after a flood

Through funding provided by the King County Flood Control District, King County developed KC Flood Alerts – a free, automated system offering subscribers access to alerts of potential flooding for seven King County rivers and Issaquah Creek.

Sign up for KC Flood Alerts at, where you can also find information on real-time river levels, road conditions, and weather reports during flood events.

King County also issues flood-related notifications and other emergency information via ALERT King County, a regional emergency information and notification system.

King County activates its Flood Warning Center when river levels rise to designated thresholds, to monitor river gages, weather data, dam operations, and road closures as long as flood conditions persist. Trained County employees take to the field during floods to address safety concerns, such as flooded roadways, and to check on levees and other river facilities.

A person in an orange safety jacket stands next to a car at dusk looking down at a flooded river.
Flood Patrol staff may be dispatched day or night, seven days a week when activated.

When the Flood Warning Center is open, residents can directly contact King County staff 24 hours a day with their flooding concerns and questions by calling 206-296-8200 or 1-800-945-9263.
For assistance with, or questions about, flooding on smaller streams or drainage problems in urban areas, call 206-477-4811 during business hours or 206-296-8100 after hours or on weekends.

Get your questions answered

Do you have questions about your flood risk, how to sign up for flood alerts, or where to find information about flood insurance? Contact us and we’ll put you in touch with staff who can help.

Email – Send an email to   

Phone – Call the King County River and Floodplain Management Section at 206-477-4727.

Leave a Reply