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Iowa River at Marengo

Highest listed crest 21.38 ftFlood stage 15.0 ft81 crests since 1947

The Iowa River at Marengo crested at major flood stage 10 times among the 81 crests the National Weather Service lists from 1947 to 2024. The highest, 21.38 ft on June 12, 2008, was major flooding, 6.38 feet above flood stage. 10 other gauges on the Iowa River crested above flood stage within a week of it, 8 at their own highest listed crest.

The gauge

Highest listed crest
21.38 ft
June 12, 2008; 51,000 cubic feet per second
Flood stage
15.0 ft
Major flooding from 19.0 ft
Crests at major
10
26th of 203 gauges in Iowa
Most recent flood crest
May 26, 2024
18.16 ft, moderate flooding
Location
Iowa County
Iowa

Flood stages

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

Flood categories, Iowa River at Marengo
Action stage13.07Jun 13, 2002The level at which the NWS or its partners begin to take action
Flood stage (minor)15.024Oct 4, 2016Minimal or no property damage, but possibly some public threat
Moderate flood stage17.035May 26, 2024Some inundation of structures and roads near the stream
Major flood stage19.010Sep 6, 2018Extensive inundation of structures and roads

Every listed crest

81 crests from 1947 to 2024. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Iowa River at Marengo, 1947 to 2024 10121416182022ft Flood stage 15.0 ftMajor 19.0 ft Jun 16, 1947: 18.20 ft, moderate flooding; 34,000 cubic feet per secondJun 22, 1957: 14.82 ft, action stage; 7,060 cubic feet per secondSep 4, 1958: 16.34 ft, minor flooding; 11,000 cubic feet per secondMar 24, 1959: 16.92 ft, minor flooding; 15,400 cubic feet per secondJan 14, 1960: 16.89 ft, minor flooding; 14,000 cubic feet per secondMar 31, 1960: 19.21 ft, major flooding; 30,800 cubic feet per secondMay 10, 1960: 16.03 ft, minor flooding; 13,500 cubic feet per secondFeb 18, 1961: 16.80 ft, minor flooding; 6,200 cubic feet per secondMar 8, 1961: 16.32 ft, minor flooding; 11,500 cubic feet per secondMar 25, 1962: 16.83 ft, minor flooding; 15,000 cubic feet per secondMar 15, 1963: 15.10 ft, minor flooding; 7,700 cubic feet per secondJun 23, 1964: 14.08 ft, action stage; 6,040 cubic feet per secondApr 7, 1965: 17.84 ft, moderate flooding; 19,900 cubic feet per secondMar 2, 1966: 16.75 ft, minor floodingJun 17, 1966: 16.48 ft, minor flooding; 11,600 cubic feet per secondJun 10, 1967: 14.62 ft, action stage; 7,720 cubic feet per secondAug 5, 1968: 11.41 ft, below flood stage; 3,730 cubic feet per secondJul 12, 1969: 19.79 ft, major flooding; 28,300 cubic feet per secondMar 2, 1970: 16.87 ft, minor floodingMay 17, 1970: 16.23 ft, minor flooding; 10,700 cubic feet per secondFeb 20, 1971: 18.15 ft, moderate flooding; 14,000 cubic feet per secondFeb 27, 1971: 18.27 ft, moderate flooding; 8,500 cubic feet per secondJun 18, 1972: 17.49 ft, moderate flooding; 12,600 cubic feet per secondApr 16, 1973: 17.73 ft, moderate flooding; 16,600 cubic feet per secondMay 19, 1974: 18.82 ft, moderate flooding; 21,200 cubic feet per secondMar 24, 1975: 18.82 ft, moderate flooding; 22,200 cubic feet per secondApr 24, 1976: 17.91 ft, moderate flooding; 17,700 cubic feet per secondSep 19, 1977: 17.39 ft, moderate flooding; 15,100 cubic feet per secondJul 21, 1978: 17.99 ft, moderate flooding; 13,000 cubic feet per secondMar 19, 1979: 19.40 ft, major flooding; 22,300 cubic feet per secondMar 13, 1980: 18.74 ft, moderate floodingJun 24, 1981: 12.91 ft, below flood stage; 5,030 cubic feet per secondJun 16, 1982: 18.12 ft, moderate flooding; 21,100 cubic feet per secondJul 