Femme Osage Lake Dam
Femme Osage Lake Dam is an earth dam located in St. Charles County, Missouri, built in 1980. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Femme Osage Lake Dam
The primary purpose of Femme Osage Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is private-owned. It impounds the Femme Osage near Weldon Springs.
The dam stands 50 feet tall and stretches 560 feet across, creates a reservoir covering 72 acres, has a maximum storage capacity of 973 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1980, the structure is 46 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. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 04/19/2023.
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 Missouri 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 | Missouri |
| County | St. Charles |
| Nearest City | Weldon Springs |
| River/Stream | Femme Osage |
| Coordinates | 38.66134, -90.84639 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 50 ft |
| Dam Height | 50 ft |
| Dam Length | 560 ft |
| Year Completed | 1980 (46 years old) |
Storage & Hydraulics
| NID Storage | 973 acre-ft |
| Max Storage | 973 acre-ft |
| Normal Storage | 973 acre-ft |
| Surface Area | 72 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 1,975 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/19/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MO31842 |
| Federal ID | MO31842 |
| More Info | State Dam Safety Program |