Snoqualmie River in phase 3 flood alert, road closures possible

Heavy rainfall over the last 24 hours has pushed the Snoqualmie River into a phase 3 flood level.

By Conor Wilson • December 5, 2023 11:45 am
The Snoqualmie River viewed from the State Route 202 bridge in Fall City on Dec. 5. Photos William Shaw/ Valley Record.
The Snoqualmie River viewed from the State Route 202 bridge in Fall City on Dec. 5. Photos William Shaw/ Valley Record.

King County closed it Flood Warning Center at 10 a.m. Wednesday, as river levels across the county began to recede. The Snoqualmie River is still in a phase 2 flood alert, as of 11 a.m. Wednesday, but flows have declined significantly since yesterday’s peak flows. The Tolt River is no longer under a flood alert.

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Heavy rainfall over the last 24 hours has pushed the Snoqualmie River into a phase 3 flood alert, the King County Department of Parks and Natural Resources announced early Tuesday morning.

At this level, flooding is expected across the entire Snoqualmie Valley and could cover some low-lying areas. Fall City-Carnation Road, portions of West Snoqualmie River Road Northeast Tolt Hill Road and Novelty Flats Road, are among those at risk, DNRP said in a news release.

As of 8 a.m. Tuesday, the sum of Snoqualmie’s three forks were recorded at 20,670 cubic feet per second, above the 20,000 cfs threshold required for phase 3. Flows are forecasted to peak Tuesday evening and decline steadily through Thursday

Meanwhile, the Tolt River approached phase 3 early Tuesday, but remains in phase 2 as of press time. Minor flooding, including at the Snoqualmie Valley Trail Bridge and State Route 203 Bridge, is possible.

According to real time data from King County, The Tolt near Carnation is running at just over 4,000 cfs as of 11 a.m Tuesday. That is roughly 1,000 cfs below a phase 3 alert.

King County opened its Flood Warning Center around 2 a.m. Tuesday to monitor flooding on both the Snoqualmie and Tolt Rivers following a stretch of heavy rainfall from an atmospheric river event.

During the duration of the flood event, the warning center can be reached at 206-296-8200 or 1-800-945-9263 for the latest information on current conditions.

Pass Conditions

Snoqualmie Pass saw its first big snowstorm of the year over the weekend. I-90 and the pass received 26 inches of snow, the Washington State Department of Transportation wrote in a post Monday.

The pass was open with no driving restrictions as of press time. Real times updates on traffic condition can be found online: here.

Snoqualmie Falls during a flood event on Dec. 5.

Snoqualmie Falls during a flood event on Dec. 5.