King County: Phase 3 flood alerts for Cedar River, Issaquah Creek; Phase 2 for Snoqualmie River

February 5, 2020

Summary

Pushed higher by heavy rain across eastern King County, the Cedar River and Issaquah Creek have reached a Phase 3 flood alert level, while the Snoqualmie River has reached a Phase 2 according to the King County Flood Warning Center, which opened at 5:30 p.m. on Wednesday, Feb. 5, to monitor conditions.

Story

Heavy rain continues to lift river and stream levels higher across King County late Wednesday night, Feb. 5, and the King County Flood Warning Center has issued Phase 3 flood alerts for the Cedar River and Issaquah Creek, where moderate flooding including road closures are possible; and a Phase 2 flood alert for the Snoqualmie River, where minor flooding could occur in low-lying areas.

As of 11 p.m. on Wednesday, the Cedar River at Landsburg was flowing at 4,270 cubic feet per second (CFS), slightly higher than the Phase 3 flood alert threshold of 4,200 CFS. 

At Phase 3 flood alert levels, roads near the Cedar River could overtop and close, including roads that provide access to neighborhoods can become trapped and require evacuation. Roads that could potentially overtop include:

- Southeast Jones Road near 156th Place Southeast;
- State Route 169 near the intersection of Cedar Grove Road Southeast;
- Southeast 184th Street;
- Byers Road Southeast;
- 216th Avenue Southeast;
- Southeast 193rd Street;
- Southeast 207th Street;
- Lower Dorre Don Way Southeast and Dorre Don Way Southeast; and
- Southeast 238th Street.

The City of Issaquah is responding to significant widespread flooding along Issaquah Creek, which is at a Phase 3 flood alert level. Additional information is available on the City of Issaquah’s Flood Warning System website.

The Green and White rivers remain at Phase 2 flood alert thresholds, with minor flooding possible in localized areas.

As of 10:45 p.m., the Green River near Auburn was flowing at 8,610 cubic feet per second (CFS), well above the Phase 2 flood alert threshold of 7,000 CFS and approaching the Phase 3 threshold of 9,000 CFS.  At these flows, flooding could occur in low-lying areas upstream of Auburn.

On the White River, flows from Mud Mountain Dam are set at 6,000 CFS, which is 1,000 CFS higher than the Phase 2 flood alert threshold for that river. At these flows, overbank flooding could occur in the vicinity of the A Street Bridge in Auburn, and near Government Canal and Butte Avenue in Pacific. High water could also be expected along the temporary flood protection barriers in Pacific.

The Flood Warning Center opened at 5:30 p.m. on Wednesday, Feb. 5, as several rivers that were still running high following last week’s widespread flood event began to rise with fresh rainfall.

The Flood Warning Center will remain open as long as flood conditions persist. Employees will monitor stream gauges and weather reports and will provide updated information on river conditions as necessary. Real-time river level information is available online at kingcounty.gov/flood.

During river flooding events, King County serves as a clearinghouse for information on flood conditions, operating a recorded message center with continuous updates of river gauge readings and flood phases and other related information. Reach the Flood Warning Center at 206-296-8200 or 1-800-945-9263. Interpreter assistance in multiple languages is available.

King County offers everyone free access to KC Flood Alerts, an automated system that allows subscribers to receive customized email, text or voicemail alerts of potential flooding for any or all of King County’s seven major river systems.

Find the KC Flood Alerts link at kingcounty.gov/flood. This website is a valuable preparedness resource, with all of the latest information about river levels and road conditions, plus weather reports and other critical links.

Questions or assistance with flooding on smaller streams or urban drainage problems can be called in to 206-477-4811 during business hours, or 206-477-8100 after hours or on weekends.

Problems on County maintained roads can be reported by calling 206-477-8100 or 1-800-KC-ROADS.

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The King County Flood Control District is a special purpose government created to provide funding and policy oversight for flood protection projects and programs in King County. The Flood Control District’s Board is composed of the members of the King County Council. The Water and Land Resources Division of the King County Department of Natural Resources and Parks develops and implements the approved flood protection projects and programs. Information is available at kingcountyfloodcontrol.org.