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.

High HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateMissouri
CountyWashington
Nearest CityMineral Point
River/StreamMill Creek-offstream
Coordinates37.94837, -90.71932

Physical Characteristics

Dam TypeEarth
NID Height70 ft
Dam Height70 ft
Dam Length1,430 ft
Year Completed1943 (83 years old)

Storage & Hydraulics

NID Storage22 acre-ft
Max Storage22 acre-ft
Normal Storage22 acre-ft
Surface Area9 acres
Drainage Area0 sq mi
Max Discharge270 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeTailings
OwnerROY BLACK
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection04/07/2022
Emergency Action PlanYes

Identifiers

NID IDMO31154
Federal IDMO31154
More InfoState Dam Safety Program

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