Horton Lake Dam
Horton Lake Dam is an earth dam located in Hancock County, Illinois, built in 1967. It carries a High hazard potential classification.
About Horton Lake Dam
The primary purpose of Horton Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Illinois Department Of Natural Resources (state). It impounds the Trib Mississippi River near Nauvoo.
The dam stands 50 feet tall and stretches 480 feet across, creates a reservoir covering 13 acres, has a maximum storage capacity of 287 acre-feet, and collects water from a drainage area of 33 square miles. Completed in 1967, the structure is well into its service life at over 50 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. An emergency action plan is in place for this dam. The most recent inspection on record was 04/08/2024.
At 50 feet, this dam is taller than 93% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Illinois dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Illinois |
| County | Hancock |
| Nearest City | Nauvoo |
| River/Stream | Trib Mississippi River |
| Coordinates | 40.54636, -91.38474 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 50 ft |
| Dam Height | 50 ft |
| Dam Length | 480 ft |
| Year Completed | 1967 (59 years old) |
Storage & Hydraulics
| NID Storage | 287 acre-ft |
| Max Storage | 287 acre-ft |
| Normal Storage | 158 acre-ft |
| Surface Area | 13 acres |
| Drainage Area | 33 sq mi |
| Max Discharge | 2,809 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | ILLINOIS DEPARTMENT OF NATURAL RESOURCES |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 04/08/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IL00256 |
| Federal ID | IL00256 |
| More Info | State Dam Safety Program |