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Sangamon River at Petersburg

Highest listed crest 33.90 ftFlood stage 23.0 ft36 crests since 1943

The Sangamon River at Petersburg crested at major flood stage 1 time among the 36 crests the National Weather Service lists from 1943 to 2024. The highest, 33.90 ft on May 20, 1943, was major flooding, 10.90 feet above flood stage. 3 other gauges on the Sangamon River crested above flood stage within a week of it, 2 at their own highest listed crest.

The gauge

Highest listed crest
33.90 ft
May 20, 1943
Flood stage
23.0 ft
Major flooding from 33.0 ft
Crests at major
1
101st of 177 gauges in Illinois
Most recent flood crest
May 20, 2020
23.80 ft, minor flooding
Location
Menard County
Illinois

Flood stages

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

Flood categories, Sangamon River at Petersburg
Action stage18.010Jan 26, 2024The level at which the NWS or its partners begin to take action
Flood stage (minor)23.09May 20, 2020Minimal or no property damage, but possibly some public threat
Moderate flood stage24.012Dec 31, 2015Some inundation of structures and roads near the stream
Major flood stage33.01May 20, 1943Extensive inundation of structures and roads

Every listed crest

36 crests from 1943 to 2024. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Sangamon River at Petersburg, 1943 to 2024 101520253035ft Flood stage 23.0 ftMajor 33.0 ft May 20, 1943: 33.90 ft, major floodingApr 21, 1969: 24.20 ft, moderate floodingMay 3, 1970: 26.10 ft, moderate floodingJan 25, 1974: 26.50 ft, moderate floodingJan 12, 1975: 23.10 ft, minor floodingJun 23, 1990: 23.04 ft, minor floodingApr 14, 1994: 29.84 ft, moderate floodingMay 11, 1996: 27.45 ft, moderate floodingMay 14, 2002: 30.75 ft, moderate floodingJan 10, 2005: 23.62 ft, minor floodingJan 17, 2005: 26.30 ft, moderate floodingMay 21, 2009: 22.75 ft, action stageNov 3, 2009: 24.24 ft, moderate floodingNov 21, 2009: 24.10 ft, moderate floodingDec 28, 2009: 23.40 ft, minor floodingJun 26, 2010: 23.71 ft, minor flooding; 19,900 cubic feet per secondJun 21, 2011: 22.14 ft, action stage; 17,500 cubic feet per secondMay 3, 2012: 11.11 ft, below flood stage; 4,350 cubic feet per secondApr 23, 2013: 25.67 ft, moderate flooding; 24,200 cubic feet per secondJun 4, 2013: 24.05 ft, moderate flooding; 21,300 cubic feet per secondFeb 22, 2014: 18.07 ft, action stage; 12,200 cubic feet per secondJun 30, 2015: 21.75 ft, action stage; 17,600 cubic feet per secondDec 31, 2015: 30.55 ft, moderate flooding; 44,800 cubic feet per secondMay 7, 2017: 23.92 ft, minor flooding; 21,800 cubic feet per secondJan 4, 2019: 19.45 ft, action stage; 14,200 cubic feet per secondMar 17, 2019: 17.47 ft, below flood stage; 11,600 cubic feet per secondMay 4, 2019: 23.21 ft, minor flooding; 20,500 cubic feet per secondJun 25, 2019: 23.59 ft, minor flooding; 21,200 cubic feet per secondJan 16, 2020: 22.56 ft, action stage; 19,300 cubic feet per secondMar 23, 2020: 17.80 ft, below flood stage; 12,000 cubic feet per secondMay 3, 2020: 22.59 ft, action stage; 19,300 cubic feet per secondMay 20, 2020: 23.80 ft, minor flooding; 21,600 cubic feet per secondMay 22, 2021: 18.97 ft, action stage; 13,500 cubic feet per secondJul 4, 2021: 19.30 ft, action stage; 13,900 cubic feet per secondFeb 25, 2022: 17.64 ft, below flood stage; 11,800 cubic feet per secondJan 26, 2024: 18.73 ft, action stage Highest, 33.90 ft, May 20, 1943 1960198020002020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Sangamon River at Petersburg 1940s: 1 1950s: 0 1960s: 1 1970s: 3 1980s: 0 1990s: 3 2000s: 6 2010s: 7 7 2020s: 1 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

