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Gulkana River at Sourdough

Highest listed crest 16.03 ftFlood stage 11.0 ft33 crests since 1973

The Gulkana River at Sourdough crested above flood stage 5 times among the 33 crests the National Weather Service lists from 1973 to 2020. The highest, 16.03 ft on May 7, 1976, was minor flooding, 5.03 feet above flood stage.

The gauge

Highest listed crest
16.03 ft
May 7, 1976
Flood stage
11.0 ft
No major stage set
Crests at major
0
5 above flood stage
Most recent flood crest
May 30, 2013
14.62 ft, minor flooding
Identifiers
NWS GRSA2
USGS 15200280; out of service

Flood stages

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

Flood categories, Gulkana River at Sourdough
Action stage9.512Jun 24, 2020The level at which the NWS or its partners begin to take action
Flood stage (minor)11.05May 30, 2013Minimal or no property damage, but possibly some public threat

Every listed crest

33 crests from 1973 to 2020. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Gulkana River at Sourdough, 1973 to 2020 681012141618ft Flood stage 11.0 ft May 16, 1973: 9.92 ft, action stage; 8,840 cubic feet per secondMay 25, 1974: 8.86 ft, below flood stage; 6,750 cubic feet per secondJun 4, 1975: 9.66 ft, action stage; 8,110 cubic feet per secondMay 7, 1976: 16.03 ft, minor floodingJun 2, 1977: 10.07 ft, action stage; 9,170 cubic feet per secondMay 9, 1978: 9.54 ft, action stage; 7,970 cubic feet per secondMay 4, 1989: 10.88 ft, action stage; 11,500 cubic feet per secondSep 12, 1990: 11.26 ft, minor flooding; 12,700 cubic feet per secondMay 24, 1991: 8.94 ft, below flood stage; 6,710 cubic feet per secondJun 3, 1992: 10.08 ft, action stage; 9,420 cubic feet per secondMay 4, 1993: 8.69 ft, below flood stage; 6,170 cubic feet per secondJun 10, 1997: 9.36 ft, below flood stage; 7,470 cubic feet per secondAug 10, 1998: 7.28 ft, below flood stage; 3,130 cubic feet per secondMay 17, 1999: 8.48 ft, below flood stage; 5,340 cubic feet per secondJun 8, 2000: 8.33 ft, below flood stage; 4,890 cubic feet per secondMay 25, 2001: 8.43 ft, below flood stage; 5,090 cubic feet per secondAug 22, 2002: 9.41 ft, below flood stage; 7,380 cubic feet per secondMay 10, 2004: 9.50 ft, action stage; 7,600 cubic feet per secondSep 14, 2005: 7.44 ft, below flood stage; 3,270 cubic feet per secondAug 26, 2006: 10.48 ft, action stage; 10,340 cubic feet per secondOct 10, 2006: 12.00 ft, minor flooding; 15,300 cubic feet per secondJul 30, 2008: 8.91 ft, below flood stage; 5,460 cubic feet per secondMay 5, 2009: 14.64 ft, minor flooding; 12,000 cubic feet per secondJul 25, 2010: 8.41 ft, below flood stage; 4,480 cubic feet per secondMay 23, 2011: 8.63 ft, below flood stage; 4,920 cubic feet per secondJun 14, 2012: 10.29 ft, action stage; 8,130 cubic feet per secondMay 30, 2013: 14.62 ft, minor flooding; 19,300 cubic feet per secondMay 11, 2015: 9.58 ft, action stage; 6,630 cubic feet per secondJul 26, 2016: 8.52 ft, below flood stage; 4,560 cubic feet per secondMay 2, 2017: 8.85 ft, below flood stage; 4,600 cubic feet per secondJun 13, 2018: 10.75 ft, action stage; 9,150 cubic feet per secondMay 9, 2019: 8.57 ft, below flood stage; 4,570 cubic feet per secondJun 24, 2020: 10.09 ft, action stage; 7,690 cubic feet per second Highest, 16.03 ft, May 7, 1976 19801990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Gulkana River at Sourdough 1970s: 1 1980s: 0 1990s: 1 2000s: 2 2 2010s: 1 2020s: 0 1970s1980s1990s2000s2010s2020s
  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, Gulkana River at Sourdough
1May 7, 197616.03+5.03Minor—
2May 5, 200914.64+3.64Minor12,000
3May 30, 201314.62+3.62Minor19,300
4Oct 10, 200612.00+1.00Minor15,300
5Sep 12, 199011.26+0.26Minor12,700
6May 4, 198910.88−0.12Action11,500
7Jun 13, 201810.75−0.25Action9,150
8Aug 26, 200610.48−0.52Action10,340
9Jun 14, 201210.29−0.71Action8,130
10Jun 24, 202010.09−0.91Action7,690
11Jun 3, 199210.08−0.92Action9,420
12Jun 2, 197710.07−0.93Action9,170
13May 16, 19739.92−1.08Action8,840
14Jun 4, 19759.66−1.34Action8,110
15May 11, 20159.58−1.42Action6,630
16May 9, 19789.54−1.46Action7,970
17May 10, 20049.50−1.50Action7,600
18Aug 22, 20029.41−1.59Below flood stage7,380
19Jun 10, 19979.36−1.64Below flood stage7,470
20May 24, 19918.94−2.06Below flood stage6,710
21Jul 30, 20088.91−2.09Below flood stage5,460
22May 25, 19748.86−2.14Below flood stage6,750
23May 2, 20178.85−2.15Below flood stage4,600
24May 4, 19938.69−2.31Below flood stage6,170
25May 23, 20118.63−2.37Below flood stage4,920
26May 9, 20198.57−2.43Below flood stage4,570
27Jul 26, 20168.52−2.48Below flood stage4,560
28May 17, 19998.48−2.52Below flood stage5,340
29May 25, 20018.43−2.57Below flood stage5,090
30Jul 25, 20108.41−2.59Below flood stage4,480
31Jun 8, 20008.33−2.67Below flood stage4,890
32Sep 14, 20057.44−3.56Below flood stage3,270
33Aug 10, 19987.28−3.72Below flood stage3,130

The worst floods along the Gulkana River

For this gauge's highest crests, the other gauges on the Gulkana River that crested above flood stage within a week.

May 5, 2009: 14.64 ft here, minor flooding

May 30, 2013: 14.62 ft here, minor flooding

Gauges on the Gulkana River

Flood gauges sharing the river's name, linked within 80 miles of one another.

Flood gauges on the Gulkana River
Sourdough this gaugeAK11.016.03 ft, May 7, 19760
the Richardson Highway near GulkanaAK10.018.45 ft, May 11, 19860

Other gauges in Copper River Census Area

Flood gauges in Copper River Census Area
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
the Richardson Hwy near Tonsina12.514.57 ft, Oct 11, 20060
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 GRSA2, 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.