Lake Sainte Louise Dam
Lake Sainte Louise Dam is an earth dam located in St. Charles County, Missouri, built in 1967. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Lake Sainte Louise Dam
The primary purpose of Lake Sainte Louise Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Lake Saint Louis Comm. (private). It impounds the Branch Peruque Creek near O'fallon.
The dam stands 52 feet tall and stretches 790 feet across, creates a reservoir covering 70 acres, has a maximum storage capacity of 1,420 acre-feet, and collects water from a drainage area of 1 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. 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 08/02/2022.
At 52 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 | O'fallon |
| River/Stream | Branch Peruque Creek |
| Coordinates | 38.80038, -90.79054 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 52 ft |
| Dam Height | 52 ft |
| Dam Length | 790 ft |
| Year Completed | 1967 (59 years old) |
Storage & Hydraulics
| NID Storage | 1,420 acre-ft |
| Max Storage | 1,420 acre-ft |
| Normal Storage | 1,170 acre-ft |
| Surface Area | 70 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 2,544 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | LAKE SAINT LOUIS COMM. |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/02/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MO10490 |
| Federal ID | MO10490 |
| More Info | State Dam Safety Program |