Highest listed crests, Sangamon River at Petersburg
1May 20, 194333.90+10.90Major—
2May 14, 200230.75+7.75Moderate—
3Dec 31, 201530.55+7.55Moderate44,800
4Apr 14, 199429.84+6.84Moderate—
5May 11, 199627.45+4.45Moderate—
6Jan 25, 197426.50+3.50Moderate—
7Jan 17, 200526.30+3.30Moderate—
8May 3, 197026.10+3.10Moderate—
9Apr 23, 201325.67+2.67Moderate24,200
10Nov 3, 200924.24+1.24Moderate—
11Apr 21, 196924.20+1.20Moderate—
12Nov 21, 200924.10+1.10Moderate—
13Jun 4, 201324.05+1.05Moderate21,300
14May 7, 201723.92+0.92Minor21,800
15May 20, 202023.80+0.80Minor21,600
16Jun 26, 201023.71+0.71Minor19,900
17Jan 10, 200523.62+0.62Minor—
18Jun 25, 201923.59+0.59Minor21,200
19Dec 28, 200923.40+0.40Minor—
20May 4, 201923.21+0.21Minor20,500
21Jan 12, 197523.10+0.10Minor—
22Jun 23, 199023.04+0.04Minor—
23May 21, 200922.75−0.25Action—
24May 3, 202022.59−0.41Action19,300
25Jan 16, 202022.56−0.44Action19,300
26Jun 21, 201122.14−0.86Action17,500
27Jun 30, 201521.75−1.25Action17,600
28Jan 4, 201919.45−3.55Action14,200
29Jul 4, 202119.30−3.70Action13,900
30May 22, 202118.97−4.03Action13,500
31Jan 26, 202418.73−4.27Action—
32Feb 22, 201418.07−4.93Action12,200
33Mar 23, 202017.80−5.20Below flood stage12,000
34Feb 25, 202217.64−5.36Below flood stage11,800
35Mar 17, 201917.47−5.53Below flood stage11,600
36May 3, 201211.11−11.89Below flood stage4,350

The worst floods along the Sangamon River

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

May 20, 1943: 33.90 ft here, major flooding

  • OakfordIL · May 20, 1943 · 478.51 ft · Major · its highest
  • RivertonIL · May 19, 1943 · 31.52 ft · Major · its highest
  • MonticelloIL · May 18, 1943 · 17.67 ft · Moderate

May 14, 2002: 30.75 ft here, moderate flooding

  • ChandlervilleIL · May 16, 2002 · 462.70 ft · Major
  • RivertonIL · May 14, 2002 · 30.07 ft · Major
  • OakfordIL · May 15, 2002 · 476.73 ft · Moderate
  • MonticelloIL · May 14, 2002 · 15.77 ft · Minor

December 31, 2015: 30.55 ft here, moderate flooding

  • ChandlervilleIL · Jan 2, 2016 · 463.20 ft · Major · its highest
  • RivertonIL · Dec 31, 2015 · 30.13 ft · Major
  • OakfordIL · Jan 1, 2016 · 477.67 ft · Moderate
  • MonticelloIL · Dec 29, 2015 · 18.56 ft · Moderate

Gauges on the Sangamon River

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

Flood gauges on the Sangamon River
MonticelloIL13.019.06 ft, Apr 13, 19940
Petersburg this gaugeIL23.033.90 ft, May 20, 19431
RivertonIL23.031.52 ft, May 19, 19433
ChandlervilleIL456.6463.20 ft, Jan 2, 20162
OakfordIL471.0478.51 ft, May 20, 19431

Other gauges in Menard County

Flood gauges in Menard County
Greenview16.020.50 ft, May 19, 19432
Oakford471.0478.51 ft, May 20, 19431

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

NOAA National Water Prediction Service, gauge PETI2, 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.