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Tolt River Flooding Information

USGS gage data, map, alert phases, and recent high flows

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New: Click on a gage name for graph and additional data.

USGS Gage Name

Time, Date

Stage
(feet)

Flow
(cfs)

Flow Change
(cfs/hr)

North Fork Tolt River above Yellow Creek 11:30 PM, 12/8/2023 10.30 479 +4
South Fork Tolt River near Carnation 11:30 PM, 12/8/2023 2.04 70 0
Tolt River near Carnation 11:15 PM, 12/8/2023 6.48 1,100 -10

* Gage data currently unavailable.

Notes:

This data was requested from USGS at 12/9/2023 12:25:12 AM.

The next request for USGS data is expected in approximately 5 minutes from when this page was loaded.

cfs = cubic feet per second.
King County provides funding to the United States Geological Survey (USGS) to support the operation and maintenance of river and stream gages and related systems. The term "gage" is defined as an instrument for measuring or testing. USGS uses the term "streamgage" to describe their equipment that obtains estimates of the amount of water flowing in streams and rivers. More information about USGS streamgages
Phase Phase Threshold
Flow at Tolt River near Carnation gage
cfs = cubic feet per second 		Expected Flood Impacts
1 - No flooding typically occurs 2,500 cfs  
2 - Minor Flooding 3,500 cfs Levee on south bank between Snoqualmie Valley Trail Bridge and Highway 203 Bridge may experience seepage.
3 - Moderate Flooding 5,000 cfs Water across Tolt River Rd NE in the vicinity of the former San Souci neighborhood. Increased seepage and potential backyard flooding at levee on south bank between Snoqualmie Valley Trail Bridge and Highway 203 Bridge.
4 - Severe Flooding 8,500 cfs Levees on both banks may overtop between the Snoqualmie Valley Trail Bridge and Highway 203. Flows from seepage at the levee on the south bank between Snoqualmie Valley Trail Bridge and Highway 203 Bridge may cross NE 32nd St. Changes in channel position may occur between the upstream portion of Tolt River Rd NE/361st Avenue NE and the eastern boundary of Carnation.
Tolt River gages map
Recent High Flow Data:
Tolt River near Carnation
December 8, 2015 5,080 cfs*
January 5, 2015 9,340 cfs
January 8, 2009 13,800 cfs
November 12, 2008 11,800 cfs
November 6, 2006 10,500 cfs
October, 2003 11,100 cfs
December, 1999 11,800 cfs
February, 1996 10,300 cfs
November, 1995 11,400 cfs
November, 1990 11,200 cfs

*provisional data

The National Weather Service also provides access to provisional gage data:

Tolt River near Carnation (external link)

Other Flood-related Information

» Historical flood photos
» Return to the The Flood Warning System Page
» Return to King County Flooding Services
» See other Snoqualmie Basin Topics