Long Lake Dam
Long Lake Dam is an earth dam located in Fulton County, Illinois, built in 1965. It carries a High hazard potential classification.
About Long Lake Dam
The primary purpose of Long Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Wee-ma-tuk Hills Inc. (private). It impounds the Put Creek-offstream near Seville.
The dam stands 20 feet tall and stretches 236 feet across, and has a maximum storage capacity of 140 acre-feet. Completed in 1965, 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. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 11/21/2022.
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 | Fulton |
| Nearest City | Seville |
| River/Stream | Put Creek-offstream |
| Coordinates | 40.52871, -90.14075 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 20 ft |
| Dam Height | 20 ft |
| Dam Length | 236 ft |
| Year Completed | 1965 (61 years old) |
Storage & Hydraulics
| NID Storage | 140 acre-ft |
| Max Storage | 140 acre-ft |
| Normal Storage | 80 acre-ft |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | WEE-MA-TUK HILLS INC. |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 11/21/2022 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IL01120 |
| Federal ID | IL01120 |
| More Info | State Dam Safety Program |