Lake Hanna Dam
Lake Hanna Dam is an earth dam located in St. Francois County, Missouri, built in 1967. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Lake Hanna Dam
The primary purpose of Lake Hanna Dam is tailings. Tailings dams contain waste material from mining operations — typically a slurry of finely ground rock left over after valuable minerals have been extracted. These structures require ongoing monitoring because tailings can contain heavy metals and other contaminants. The dam is owned by Lake Hanna Association. Inc. (private). It impounds the Brewers Creek near Syenite.
The dam stands 38 feet tall and stretches 1,650 feet across, creates a reservoir covering 135 acres, has a maximum storage capacity of 2,025 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 01/11/2022.
At 38 feet, this dam is taller than 85% 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. Francois |
| Nearest City | Syenite |
| River/Stream | Brewers Creek |
| Coordinates | 37.65073, -90.58035 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 38 ft |
| Dam Height | 38 ft |
| Dam Length | 1,650 ft |
| Year Completed | 1967 (59 years old) |
Storage & Hydraulics
| NID Storage | 2,025 acre-ft |
| Max Storage | 2,025 acre-ft |
| Normal Storage | 816 acre-ft |
| Surface Area | 135 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 5,003 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Tailings |
| Owner | LAKE HANNA Association. INC. |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 01/11/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MO30314 |
| Federal ID | MO30314 |
| More Info | State Dam Safety Program |