By Steven Schauer, Deputy Executive Director
Two separate storm systems in the second week of March 2026 prompted the King County Flood Warning Center to activate twice to monitor minor flooding along the Snoqualmie River.
On March 8 and again on March 12, heavy rainfall across the Cascade foothills caused the combined flows of the Snoqualmie River’s three forks to rise above the Phase 2 flood alert threshold, leading Flood Warning Center staff to monitor river conditions, assess potential impacts to low-lying roads, and provide information to the public and partner agencies.
The Flood Warning Center is funded by the King County Flood Control District and staffed by King County.
March 8 Storm Brings Snoqualmie River Above Phase 2 Threshold
On the afternoon of Sunday, March 8, heavy rainfall and warm temperatures pushed the Snoqualmie River to minor flood levels. At 3:30 p.m., the combined flow of the river’s three forks exceeded the Phase 2 threshold of 12,000 cubic feet per second.
At those flows, minor flooding was possible in low-lying areas, including along Southeast Reinig Road, Meadowbrook Road, Mill Pond Road, Neal Road Southeast, and several other roads in the Snoqualmie Valley.
In response, the King County Flood Warning Center opened remotely to monitor river conditions and coordinate information sharing.
Flood Warning Center Closes as Conditions Improve
The March 8 event remained limited in scope, and widespread flooding was not experienced. As rainfall eased later in the day, river levels in the upper Snoqualmie River Valley began to recede.
The Flood Warning Center closed at 6:30 p.m. after just under five hours of monitoring conditions along the Snoqualmie River.
While drier weather allowed rivers to begin returning to normal flows, staff continued to monitor weather forecasts and stream data closely, especially with additional rain expected later in the week.
Second Storm Prompts Another Activation on March 12
Just four days later, another round of heavy rain brought the Flood Warning Center back into operation.
The center opened at 4:00 a.m. on Thursday, March 12, after the Snoqualmie River rose rapidly overnight. By 6:00 a.m., the combined flow of the river’s three forks had climbed above 14,000 cubic feet per second, again surpassing the Phase 2 flood alert threshold.
As with the March 8 event, minor flooding was possible in low-lying areas, including along Southeast Reinig Road, Meadowbrook Road, Mill Pond Road, Neal Road Southeast, and nearby roads.
Brief Activation Reflects Improving River Conditions
Although additional rainfall was forecast across western Washington in the days ahead, widespread river flooding was not expected from the March 12 storm.
As rainfall eased and flows began receding in the upper Snoqualmie River basin, the Flood Warning Center closed at 8:30 a.m. after a brief activation.
At the time of closure, no other local rivers were forecast to reach flood phase in the immediate future, though the Tolt River was expected to come close to Phase 2 the following Monday.
Preparedness and Monitoring Remain Essential
These two March activations underscore how quickly river conditions can change during periods of heavy rainfall, warm temperatures, and fluctuating snow levels in the mountains.
During flood event operations, the Flood Warning Center is staffed 24 hours a day, seven days a week during flood events and serves as a central source of information for the public and for agencies working to protect public safety.
The King County Flood Control District also offers free access to KC Flood Alerts, an automated alert system operated by King County, as service provider to the King County Flood Control District. KC Flood Alerts provide customized notifications for major river systems throughout the county. Subscribers can receive flood alerts by email, text message, or voicemail, helping them stay informed when river levels begin to rise.
For more information and to sign up for alerts, visit the King County Flood Control District’s Be Flood Ready resource page.