3, 1983: 18.19 ft, moderate flooding; 21,600 cubic feet per secondJun 18, 1984: 18.17 ft, moderate flooding; 17,200 cubic feet per secondFeb 21, 1985: 17.62 ft, moderate floodingMar 4, 1985: 17.50 ft, moderate flooding; 16,200 cubic feet per secondMar 19, 1986: 16.65 ft, minor flooding; 10,400 cubic feet per secondMay 18, 1986: 16.59 ft, minor flooding; 13,100 cubic feet per secondAug 26, 1987: 15.15 ft, minor flooding; 7,500 cubic feet per secondJan 31, 1988: 13.73 ft, action stage; 4,500 cubic feet per secondMar 11, 1989: 14.97 ft, action stage; 3,260 cubic feet per secondSep 9, 1989: 10.67 ft, below flood stage; 3,310 cubic feet per secondJun 21, 1990: 18.68 ft, moderate flooding; 18,100 cubic feet per secondJun 8, 1991: 18.25 ft, moderate flooding; 16,300 cubic feet per secondJul 26, 1992: 16.90 ft, minor flooding; 12,400 cubic feet per secondJul 12, 1993: 20.26 ft, major flooding; 37,500 cubic feet per secondJul 19, 1993: 20.31 ft, major flooding; 38,000 cubic feet per secondAug 19, 1993: 19.57 ft, major flooding; 30,900 cubic feet per secondMar 7, 1994: 15.36 ft, minor flooding; 8,350 cubic feet per secondApr 28, 1995: 15.86 ft, minor flooding; 9,210 cubic feet per secondMay 10, 1996: 16.35 ft, minor flooding; 10,900 cubic feet per secondFeb 21, 1997: 17.56 ft, moderate flooding; 10,200 cubic feet per secondJun 30, 1998: 18.92 ft, moderate flooding; 19,500 cubic feet per secondJun 17, 1999: 17.09 ft, moderate flooding; 11,600 cubic feet per secondJul 14, 2000: 14.58 ft, action stage; 6,290 cubic feet per secondMar 23, 2001: 16.46 ft, minor flooding; 9,540 cubic feet per secondJun 13, 2002: 13.35 ft, action stage; 5,180 cubic feet per secondMay 15, 2003: 15.83 ft, minor flooding; 8,880 cubic feet per secondMay 31, 2004: 17.97 ft, moderate flooding; 14,600 cubic feet per secondMay 20, 2005: 15.55 ft, minor flooding; 8,130 cubic feet per secondMay 4, 2006: 12.58 ft, below flood stage; 4,580 cubic feet per secondApr 30, 2007: 18.17 ft, moderate flooding; 15,900 cubic feet per secondJun 12, 2008: 21.38 ft, major flooding; 51,000 cubic feet per secondApr 30, 2009: 17.64 ft, moderate flooding; 15,500 cubic feet per secondJul 6, 2010: 17.78 ft, moderate flooding; 16,200 cubic feet per secondJun 11, 2011: 16.27 ft, minor flooding; 9,950 cubic feet per secondApr 16, 2012: 10.65 ft, below flood stage; 3,430 cubic feet per secondMay 31, 2013: 20.36 ft, major flooding; 37,200 cubic feet per secondJul 2, 2014: 19.96 ft, major flooding; 26,800 cubic feet per secondJun 25, 2015: 17.09 ft, moderate flooding; 13,000 cubic feet per secondDec 18, 2015: 18.31 ft, moderate flooding; 19,000 cubic feet per secondOct 4, 2016: 16.90 ft, minor flooding; 12,302 cubic feet per secondJan 20, 2017: 17.95 ft, moderate flooding; 10,000 cubic feet per secondSep 6, 2018: 19.14 ft, major flooding; 20,800 cubic feet per secondOct 10, 2018: 18.76 ft, moderate floodingMar 17, 2019: 18.83 ft, moderate flooding; 18,400 cubic feet per secondMay 29, 2019: 18.44 ft, moderate flooding; 16,000 cubic feet per secondJun 11, 2020: 17.59 ft, moderate flooding; 13,700 cubic feet per secondJun 25, 2020: 17.93 ft, moderate flooding; 14,756 cubic feet per secondMay 26, 2024: 18.16 ft, moderate flooding; 16,623 cubic feet per second Highest, 21.38 ft, Jun 12, 2008 19501960197019801990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Iowa River at Marengo 1940s: 1 1950s: 2 1960s: 11 1970s: 12 12 1980s: 9 1990s: 12 2000s: 7 2010s: 12 2020s: 3 1940s1950s1960s1970s1980s1990s2000s2010s2020s
  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

The 50 highest of 81 listed crests.

