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Portneuf River at Topaz

Highest listed crest 6.00 ftFlood stage 4.0 ft28 crests since 1957

The Portneuf River at Topaz crested above flood stage 15 times among the 28 crests the National Weather Service lists from 1957 to 2022. The highest, 6.00 ft on December 23, 1964, was minor flooding, 1.98 feet above flood stage.

The gauge

Highest listed crest
6.00 ft
December 23, 1964; 1,740 cubic feet per second
Flood stage
4.0 ft
No major stage set
Crests at major
0
15 above flood stage
Most recent flood crest
March 23, 2018
4.92 ft, minor flooding
Location
Bannock County
Idaho

Flood stages

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

Flood categories, Portneuf River at Topaz
Action stage3.55Jun 2, 2019The level at which the NWS or its partners begin to take action
Flood stage (minor)4.015Mar 23, 2018Minimal or no property damage, but possibly some public threat

Every listed crest

28 crests from 1957 to 2022. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Portneuf River at Topaz, 1957 to 2022 23456ft Flood stage 4.0 ft Feb 25, 1957: 5.71 ft, minor flooding; 1,040 cubic feet per secondDec 23, 1964: 6.00 ft, minor flooding; 1,740 cubic feet per secondJan 22, 1969: 5.56 ft, minor flooding; 1,110 cubic feet per secondMay 14, 1971: 5.32 ft, minor flooding; 975 cubic feet per secondApr 10, 1976: 5.27 ft, minor flooding; 1,030 cubic feet per secondFeb 20, 1980: 5.59 ft, minor flooding; 1,150 cubic feet per secondMay 31, 1983: 5.20 ft, minor flooding; 1,030 cubic feet per secondMay 21, 1984: 5.42 ft, minor flooding; 1,350 cubic feet per secondMay 18, 1996: 5.39 ft, minor flooding; 1,170 cubic feet per secondMay 18, 1997: 5.24 ft, minor flooding; 1,080 cubic feet per secondMay 17, 2005: 3.48 ft, below flood stage; 329 cubic feet per secondMay 2, 2006: 5.00 ft, minor flooding; 882 cubic feet per secondFeb 11, 2007: 4.04 ft, minor flooding; 502 cubic feet per secondApr 15, 2008: 3.25 ft, below flood stage; 264 cubic feet per secondJun 12, 2009: 3.83 ft, action stage; 426 cubic feet per secondJun 8, 2010: 3.89 ft, action stage; 398 cubic feet per secondMay 15, 2011: 4.83 ft, minor flooding; 841 cubic feet per secondJan 21, 2012: 3.75 ft, action stage; 630 cubic feet per secondMar 21, 2013: 2.79 ft, below flood stage; 198 cubic feet per secondFeb 15, 2014: 3.55 ft, action stage; 487 cubic feet per secondMay 16, 2015: 2.92 ft, below flood stage; 206 cubic feet per secondApr 14, 2016: 3.17 ft, below flood stage; 314 cubic feet per secondFeb 22, 2017: 4.51 ft, minor flooding; 888 cubic feet per secondMar 23, 2018: 4.92 ft, minor flooding; 1,150 cubic feet per secondJun 2, 2019: 3.72 ft, action stage; 511 cubic feet per secondMay 3, 2020: 3.44 ft, below flood stage; 399 cubic feet per secondJun 7, 2021: 3.28 ft, below flood stage; 305 cubic feet per secondMay 8, 2022: 3.11 ft, below flood stage; 272 cubic feet per second Highest, 6.00 ft, Dec 23, 1964 1960197019801990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Portneuf River at Topaz 1950s: 1 1960s: 2 1970s: 2 1980s: 3 3 1990s: 2 2000s: 2 2010s: 3 2020s: 0 1950s1960s1970s1980s1990s2000s2010s2020s
  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, Portneuf River at Topaz
1Dec 23, 19646.00+1.98Minor1,740
2Feb 25, 19575.71+1.69Minor1,040
3Feb 20, 19805.59+1.57Minor1,150
4Jan 22, 19695.56+1.54Minor1,110
5May 21, 19845.42+1.40Minor1,350
6May 18, 19965.39+1.37Minor1,170
7May 14, 19715.32+1.30Minor975
8Apr 10, 19765.27+1.25Minor1,030
9May 18, 19975.24+1.22Minor1,080
10May 31, 19835.20+1.18Minor1,030
11May 2, 20065.00+0.98Minor882
12Mar 23, 20184.92+0.90Minor1,150
13May 15, 20114.83+0.81Minor841
14Feb 22, 20174.51+0.49Minor888
15Feb 11, 20074.04+0.02Minor502
16Jun 8, 20103.89−0.13Action398
17Jun 12, 20093.83−0.19Action426
18Jan 21, 20123.75−0.27Action630
19Jun 2, 20193.72−0.30Action511
20Feb 15, 20143.55−0.47Action487
21May 17, 20053.48−0.54Below flood stage329
22May 3, 20203.44−0.58Below flood stage399
23Jun 7, 20213.28−0.74Below flood stage305
24Apr 15, 20083.25−0.77Below flood stage264
25Apr 14, 20163.17−0.85Below flood stage314
26May 8, 20223.11−0.91Below flood stage272
27May 16, 20152.92−1.10Below flood stage206
28Mar 21, 20132.79−1.23Below flood stage198

The worst floods along the Portneuf River

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

May 21, 1984: 5.42 ft here, minor flooding

  • PocatelloID · May 17, 1984 · 13.85 ft · Major · its highest

Gauges on the Portneuf River

In USGS station-number order, which runs downstream within a river basin.

Flood gauges on the Portneuf River
Topaz this gaugeID4.06.00 ft, Dec 23, 19640
PocatelloID8.513.85 ft, May 17, 19843
TyheeID6.26.76 ft, May 6, 19860

Other gauges in Bannock County

Flood gauges in Bannock County
McCammon5.613.85 ft, May 17, 19840
Pocatello8.513.85 ft, May 17, 19843
Tyhee6.26.76 ft, May 6, 19860

Bannock County: every hazard · River floods across the country · Idaho

NOAA National Water Prediction Service, gauge TOPI1, 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.