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Rock River at Rockford (Fordam Dam)

Highest listed crest 6.50 ftFlood stage 4.0 ft20 crests since 1881

The Rock River at Rockford (Fordam Dam) crested at major flood stage 1 time among the 20 crests the National Weather Service lists from 1881 to 2022. The highest, 6.50 ft on April 20, 1881, was major flooding, 2.50 feet above flood stage. 1 other gauge on the Rock River crested above flood stage within a week of it, 1 at its own highest listed crest.

The gauge

Highest listed crest
6.50 ft
April 20, 1881
Flood stage
4.0 ft
Major flooding from 6.0 ft
Crests at major
1
101st of 177 gauges in Illinois
Most recent flood crest
March 17, 2019
4.06 ft, minor flooding
Location
Winnebago County
Near Rockford (1.7 mi), Loves Park (7.0 mi), Machesney Park (7.9 mi)

Flood stages

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

Flood categories, Rock River at Rockford (Fordam Dam)
Action stage3.55Oct 7, 2018The level at which the NWS or its partners begin to take action
Flood stage (minor)4.04Mar 17, 2019Minimal or no property damage, but possibly some public threat
Moderate flood stage5.07Mar 26, 1975Some inundation of structures and roads near the stream
Major flood stage6.01Apr 20, 1881Extensive inundation of structures and roads

Every listed crest

20 crests from 1881 to 2022. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Rock River at Rockford (Fordam Dam), 1881 to 2022 34567ft Flood stage 4.0 ftMajor 6.0 ft Apr 20, 1881: 6.50 ft, major floodingMar 29, 1916: 5.50 ft, moderate floodingMar 18, 1929: 5.20 ft, moderate floodingFeb 21, 1937: 5.20 ft, moderate floodingJun 5, 1954: 3.80 ft, action stageApr 4, 1959: 5.17 ft, moderate floodingJan 12, 1960: 4.30 ft, minor floodingApr 4, 1960: 5.08 ft, moderate floodingNov 16, 1961: 4.50 ft, minor floodingMar 27, 1962: 4.10 ft, minor floodingApr 23, 1973: 5.60 ft, moderate floodingMar 26, 1975: 5.50 ft, moderate floodingApr 3, 1979: 3.80 ft, action stageJul 28, 2017: 3.28 ft, below flood stageJan 24, 2018: 3.75 ft, action stageFeb 26, 2018: 3.66 ft, action stageOct 7, 2018: 3.61 ft, action stageMar 17, 2019: 4.06 ft, minor floodingAug 11, 2020: 3.38 ft, below flood stageDec 21, 2022: 3.26 ft, below flood stage Highest, 6.50 ft, Apr 20, 1881 1900192019401960198020002020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Rock River at Rockford (Fordam Dam) 1880s: 1 1890s: 0 1900s: 0 1910s: 1 1920s: 1 1930s: 1 1940s: 0 1950s: 1 1960s: 4 4 1970s: 2 1980s: 0 1990s: 0 2000s: 0 2010s: 1 2020s: 0 1880s1900s1920s1940s1960s1980s2000s2020s
  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.
  3. 3 crests measured on an earlier gauge datum are left out: 3.71 ft on Aug 7, 1969; 3.90 ft on Feb 19, 1971; 3.79 ft on Mar 12, 1974.

Highest crests

Highest listed crests, Rock River at Rockford (Fordam Dam)
1Apr 20, 18816.50+2.50Major—
2Apr 23, 19735.60+1.60Moderate—
3Mar 29, 19165.50+1.50Moderate—
4Mar 26, 19755.50+1.50Moderate—
5Mar 18, 19295.20+1.20Moderate—
6Feb 21, 19375.20+1.20Moderate—
7Apr 4, 19595.17+1.17Moderate—
8Apr 4, 19605.08+1.08Moderate—
9Nov 16, 19614.50+0.50Minor—
10Jan 12, 19604.30+0.30Minor—
11Mar 27, 19624.10+0.10Minor—
12Mar 17, 20194.06+0.06Minor—
13Jun 5, 19543.80−0.20Action—
14Apr 3, 19793.80−0.20Action—
15Jan 24, 20183.75−0.25Action—
16Feb 26, 20183.66−0.34Action—
17Oct 7, 20183.61−0.39Action—
18Aug 11, 20203.38−0.62Below flood stage—
19Jul 28, 20173.28−0.72Below flood stage—
20Dec 21, 20223.26−0.74Below flood stage—

The worst floods along the Rock River

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

April 20, 1881: 6.50 ft here, major flooding

April 23, 1973: 5.60 ft here, moderate flooding

  • DixonIL · Apr 20, 1973 · 20.50 ft · Major · its highest
  • ByronIL · Apr 20, 1973 · 17.80 ft · Major · its highest
  • JoslinIL · Apr 23, 1973 · 17.74 ft · Major
  • MolineIL · Apr 27, 1973 · 16.15 ft · Major
  • RocktonIL · Apr 22, 1973 · 13.40 ft · Moderate
  • Latham ParkIL · Apr 23, 1973 · 13.30 ft · Moderate
  • Rockford (Auburn Street)IL · Apr 23, 1973 · 6.80 ft · Minor

March 29, 1916: 5.50 ft here, moderate flooding

  • AftonWI · Apr 1, 1916 · 10.12 ft · Minor

Gauges on the Rock River

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

Flood gauges on the Rock River
AftonWI9.013.51 ft, Jun 21, 20083
ByronIL13.017.80 ft, Apr 20, 19735
ComoIL12.515.64 ft, Jul 23, 20170
DixonIL16.020.50 ft, Apr 20, 19731
Fort AtkinsonWI16.020.90 ft, Jun 15, 20082
JeffersonWI10.015.64 ft, Jun 19, 20081
Lake KoshkonongWI10.015.13 ft, Jun 21, 20086
Latham ParkIL9.014.70 ft, Mar 26, 19753
Lebanon-3 E-Hwy MM bridgeWI10.014.01 ft, Jun 15, 20081
MolineIL12.016.53 ft, Apr 22, 201334
NewvilleWI6.58.51 ft, Apr 23, 20131
Rockford (Auburn Street)IL6.010.00 ft, Apr 20, 18811
Rockford (Fordam Dam) this gaugeIL4.06.50 ft, Apr 20, 18811
RocktonIL10.015.54 ft, Mar 25, 19754
WatertownWI5.57.81 ft, Jun 13, 20082
JoslinIL12.019.24 ft, Jun 7, 200224

Other gauges in Winnebago County

Flood gauges in Winnebago County
Perryville12.023.54 ft, Jul 18, 19961
Shirland12.018.08 ft, Mar 25, 197511
Latham Park9.014.70 ft, Mar 26, 19753
Rockford (Auburn Street)6.010.00 ft, Apr 20, 18811
Rockton10.015.54 ft, Mar 25, 19754

Winnebago County: every hazard · River floods across the country · Illinois

NOAA National Water Prediction Service, gauge RFDI2, 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.