By Steven Schauer, Deputy Executive Director

This blog post was originally scheduled to be our 2025 Year-End Review; a look back at the progress, partnerships, and investments made over the past year to reduce flood risk across King County. However, with widespread and ongoing flooding currently impacting communities throughout King County, we’ve made the decision to pause that reflection.

The 2025 Year-End Review will now be published on December 30.

Today’s post instead focuses on what is happening right now:

• How King County defines flood phases, and
• What flooding looks like across our rivers, by comparing normal conditions to the current flood event.

Our priority during active flood events is clear communication, public safety, and supporting coordination efforts across jurisdictions as communities respond and recover.

Understanding Flood Phases in King County

King County uses flood phases to reflect river flood conditions. The higher the phase, the more water flows in our rivers, and the greater the likelihood of flooding. These phases are based on historical flood conditions unique to each river basin, helping emergency managers, public agencies, and residents understand the severity of an event.

Flood Phases Explained

• Flood Phase 0 – No flooding expected
  Rivers are within normal ranges.
• Flood Phase 1 – Be on alert
  Conditions are being closely monitored, and preparations begin for a possible flood event.
• Flood Phase 2 – Minor flooding expected
  Low-lying areas may flood, and impacts begin to occur.
• Flood Phase 3 – Moderate flooding expected
  Floodwaters may begin to affect homes, roads, and infrastructure.
• Flood Phase 4 – Severe flooding expected
  Significant flooding with potentially threatening impacts to life, property, and critical infrastructure.

During the current event, multiple river basins across King County have reached high flood phases, underscoring the seriousness of this situation.

A Comparison of Rivers in Different Flood Phases

The images below show rivers across King County under non-flood conditions, when water remains within its banks and ecosystems function as expected. These are contrasted with images showing the same rivers during the ongoing flood event, when prolonged rainfall has pushed flows well beyond normal levels, impacting nearby communities, farmland, roads, and infrastructure.

These side-by-side comparisons highlight how dramatically river conditions can change during major storm systems and why flood preparedness, early warning, and long-term flood risk reduction remain essential.

Cedar River

Renton Library

Tabor-Crowall

Jeffrey P. Hagedorn Memorial Bridge (looking upstream)

Herzman to Camp Freeman

Riverbend Levee Setback and Floodplain Restoration

Cummins Revetment (Belmondo’s Reach Park)

Near Belmondo Levee

Jan Road Levee Setback

Royal Arch Levee

Green River

Tukwila 205-Ratola Levee

Desimone Levee

Lower Russell Levee Setback

Galli’s-Dykstra Levee

Issaquah Creek

Momb Revetment

Snoqualmie River

Shake Mill Left Bank Revetment

Record Office Revetment

Snoqualmie Falls (upper viewpoint)

NE 80^th St., West Snoqualmie Valley Rd NE (between NE 80^th St & NE 100^th St), & NE 100^th St

Sinnema Quaale Revetment

NE 124^th St. & Duvall Beach

South Fork Skykomish River

Skykomish Bridge (looking upstream)

Skykomish Bridge (looking downstream)

NE Old Cascade Hwy (looking upstream)

NE Old Cascade Hwy (looking downstream)

Baring Bridge (looking upstream)

Baring Bridge (looking downstream)

Tolt River

Snoqualmie Valley Trail bridge (looking upstream & downstream)

White River

HESCOs near 3^rd Ave SE and railroad bridge, HESCOs upstream of Pacific City Park, & HESCOs near 4^th Ave SE & Pacific City Park

Other Creeks and Rivers in King County

Not all rivers and creeks in King County have flood phases assigned to them. They are still monitored, nevertheless, and many have flood risk reduction facilities to help protect life, property, and infrastructure. Below are examples of this on the Duwamish and Sammamish rivers.

Duwamish River

S. Elmgrove St. & 12 Ave S and Tattatucid Park

Sammamish River

Marymoor Park

Wilmot Gateway Park

The Park at Bothell Landing

Kenmore 68^th Avenue Boat Launch

Looking Ahead

Once floodwater recedes and response efforts transition into recovery, the King County Flood Control District will publish a Flood Event Report. That report will provide:

• Data on river levels and flood phases
• Impacts across King County
• An overview of response actions

In the meantime, we remain focused on supporting communities during this devastating flood event and sharing timely, accurate information as conditions evolve.

Thank you for your patience as we prioritize safety, response, and recovery. Please continue to be flood ready and stay safe by caring for yourself, family, friends, neighbors, and community members.