Controlled dam releases push Green River to Phase 4 flood alert level - severe flooding

February 7, 2020

Summary

The King County Flood Warning Center has issued a Phase 4 flood alert for the Green River with severe flooding possible, following planned releases from a flood-control dam. The Flood Warning Center continues to monitor widespread river flooding in King County after a powerful rainstorm swept across the region earlier this week.

Story

The King County Flood Warning Center issued a Phase 4 flood alert for the Green River at 8 p.m. on Friday, Feb. 7, with severe flooding possible along portions of the river. Rivers across the county continue to be affected by high flows from heavy rain earlier in the week.

As of 8:30 p.m., the Green River at Auburn was flowing at 12,200 cubic feet per second (CFS), slightly higher than the Phase 4 flood alert threshold for the river. At these flows, critical flood control levees can weaken from saturation. Sudden changes in flood conditions are possible – such as rapidly rising water, widespread inundation and road closures.

The Cedar River is also at a Phase 4 flood alert level, with severe and widespread flooding continuing along significant portions of the river, including numerous road closures from water over roadways. As of 8:30 p.m., the Cedar River at Landsburg was flowing at 7,580 CFS, well above the Phase 4 flood alert threshold of 5,000 CFS. 

Flood patrol crews will be in the field overnight in the Green and Cedar river watersheds to inspect levees, observe flooding behavior, and report any issues back to the Flood Warning Center. 

Elsewhere in the county, the Snoqualmie and Tolt rivers are at Phase 3 flood alerts, with flows generally falling along most of those rivers’ lengths, but road closures and other impacts from high flows are expected to persist. The White River is at a Phase 2 flood alert level, with potentially only minor flooding occurring in low-lying areas.

The Flood Warning Center opened at 5:30 p.m. on Wednesday, Feb. 5, when heavy rainfall brought several rivers up to a minor flood alert level. The 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.

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.