Snoqualmie River Flooding Information
USGS gage data, map, alert phases, and recent high flows

» Snoqualmie River conditions: hold mouse pointer over a river gage [] on this map or view a table of gage data.
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» Snoqualmie Valley River Conditions for Mobile

USGS Gage Name

Time, Date

Stage
(feet)

Flow
(c.f.s.)

Flow Change
(c.f.s./hr)

North Fork Snoqualmie River (external link)

4:30 AM, 5/16

6.15

2500

-50

Middle Fork Snoqualmie River (external link)

4:45 AM, 5/16

7.58

6140

-40

South Fork Snoqualmie River (external link)

4:15 AM, 5/16

13.17

1570

-20

Sum of the Forks

4:45 AM, 5/16

n/a

10210

-110

Snoqualmie River near Snoqualmie, WA (external link)

4:30 AM, 5/16

10.75

11300

+ 100

Snoqualmie River near Carnation, WA (external link)

4:15 AM, 5/16

50.86

11700

+ 200

Snoqualmie River near Duvall, WA (external link)

4:30 AM, 5/16

32.31

n/a

n/a

Notes:

The next request for USGS data is 14 minutes, 50 seconds from when this page was loaded.

The flood phases of the Snoqualmie River are based on the sum of flow for the North, Middle and South forks. The sum of the Forks as of 4:45 AM on 5/16/2008 is 10210 c.f.s. (cubic feet per second) based on USGS provisional data (external link). The sum of the forks represents the most recent flows available from three independent gages providing the best available flood warning information. If a gage has an older sampling time than others, its most recent measurement is used in calculating the sum of the forks.

King County provides funding to the United States Geological Survey to support the operation and maintenance of river and stream gages and related systems.

Snoqualmie River Flood Phases

Phase Phase Threshhold (sum of the Forks) Description Roads that may overtop and close

1 6000 c.f.s. Internal Alert

2 12000 c.f.s. Lowland flooding Neal Rd, SE Reinig Rd, West Snoqualmie River Rd NE (Walker Rd) Snoqualmie Meadowbrook Rd, Mill Pond Rd.

3 20000 c.f.s. Flooding of varied depths occurs in the entire Snoqualmie Valley Fall City -Carnation Rd, Tolt Hill Rd, Novelty Flats Rd.

4 38000 c.f.s. Some residential areas may experience dangerous high velocities and flooding of homes. Woodinville-Duvall Rd, SR 203 between Duvall and Carnation, Moon Valley Rd, South Fork Rd

Recent High Flow Data
High Flow Event	Sum of the Forks	Snoqualmie River near Snoqualmie	Snoqualmie River at Carnation
November 6-7, 2006 Provisional Data	53,500 c.f.s.	55,000 c.f.s.	70,500 c.f.s.	61.17 ft
January 18-19, 2005	36,330 c.f.s.	37,100 c.f.s.	49,400 c.f.s.	59.08 ft
October 21, 2003	32,700 c.f.s.	29,200 c.f.s.	31,000 c.f.s.	56.83 ft
February, 1996	44,430 c.f.s.	51,700 c.f.s.	61,600 c.f.s.	60.34 ft
November, 1995	49,350 c.f.s.	50,200 c.f.s.	62,400 c.f.s.	60.30 ft
November, 1990	50,100 c.f.s.	78,800 c.f.s.	65,200 c.f.s.	60.70 ft

The U.S. Army Corps of Engineers also provides access to the provisional gage data:

North Fork Snoqualmie River (external link)
Middle Fork Snoqualmie River (external link)
South Fork Snoqualmie River (external link)
Snoqualmie River near Snoqualmie (external link)
Snoqualmie River near Carnation (external link)
Snoqualmie River at Duvall (external link)

Snohomish County Flood Warning Information (external link), 425-388-5060

Snoqualmie River Flooding Information USGS gage data, map, alert phases, and recent high flows

The U.S. Army Corps of Engineers also provides access to the provisional gage data:

More Snoqualmie Valley Flood Documentation

Snoqualmie River Flooding Information
USGS gage data, map, alert phases, and recent high flows