Lake Storey Dam
Lake Storey Dam is an earth dam located in Knox County, Illinois, built in 1942. It carries a High hazard potential classification.
About Lake Storey Dam
The primary purpose of Lake Storey Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by City Of Galesburg (local government). It impounds the Trib South Henderson Creek near Soperville.
The dam stands 53 feet tall and stretches 770 feet across, creates a reservoir covering 109 acres, has a maximum storage capacity of 3,016 acre-feet, and collects water from a drainage area of 6 square miles. Completed in 1942, the structure is well-established, with more than 75 years of service.
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 10/24/2025.
At 53 feet, this dam is taller than 94% 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 | Knox |
| Nearest City | Soperville |
| River/Stream | Trib South Henderson Creek |
| Coordinates | 40.98841, -90.40963 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 53 ft |
| Dam Height | 53 ft |
| Dam Length | 770 ft |
| Year Completed | 1942 (84 years old) |
Storage & Hydraulics
| NID Storage | 3,016 acre-ft |
| Max Storage | 3,016 acre-ft |
| Normal Storage | 1,343 acre-ft |
| Surface Area | 109 acres |
| Drainage Area | 6 sq mi |
| Max Discharge | 33,710 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | CITY OF GALESBURG |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 10/24/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IL00420 |
| Federal ID | IL00420 |
| More Info | State Dam Safety Program |