Riverine Flood Risk in Illinois

All Illinois counties ranked by FEMA National Risk Index riverine flood score

Riverine Flood risk — rivers and streams overflowing their banks after heavy rain or snowmelt — is rated for 102 of 102 Illinois counties in FEMA's National Risk Index. Cook County carries the state's highest riverine flood score at 99.9, with $1.10B in expected annual riverine flood losses.

7 Illinois counties are rated High or Very High for riverine flood, and expected annual losses from riverine flood total roughly $2.92B statewide. The full ranking below links to each county's complete 18-hazard risk profile.

County Rankings — Riverine Flood

#CountyRiverine Flood ScoreRatingAnn. Freq.Ann. Loss
1 Cook County
99.9
Very High 5.89 / yr $1.10B
2 DuPage County
98.0
High 2.82 / yr $195M
3 Will County
97.9
High 3.00 / yr $193M
4 Lake County
97.2
High 2.00 / yr $155M
5 Kane County
95.5
High 1.79 / yr $99M
6 St. Clair County
94.5
High 1.79 / yr $72M
7 Winnebago County
94.4
High 2.07 / yr $68M
8 McHenry County
93.1
Medium 1.11 / yr $85M
9 Kankakee County
92.5
Medium 1.46 / yr $48M
10 Madison County
92.3
Medium 1.39 / yr $56M
11 Sangamon County
91.2
Medium 2.18 / yr $47M
12 Champaign County
90.4
Medium 1.82 / yr $43M
13 Peoria County
88.7
Medium 1.54 / yr $32M
14 LaSalle County
88.2
Medium 2.00 / yr $33M
15 McLean County
85.2
Medium 1.29 / yr $33M
16 Tazewell County
84.4
Medium 1.46 / yr $28M
17 Macon County
83.3
Medium 1.36 / yr $21M
18 DeKalb County
83.0
Medium 1.14 / yr $24M
19 Livingston County
81.1
Medium 1.29 / yr $22M
20 Kendall County
79.7
Medium 1.00 / yr $34M
21 Iroquois County
79.6
Medium 1.39 / yr $20M
22 Rock Island County
79.5
Medium 3.07 / yr $17M
23 Stephenson County
77.9
Medium 1.25 / yr $16M
24 Ogle County
77.0
Medium 1.18 / yr $21M
25 Jackson County
76.5
Medium 6.07 / yr $13M
26 Vermilion County
76.5
Medium 1.89 / yr $14M
27 Coles County
74.5
Medium 1.68 / yr $17M
28 Whiteside County
70.1
Low 1.86 / yr $13M
29 Williamson County
69.9
Low 2.04 / yr $12M
30 Macoupin County
68.7
Low 0.96 / yr $11M
31 Marion County
68.1
Low 1.14 / yr $10M
32 Grundy County
66.5
Low 1.25 / yr $22M
33 Franklin County
65.7
Low 4.04 / yr $8M
34 Clinton County
64.0
Low 0.79 / yr $11M
35 Boone County
63.9
Low 0.93 / yr $11M
36 Bureau County
63.4
Low 0.86 / yr $10M
37 Lee County
62.5
Low 0.93 / yr $11M
38 Morgan County
61.2
Low 1.39 / yr $9M
39 Adams County
60.7
Low 1.29 / yr $10M
40 Douglas County
60.1
Low 1.00 / yr $8M
41 Jefferson County
59.0
Low 1.54 / yr $8M
42 Montgomery County
58.7
Low 0.75 / yr $8M
43 Jo Daviess County
58.5
Low 1.54 / yr $8M
44 Lawrence County
58.2
Low 1.32 / yr $7M
45 Randolph County
57.8
Low 1.04 / yr $8M
46 Fulton County
57.6
Low 1.68 / yr $9M
47 Saline County
57.4
Low 1.82 / yr $6M
48 Logan County
53.7
Low 1.57 / yr $7M
49 Henry County
51.5
Low 1.79 / yr $9M
50 Woodford County
51.5
Low 1.25 / yr $12M
51 Perry County
49.8
Low 1.86 / yr $6M
52 Fayette County
