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Shell Rock River at Shell Rock

Highest listed crest 21.40 ftFlood stage 12.0 ft73 crests since 1856

The Shell Rock River at Shell Rock crested at major flood stage 2 times among the 73 crests the National Weather Service lists from 1856 to 2025. The highest, 21.40 ft on September 23, 2016, was major flooding, 9.40 feet above flood stage.

The gauge

Highest listed crest
21.40 ft
September 23, 2016; 45,000 cubic feet per second
Flood stage
12.0 ft
Major flooding from 18.0 ft
Crests at major
2
70th of 203 gauges in Iowa
Most recent flood crest
August 1, 2025
13.32 ft, minor flooding
Location
Butler County
Near Waverly (5.8 mi), Cedar Falls (14.9 mi)

Flood stages

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

Flood categories, Shell Rock River at Shell Rock
Action stage10.023Jun 16, 2022The level at which the NWS or its partners begin to take action
Flood stage (minor)12.036Aug 1, 2025Minimal or no property damage, but possibly some public threat
Moderate flood stage16.03Jul 22, 1999Some inundation of structures and roads near the stream
Major flood stage18.02Sep 23, 2016Extensive inundation of structures and roads

Every listed crest

73 crests from 1856 to 2025. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Shell Rock River at Shell Rock, 1856 to 2025 510152025ft Flood stage 12.0 ftMajor 18.0 ft Jan 1, 1856: 17.70 ft, moderate flooding; 45,000 cubic feet per secondJun 22, 1954: 14.00 ft, minor flooding; 21,300 cubic feet per secondJun 5, 1955: 6.27 ft, below flood stage; 2,640 cubic feet per secondApr 2, 1956: 6.50 ft, below flood stage; 2,800 cubic feet per secondMay 31, 1957: 5.74 ft, below flood stage; 2,200 cubic feet per secondJun 4, 1958: 7.99 ft, below flood stage; 1,650 cubic feet per secondMar 27, 1959: 11.03 ft, action stage; 7,630 cubic feet per secondMar 30, 1960: 11.54 ft, action stage; 10,100 cubic feet per secondMar 28, 1961: 16.26 ft, moderate flooding; 33,500 cubic feet per secondMar 30, 1962: 13.64 ft, minor flooding; 16,400 cubic feet per secondMay 11, 1963: 12.70 ft, minor flooding; 13,600 cubic feet per secondSep 10, 1964: 9.70 ft, below flood stage; 2,500 cubic feet per secondApr 7, 1965: 15.09 ft, minor flooding; 24,400 cubic feet per secondFeb 10, 1966: 11.66 ft, action stage; 9,300 cubic feet per secondJun 11, 1967: 10.12 ft, action stage; 3,880 cubic feet per secondJun 27, 1968: 11.08 ft, action stage; 4,920 cubic feet per secondJun 30, 1969: 15.49 ft, minor flooding; 24,500 cubic feet per secondMay 15, 1970: 10.95 ft, action stage; 5,440 cubic feet per secondApr 1, 1971: 13.02 ft, minor flooding; 11,900 cubic feet per secondSep 29, 1972: 11.36 ft, action stage; 7,060 cubic feet per secondMar 12, 1973: 12.37 ft, minor flooding; 10,600 cubic feet per secondJun 10, 1974: 12.92 ft, minor flooding; 13,600 cubic feet per secondApr 29, 1975: 12.36 ft, minor flooding; 12,100 cubic feet per secondMar 13, 1976: 11.52 ft, action stage; 6,790 cubic feet per secondSep 18, 1977: 8.49 ft, below flood stage; 1,220 cubic feet per secondJun 18, 1978: 12.31 ft, minor flooding; 9,320 cubic feet per secondAug 24, 1979: 15.01 ft, minor flooding; 21,100 cubic feet per secondAug 12, 1980: 13.29 ft, minor flooding; 12,900 cubic feet per secondJun 25, 1981: 12.22 ft, minor flooding; 9,810 cubic feet per secondMar 18, 1982: 11.92 ft, action stage; 9,020 cubic feet per secondSep 21, 1983: 12.24 ft, minor flooding; 10,100 cubic feet per secondJun 24, 1984: 12.43 ft, minor flooding; 10,900 cubic feet per secondFeb 22, 1985: 9.71 ft, below flood stage; 4,280 cubic feet per secondMar 20, 1986: 12.62 ft, minor flooding; 11,500 cubic feet per secondOct 13, 1986: 11.08 ft, action stage; 7,410 cubic feet per secondMar 12, 1989: 9.62 ft, below flood stage; 2,340 cubic feet per secondJul 29, 1990: 13.43 ft, minor flooding; 12,800 cubic feet per secondMay 19, 1991: 14.36 ft, minor flooding; 17,100 cubic feet per secondMar 10, 1992: 12.86 ft, minor flooding; 11,600 cubic feet per secondApr 1, 1993: 15.21 ft, minor flooding; 20,800 cubic feet per secondMar 7, 1994: 13.34 ft, minor flooding; 7,900 cubic feet per secondApr 13, 1995: 10.65 ft, action stage; 4,780 cubic feet per secondMar 31, 1996: 9.98 ft, below flood stage; 3,210 cubic feet per secondJun 19, 1996: 10.11 ft, action stageMar 12, 1997: 12.49 ft, minor flooding; 11,200 cubic feet per secondJun 29, 1998: 11.83 ft, action stage; 7,860 cubic feet per secondJul 22, 1999: 16.73 ft, moderate flooding; 27,500 cubic feet per secondJun 15, 2000: 12.61 ft, minor flooding; 11,800 cubic feet per secondApr 13, 2001: 14.12 ft, minor flooding; 19,500 cubic feet per secondAug 7, 2002: 10.69 ft, action stage; 4,970 cubic feet per secondMay 13, 2003: 11.23 ft, action stage; 6,400 cubic feet per secondMay 23, 2004: 15.87 ft, minor flooding; 27,400 cubic feet per secondApr 21, 2005: 11.92 ft, action stage; 7,700 cubic feet per secondApr 4, 2006: 11.51 ft, action stage; 6,610 cubic feet per secondApr 3, 2007: 11.85 ft, action stage; 7,500 cubic feet per secondJun 10, 2008: 20.36 ft, major flooding; 60,400 cubic feet per secondMay 29, 2009: 10.99 ft, action stage; 5,290 cubic feet per secondMar 14, 2010: 13.64 ft, minor flooding; 14,200 cubic feet per secondMar 24, 2011: 12.69 ft, minor flooding; 10,400 cubic feet per secondMay 7, 2012: 10.10 ft, action stage; 3,310 cubic feet per secondJun 14, 2013: 14.95 ft, minor flooding; 20,500 cubic feet per secondJun 21, 2014: 13.82 ft, minor flooding; 15,000 cubic feet per secondJun 24, 2015: 11.15 ft, action stage; 5,700 cubic feet per secondSep 23, 2016: 21.40 ft, major flooding; 45,000 cubic feet per secondOct 1, 2016: 12.01 ft, minor flooding; 8,160 cubic feet per secondJun 11, 2018: 15.45 ft, minor flooding; 22,400 cubic feet per secondMar 16, 2019: 14.48 ft, minor flooding; 17,600 cubic feet per secondJun 23, 2020: 12.63 ft, minor flooding; 11,800 cubic feet per secondAug 29, 2021: 11.08 ft, action stage; 6,130 cubic feet per secondJun 16, 2022: 11.26 ft, action stage; 6,300 cubic feet per secondMar 1, 2023: 13.13 ft, minor flooding; 12,900 cubic feet per secondJun 24, 2024: 12.94 ft, minor floodingAug 1, 2025: 13.32 ft, minor flooding; 13,000 cubic feet per second Highest, 21.40 ft, Sep 23, 2016 1880192019602000

