Black Tailings Dam
Black Tailings Dam is an earth dam located in Washington County, Missouri, built in 1943. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Black Tailings Dam
The primary purpose of Black Tailings 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 Roy Black (private). It impounds the Mill Creek-offstream near Mineral Point.
The dam stands 70 feet tall and stretches 1,430 feet across, creates a reservoir covering 9 acres, has a maximum storage capacity of 22 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1943, the structure is well-established, with more than 75 years of service.
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 04/07/2022.
At 70 feet, this dam is taller than 96% 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 | Washington |
| Nearest City | Mineral Point |
| River/Stream | Mill Creek-offstream |
| Coordinates | 37.94837, -90.71932 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 70 ft |
| Dam Height | 70 ft |
| Dam Length | 1,430 ft |
| Year Completed | 1943 (83 years old) |
Storage & Hydraulics
| NID Storage | 22 acre-ft |
| Max Storage | 22 acre-ft |
| Normal Storage | 22 acre-ft |
| Surface Area | 9 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 270 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Tailings |
| Owner | ROY BLACK |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/07/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MO31154 |
| Federal ID | MO31154 |
| More Info | State Dam Safety Program |