49.5
Low 0.89 / yr $6M
53 Knox County
49.4
Low 1.36 / yr $6M
54 Effingham County
49.2
Low 2.04 / yr $7M
55 Moultrie County
49.1
Low 0.93 / yr $5M
56 Shelby County
48.3
Low 1.86 / yr $7M
57 Mason County
47.2
Low 0.93 / yr $6M
58 Carroll County
46.5
Low 1.36 / yr $5M
59 White County
44.3
Low 6.64 / yr $5M
60 Crawford County
43.7
Low 1.68 / yr $7M
61 Piatt County
43.7
Low 0.71 / yr $6M
62 Massac County
43.0
Low 4.21 / yr $4M
63 Christian County
41.5
Low 1.64 / yr $6M
64 Richland County
41.3
Low 1.21 / yr $4M
65 Alexander County
40.5
Low 7.25 / yr $3M
66 Washington County
39.0
Low 0.57 / yr $5M
67 Union County
38.9
Low 2.32 / yr $4M
68 Clay County
38.9
Low 2.00 / yr $4M
69 Johnson County
37.9
Low 0.82 / yr $3M
70 Gallatin County
36.0
Low 5.68 / yr $3M
71 Ford County
35.6
Low 1.07 / yr $4M
72 Wayne County
35.4
Low 3.21 / yr $4M
73 Marshall County
35.1
Low 1.00 / yr $4M
74 Pike County
33.7
Very Low 0.82 / yr $4M
75 Cumberland County
33.5
Very Low 1.11 / yr $3M
76 Monroe County
32.3
Very Low 1.04 / yr $6M
77 Clark County
31.0
Very Low 1.21 / yr $4M
78 Bond County
30.5
Very Low 0.71 / yr $3M
79 De Witt County
30.3
Very Low 0.68 / yr $4M
80 Edgar County
30.0
Very Low 1.32 / yr $4M
81 Menard County
29.4
Very Low 0.64 / yr $3M
82 Jasper County
28.4
Very Low 1.54 / yr $4M
83 Cass County
28.1
Very Low 1.07 / yr $3M
84 Wabash County
25.8
Very Low 4.18 / yr $3M
85 Henderson County
24.7
Very Low 1.89 / yr $2M
86 Hancock County
24.2
Very Low 2.71 / yr $2M
87 Edwards County
21.5
Very Low 1.04 / yr $2M
88 McDonough County
21.1
Very Low 2.07 / yr $2M
89 Putnam County
19.6
Very Low 0.43 / yr $2M
90 Jersey County
18.0
Very Low 1.11 / yr $3M
91 Pope County
17.2
Very Low 2.54 / yr $2M
92 Calhoun County
16.1
Very Low 0.86 / yr $2M
93 Hardin County
15.5
Very Low 1.86 / yr $2M
94 Pulaski County
15.1
Very Low 4.68 / yr $1M
95 Greene County
13.2
Very Low 0.61 / yr $2M
96 Hamilton County
12.5
Very Low 1.39 / yr $2M
97 Stark County
11.2
Very Low 0.71 / yr $2M
98 Warren County
11.0
Very Low 0.79 / yr $2M
99 Mercer County
9.2
Very Low 1.64 / yr $2M
100 Schuyler County
8.2
Very Low 1.50 / yr $875K
101 Scott County
5.1
Very Low 1.29 / yr $1M
102 Brown County
4.1
Very Low 0.64 / yr $653K

102 Illinois counties with measurable riverine flood risk. See the national riverine flood ranking or all Illinois counties by overall risk.

Frequently Asked Questions

Which Illinois county has the highest riverine flood risk?

Cook County has the highest FEMA riverine flood risk score in Illinois at 99.9 (Very High), with $1.10B in expected annual losses and about 5.89 events per year.

How many Illinois counties face significant riverine flood risk?

102 Illinois counties record measurable riverine flood risk in FEMA's National Risk Index; 7 of them are rated High or Very High.

Other Hazards in Illinois

Cold Wave Drought Earthquake Hail Heat Wave Hurricane Ice Storm Landslide Lightning Strong Wind Tornado Wildfire Winter Weather