Wildwood Lake Dam
Wildwood Lake Dam is an earth dam located in Marshall County, Illinois, built in 1969. It carries a High hazard potential classification.
About Wildwood Lake Dam
The primary purpose of Wildwood Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Lake Wildwood Association, Inc. (private). It impounds the Shaw Creek near Henry.
The dam stands 84 feet tall and stretches 1,385 feet across, creates a reservoir covering 218 acres, has a maximum storage capacity of 9,424 acre-feet, and collects water from a drainage area of 12 square miles. Completed in 1969, 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 05/06/2025.
At 84 feet, this dam is taller than 97% of all dams in the United States.
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 | Marshall |
| Nearest City | Henry |
| River/Stream | Shaw Creek |
| Coordinates | 41.07984, -89.28434 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 84 ft |
| Dam Height | 84 ft |
| Dam Length | 1,385 ft |
| Year Completed | 1969 (57 years old) |
Storage & Hydraulics
| NID Storage | 9,424 acre-ft |
| Max Storage | 9,424 acre-ft |
| Normal Storage | 6,496 acre-ft |
| Surface Area | 218 acres |
| Drainage Area | 12 sq mi |
| Max Discharge | 8,560 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | LAKE WILDWOOD ASSOCIATION, INC. |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 05/06/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IL00134 |
| Federal ID | IL00134 |
| More Info | State Dam Safety Program |