Highest listed crests, Iowa River at Marengo
1Jun 12, 200821.38+6.38Major51,000
2May 31, 201320.36+5.36Major37,200
3Jul 19, 199320.31+5.31Major38,000
4Jul 12, 199320.26+5.26Major37,500
5Jul 2, 201419.96+4.96Major26,800
6Jul 12, 196919.79+4.79Major28,300
7Aug 19, 199319.57+4.57Major30,900
8Mar 19, 197919.40+4.40Major22,300
9Mar 31, 196019.21+4.21Major30,800
10Sep 6, 201819.14+4.14Major20,800
11Jun 30, 199818.92+3.92Moderate19,500
12Mar 17, 201918.83+3.83Moderate18,400
13May 19, 197418.82+3.82Moderate21,200
14Mar 24, 197518.82+3.82Moderate22,200
15Oct 10, 201818.76+3.76Moderate—
16Mar 13, 198018.74+3.74Moderate—
17Jun 21, 199018.68+3.68Moderate18,100
18May 29, 201918.44+3.44Moderate16,000
19Dec 18, 201518.31+3.31Moderate19,000
20Feb 27, 197118.27+3.27Moderate8,500
21Jun 8, 199118.25+3.25Moderate16,300
22Jun 16, 194718.20+3.20Moderate34,000
23Jul 3, 198318.19+3.19Moderate21,600
24Jun 18, 198418.17+3.17Moderate17,200
25Apr 30, 200718.17+3.17Moderate15,900
26May 26, 202418.16+3.16Moderate16,623
27Feb 20, 197118.15+3.15Moderate14,000
28Jun 16, 198218.12+3.12Moderate21,100
29Jul 21, 197817.99+2.99Moderate13,000
30May 31, 200417.97+2.97Moderate14,600
31Jan 20, 201717.95+2.95Moderate10,000
32Jun 25, 202017.93+2.93Moderate14,756
33Apr 24, 197617.91+2.91Moderate17,700
34Apr 7, 196517.84+2.84Moderate19,900
35Jul 6, 201017.78+2.78Moderate16,200
36Apr 16, 197317.73+2.73Moderate16,600
37Apr 30, 200917.64+2.64Moderate15,500
38Feb 21, 198517.62+2.62Moderate—
39Jun 11, 202017.59+2.59Moderate13,700
40Feb 21, 199717.56+2.56Moderate10,200
41Mar 4, 198517.50+2.50Moderate16,200
42Jun 18, 197217.49+2.49Moderate12,600
43Sep 19, 197717.39+2.39Moderate15,100
44Jun 17, 199917.09+2.09Moderate11,600
45Jun 25, 201517.09+2.09Moderate13,000
46Mar 24, 195916.92+1.92Minor15,400
47Jul 26, 199216.90+1.90Minor12,400
48Oct 4, 201616.90+1.90Minor12,302
49Jan 14, 196016.89+1.89Minor14,000
50Mar 2, 197016.87+1.87Minor—

The worst floods along the Iowa River

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

June 12, 2008: 21.38 ft here, major flooding

  • Columbus JctIA · Jun 15, 2008 · 32.30 ft · Major · its highest
  • WapelloIA · Jun 14, 2008 · 32.15 ft · Major · its highest
  • Iowa CityIA · Jun 15, 2008 · 31.53 ft · Major · its highest
  • OakvilleIA · Jun 14, 2008 · 23.22 ft · Major · its highest
  • Lone Tree (Tri-County Bridge)IA · Jun 15, 2008 · 23.10 ft · Major · its highest
  • RowanIA · Jun 9, 2008 · 15.89 ft · Moderate · its highest
  • MarshalltownIA · Jun 13, 2008 · 21.79 ft · Minor
  • Tama US 63IA · Jun 13, 2008 · 21.31 ft · Minor
  • Belle PlaineIA · Jun 13, 2008 · 19.86 ft · Minor · its highest
  • Steamboat RockIA · Jun 8, 2008 · 17.86 ft · Minor · its highest

May 31, 2013: 20.36 ft here, major flooding

July 12, 1993: 20.26 ft here, major flooding

Gauges on the Iowa River

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

Flood gauges on the Iowa River
Belle PlaineIA15.019.86 ft, Jun 13, 20080
Columbus JctIA23.032.30 ft, Jun 15, 20083
Iowa CityIA23.531.53 ft, Jun 15, 20082
Marengo this gaugeIA15.021.38 ft, Jun 12, 200810
MarshalltownIA19.022.25 ft, Jul 2, 20140
OakvilleIA11.023.22 ft, Jun 14, 20081
Steamboat RockIA11.017.86 ft, Jun 8, 20080
WapelloIA21.032.15 ft, Jun 14, 20087
Lone Tree (Tri-County Bridge)IA16.023.10 ft, Jun 15, 20083
RowanIA12.515.89 ft, Jun 9, 20080
Tama Hwy E49IA12.515.20 ft, May 28, 20133
Tama US 63IA20.022.31 ft, Apr 28, 20070

Other gauges in Iowa County

Flood gauges in Iowa County
Ladora20.026.61 ft, Jul 1, 20140
Parnell24.030.06 ft, Jul 1, 20140
Belle Plaine15.019.86 ft, Jun 13, 20080

Iowa County: every hazard · River floods across the country · Iowa

NOAA National Water Prediction Service, gauge MROI4, 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.