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Illinois River at LaGrange Lock and Dam

Critical Stages
21' - Action
23' - Flood
27' - Moderate
29' - Major

Latest Observation

Updated: 7:00 AM CST 12/6/25

Status: No Flooding

Stage: 7.21 ft

Flow: 6.37 kcfs

Forecast

TimeStage (ft)Flow (kcfs)
12 PM 12/6 7.2 6.3
6 PM 12/6 7.2 6.3
12 AM 12/7 7.2 6.3
6 AM 12/7 7.2 6.3
12 PM 12/7 7.1 6.04
6 PM 12/7 7.1 6.04
12 AM 12/8 7.1 6.04
6 AM 12/8 7.1 6.04
12 PM 12/8 7.1 6.04
6 PM 12/8 7.1 6.04
12 AM 12/9 7 5.79
6 AM 12/9 7 5.79
12 PM 12/9 6.9 5.55
6 PM 12/9 6.9 5.55
12 AM 12/10 6.9 5.55
6 AM 12/10 6.8 5.31
12 PM 12/10 6.8 5.31
6 PM 12/10 6.8 5.31
12 AM 12/11 6.8 5.31
6 AM 12/11 6.7 5.09
12 PM 12/11 6.7 5.09
6 PM 12/11 6.7 5.09
12 AM 12/12 6.7 5.09
6 AM 12/12 6.7 5.09
TimeStage (ft)Flow (kcfs)
7:00 AM 12/6 7.21 6.37
6:30 AM 12/6 7.18 6.25
6:00 AM 12/6 7.18 6.25
5:30 AM 12/6 7.19 6.27
5:00 AM 12/6 7.18 6.25
4:30 AM 12/6 7.17 6.22
4:00 AM 12/6 7.18 6.25
3:30 AM 12/6 7.22 6.45
3:00 AM 12/6 7.21 6.37
2:30 AM 12/6 7.18 6.25
2:00 AM 12/6 7.2 6.3
1:30 AM 12/6 7.22 6.45
1:00 AM 12/6 7.22 6.45
12:30 AM 12/6 7.24 6.6
12:00 AM 12/6 7.22 6.45
11:30 PM 12/5 7.27 6.83
11:00 PM 12/5 7.26 6.75
10:30 PM 12/5 7.24 6.6
10:00 PM 12/5 7.25 6.67
9:30 PM 12/5 -9999 -999
9:00 PM 12/5 7.23 6.52
8:30 PM 12/5 7.26 6.75
8:00 PM 12/5 7.33 7.31
7:30 PM 12/5 7.27 6.83
7:00 PM 12/5 7.26 6.75
6:30 PM 12/5 7.32 7.23
6:00 PM 12/5 7.31 7.15
5:30 PM 12/5 7.31 7.15
5:00 PM 12/5 -9999 -999
4:30 PM 12/5 7.28 6.91
Hydrograph for Illinois River at LaGrange Lock and Dam
36' - Lockmasters house and the lower Corps building at the lock and dam begin flooding.
35.5' - LaGrange Road (County Highway 12) is flooded south of LaGrange Lock and Dam.
29.5' - La Grange Lock Road (County Road 1730N) is flooded just north of the Lock and Dam.
28.8' - County Road 500N south of La Grange is closed due to flooding.
24' - Extensive wetland acreage south of La Grange begins flooding.
23' - Adjacent farmland and wetlands begins flooding. Island Road across the river in western Cass County begins flooding.
20.5' - The lock wall is completely overtopped.
16.5' - The earthen part of the dam is overtopped.
15.5' - Normal pool level (429.0 NGVD29).
14' - Dam goes up at this pool level (427.5 NGVD29).
5.6' - At and below this height, barge traffic will need to consider lowering tonnage to avoid grounding.
DateStage (ft)
Jul 2, 2015 34.66
Apr 27, 2013 34.5
Jun 1, 1995 34.02
Jun 4, 2019 33.89
May 20, 2002 33.34
Apr 19, 1979 32.8
May 22, 2009 32
Jul 29, 1993 32
Apr 29, 1973 32
May 27, 2020 31.35
Jun 6, 2013 31.15
Jun 29, 2010 30.42
Apr 23, 1993 30
May 8, 2017 29.75
Mar 19, 2009 29.72
Jan 20, 2005 29.44
Sep 24, 2008 29.35
Jun 28, 2011 27.86
Nov 6, 2009 27.65
May 4, 2011 27.47

Data provided by the National Weather Service.