Illinois Dams
1,630 dams tracked by the National Inventory of Dams
Total Dams
1,630
High Hazard
251
15.4%
Poor / Unsatisfactory
6
Average Age
61 yrs
Hazard Classification
High251 (15.4%)
Significant360 (22.1%)
Low1,008 (61.8%)
Condition Assessment
Satisfactory8 (0.5%)
Fair6 (0.4%)
Poor / Unsatisfactory6 (0.4%)
Not Rated1,610 (98.8%)
Federal
48
State
68
Local
286
Private
1,153
Tallest Dams
- Refuse Disposal Area175 ft
- Shelbyville Dam138 ft
- Duck Creek Station Dams123 ft
- Devil`s Kitchen Dam121 ft
- Macoupin Energy Refuse Disposal Area 6117 ft
High Hazard Dams
Poor Condition Dams
- Whoopie CatPoor
- Arsenal Power Poor
- Dam A-41Poor
- Lake Chautauqua Upper DamPoor
- Lake Chautauqua Lower DamPoor
All Dams in Illinois
Showing 1076–1100 of 1,630
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| O'Daniel Lodge Lake Dam Jefferson County | 19 | 1973 | Low | Not Available |
| Old Altamont Reservoir Dam Effingham County | 24 | 1934 | Low | Not Available |
| Old Ben/Mine 24/Sediment and Slurry Dam Franklin County | 30 | 1982 | Low | Not Available |
| Old Five Lake Dam Knox County | 35 | 1945 | Low | Not Available |
| Old Gillespie Lake Dam Macoupin County | 35 | 1923 | Low | Not Available |
| Old Mt. Olive City Lake Dam Macoupin County | 37 | 1900 | Significant | Not Available |
| Old Plank Park Basin Dam DuPage County | 10 | — | Low | Not Available |
| Old Reservoir Dam Marion County | 17 | 1943 | Low | Not Available |
| Old Tom Creek WS Str 24 Henderson County | 25 | 1955 | Low | Not Available |
| Old Tom Creek WS Str 25 Henderson County | 25 | 1956 | Low | Not Available |
| Old Tom Creek WS Str 29 Henderson County | 22 | 1956 | Significant | Not Available |
| Olmsted Locks and Dam Ballard County | 67 | 2018 | Significant | Not Available |
| Olson Lake Dam Winnebago County | 24 | 1991 | Low | Not Available |
| Omaha City Reservoir Dam Gallatin County | 22 | 1965 | Low | Not Available |
| Omaha Township Civic Center Dam Gallatin County | 18 | 1980 | Significant | Not Available |
| One Horse Gap Pope County | 36 | 1973 | Significant | Fair |
| Orchard Lake Galena Boulevard Dam Kane County | 11 | — | Low | Not Available |
| Oregon Dam Ogle County | 12 | 1914 | High | Not Available |
| Orland Park Basin Dam Cook County | 7 | 1992 | Low | Not Available |
| Orr Pond Dam Brown County | 26 | 1971 | Low | Not Available |
| Osage Lake Dam Macoupin County | 38 | — | Significant | Not Available |
| Ostermeir Pond Dam Christian County | 22 | 1970 | Low | Not Available |
| Otter Lake Dam Macoupin County | 71 | 1969 | Significant | Not Available |
| Otter Lake Low Flow Dam Macoupin County | 6 | 2008 | Low | Not Available |
| Overby Pond Dam 1 Macoupin County | 31 | 1977 | Low | Not Available |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.