St. Joe State Park Dam
St. Joe State Park Dam is a rockfill dam located in St. Francois County, Missouri, built in 1965. It carries a High hazard potential classification and has a satisfactory condition assessment.
About St. Joe State Park Dam
The primary purpose of St. Joe State Park 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 Mo. Dnr Parks (state). It impounds the Shaw Branch-flat River near Flat River.
The dam stands 134 feet tall and stretches 2,930 feet across, creates a reservoir covering 970 acres, has a maximum storage capacity of 54,166 acre-feet, and collects water from a drainage area of 5 square miles. 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. 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 134 feet, this dam is taller than 99% 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 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 | Flat River |
| River/Stream | Shaw Branch-flat River |
| Coordinates | 37.83235, -90.51467 |
Physical Characteristics
| Dam Type | Rockfill |
| NID Height | 134 ft |
| Dam Height | 130 ft |
| Dam Length | 2,930 ft |
| Year Completed | 1965 (61 years old) |
Storage & Hydraulics
| NID Storage | 54,166 acre-ft |
| Max Storage | 54,166 acre-ft |
| Normal Storage | 37,180 acre-ft |
| Surface Area | 970 acres |
| Drainage Area | 5 sq mi |
| Max Discharge | 12,100 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Tailings |
| Owner | MO. DNR PARKS |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 01/11/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MO30277 |
| Federal ID | MO30277 |
| More Info | State Dam Safety Program |