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Shell Rock River at Shell Rock 1850s: 1 1860s: 0 1870s: 0 1880s: 0 1890s: 0 1900s: 0 1910s: 0 1920s: 0 1930s: 0 1940s: 0 1950s: 1 1960s: 5 1970s: 6 1980s: 5 1990s: 7 2000s: 4 2010s: 8 8 2020s: 4 1850s1870s1890s1910s1930s1950s1970s1990s2010s
  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 73 listed crests.

Highest listed crests, Shell Rock River at Shell Rock
1Sep 23, 201621.40+9.40Major45,000
2Jun 10, 200820.36+8.36Major60,400
3Jan 1, 185617.70+5.70Moderate45,000
4Jul 22, 199916.73+4.73Moderate27,500
5Mar 28, 196116.26+4.26Moderate33,500
6May 23, 200415.87+3.87Minor27,400
7Jun 30, 196915.49+3.49Minor24,500
8Jun 11, 201815.45+3.45Minor22,400
9Apr 1, 199315.21+3.21Minor20,800
10Apr 7, 196515.09+3.09Minor24,400
11Aug 24, 197915.01+3.01Minor21,100
12Jun 14, 201314.95+2.95Minor20,500
13Mar 16, 201914.48+2.48Minor17,600
14May 19, 199114.36+2.36Minor17,100
15Apr 13, 200114.12+2.12Minor19,500
16Jun 22, 195414.00+2.00Minor21,300
17Jun 21, 201413.82+1.82Minor15,000
18Mar 30, 196213.64+1.64Minor16,400
19Mar 14, 201013.64+1.64Minor14,200
20Jul 29, 199013.43+1.43Minor12,800
21Mar 7, 199413.34+1.34Minor7,900
22Aug 1, 202513.32+1.32Minor13,000
23Aug 12, 198013.29+1.29Minor12,900
24Mar 1, 202313.13+1.13Minor12,900
25Apr 1, 197113.02+1.02Minor11,900
26Jun 24, 202412.94+0.94Minor—
27Jun 10, 197412.92+0.92Minor13,600
28Mar 10, 199212.86+0.86Minor11,600
29May 11, 196312.70+0.70Minor13,600
30Mar 24, 201112.69+0.69Minor10,400
31Jun 23, 202012.63+0.63Minor11,800
32Mar 20, 198612.62+0.62Minor11,500
33Jun 15, 200012.61+0.61Minor11,800
34Mar 12, 199712.49+0.49Minor11,200
35Jun 24, 198412.43+0.43Minor10,900
36Mar 12, 197312.37+0.37Minor10,600
37Apr 29, 197512.36+0.36Minor12,100
38Jun 18, 197812.31+0.31Minor9,320
39Sep 21, 198312.24+0.24Minor10,100
40Jun 25, 198112.22+0.22Minor9,810
41Oct 1, 201612.01+0.01Minor8,160
42Mar 18, 198211.92−0.08Action9,020
43Apr 21, 200511.92−0.08Action7,700
44Apr 3, 200711.85−0.15Action7,500
45Jun 29, 199811.83−0.17Action7,860
46Feb 10, 196611.66−0.34Action9,300
47Mar 30, 196011.54−0.46Action10,100
48Mar 13, 197611.52−0.48Action6,790
49Apr 4, 200611.51−0.49Action6,610
50Sep 29, 197211.36−0.64Action7,060

Other gauges in Butler County

Flood gauges in Butler County
New Hartford12.515.71 ft, Jun 8, 20082

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

NOAA National Water Prediction Service, gauge SHRI4, 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.