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Tonsina River at the Richardson Hwy near Tonsina

Highest listed crest 14.57 ftFlood stage 12.5 ft32 crests since 1984

The Tonsina River at the Richardson Hwy near Tonsina crested above flood stage 9 times among the 32 crests the National Weather Service lists from 1984 to 2021. The highest, 14.57 ft on October 11, 2006, was moderate flooding, 2.07 feet above flood stage.

The gauge

Highest listed crest
14.57 ft
October 11, 2006
Flood stage
12.5 ft
No major stage set
Crests at major
0
9 above flood stage
Most recent flood crest
October 11, 2006
14.57 ft, moderate flooding
Identifiers
NWS TONA2
No USGS station

Flood stages

The thresholds the National Weather Service uses for this gauge today, and how many listed crests reached each.

Flood categories, Tonsina River at the Richardson Hwy near Tonsina
Action stage11.514Jun 25, 2012The level at which the NWS or its partners begin to take action
Flood stage (minor)12.54Jun 18, 1994Minimal or no property damage, but possibly some public threat
Moderate flood stage13.05Oct 11, 2006Some inundation of structures and roads near the stream

Every listed crest

32 crests from 1984 to 2021. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Tonsina River at the Richardson Hwy near Tonsina, 1984 to 2021 101112131415ft Flood stage 12.5 ft Jun 25, 1984: 12.16 ft, action stageJul 4, 1985: 12.60 ft, minor floodingJul 7, 1986: 12.40 ft, action stageJul 7, 1987: 12.26 ft, action stageJul 7, 1988: 12.75 ft, minor floodingJul 3, 1989: 11.95 ft, action stageJun 8, 1990: 12.45 ft, action stageJun 23, 1991: 12.22 ft, action stageJul 5, 1992: 12.81 ft, minor floodingJun 5, 1993: 12.18 ft, action stageJun 18, 1994: 12.50 ft, minor floodingSep 22, 1995: 13.00 ft, moderate flooding; 7,000 cubic feet per secondJun 27, 1996: 11.25 ft, below flood stageAug 14, 1997: 12.05 ft, action stageJun 9, 1998: 13.00 ft, moderate floodingJun 19, 1999: 12.26 ft, action stageJun 30, 2000: 13.44 ft, moderate floodingJun 25, 2001: 13.23 ft, moderate floodingJun 25, 2002: 11.93 ft, action stageJun 16, 2003: 11.54 ft, action stageJul 9, 2004: 11.69 ft, action stageJun 20, 2005: 12.17 ft, action stageOct 11, 2006: 14.57 ft, moderate floodingAug 12, 2007: 11.07 ft, below flood stageJun 22, 2008: 11.00 ft, below flood stageJun 8, 2009: 10.59 ft, below flood stageJun 4, 2010: 10.35 ft, below flood stageJun 5, 2011: 10.88 ft, below flood stageJun 25, 2012: 12.15 ft, action stageJun 21, 2016: 10.59 ft, below flood stageJun 12, 2017: 10.27 ft, below flood stageJun 21, 2021: 10.50 ft, below flood stage Highest, 14.57 ft, Oct 11, 2006 1990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Tonsina River at the Richardson Hwy near Tonsina 1980s: 2 1990s: 4 4 2000s: 3 2010s: 0 2020s: 0 1980s1990s2000s2010s2020s
  1. These are the crests the local National Weather Service office lists for the gauge: the highest on record and recent crests. Lesser floods between them may be missing, so counts by decade are a floor.
  2. Categories use today's flood stages. Levees, dams and channel changes since a crest can make old and new stages not directly comparable.

Highest crests

Highest listed crests, Tonsina River at the Richardson Hwy near Tonsina
1Oct 11, 200614.57+2.07Moderate—
2Jun 30, 200013.44+0.94Moderate—
3Jun 25, 200113.23+0.73Moderate—
4Sep 22, 199513.00+0.50Moderate7,000
5Jun 9, 199813.00+0.50Moderate—
6Jul 5, 199212.81+0.31Minor—
7Jul 7, 198812.75+0.25Minor—
8Jul 4, 198512.60+0.10Minor—
9Jun 18, 199412.500.00Minor—
10Jun 8, 199012.45−0.05Action—
11Jul 7, 198612.40−0.10Action—
12Jul 7, 198712.26−0.24Action—
13Jun 19, 199912.26−0.24Action—
14Jun 23, 199112.22−0.28Action—
15Jun 5, 199312.18−0.32Action—
16Jun 20, 200512.17−0.33Action—
17Jun 25, 198412.16−0.34Action—
18Jun 25, 201212.15−0.35Action—
19Aug 14, 199712.05−0.45Action—
20Jul 3, 198911.95−0.55Action—
21Jun 25, 200211.93−0.57Action—
22Jul 9, 200411.69−0.81Action—
23Jun 16, 200311.54−0.96Action—
24Jun 27, 199611.25−1.25Below flood stage—
25Aug 12, 200711.07−1.43Below flood stage—
26Jun 22, 200811.00−1.50Below flood stage—
27Jun 5, 201110.88−1.62Below flood stage—
28Jun 8, 200910.59−1.91Below flood stage—
29Jun 21, 201610.59−1.91Below flood stage—
30Jun 21, 202110.50−2.00Below flood stage—
31Jun 4, 201010.35−2.15Below flood stage—
32Jun 12, 201710.27−2.23Below flood stage—

Other gauges in Copper River Census Area

Flood gauges in Copper River Census Area
Sourdough11.016.03 ft, May 7, 19760
the Richardson Highway near Gulkana10.018.45 ft, May 11, 19860
Glenn Hwy10.512.30 ft, Jun 9, 20120
Glennallen31.041.77 ft, May 31, 20082
McCarthy1,350.01,353.71 ft, Jul 29, 19940

Copper River Census Area: every hazard · River floods across the country · Alaska

NOAA National Water Prediction Service, gauge TONA2, retrieved October 30, 2026. Stages in feet on the gauge's own datum, not elevation. Crests are as the National Weather Service lists them; preliminary values may be revised.