Cadet Mine Tailings Dam

Cadet Mine Tailings Dam is an earth dam located in Washington County, Missouri, built in 1978. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Cadet Mine Tailings Dam

The primary purpose of Cadet Mine 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 private-owned. It impounds the Tr-mill Creek near Tiff.

The dam stands 97 feet tall and stretches 3,800 feet across, creates a reservoir covering 2 acres, has a maximum storage capacity of 103 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1978, the structure is 48 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 09/02/2021.

At 97 feet, this dam is taller than 98% 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 CityTiff
River/StreamTr-mill Creek
Coordinates37.99444, -90.66561

Physical Characteristics

Dam TypeEarth
NID Height97 ft
Dam Height97 ft
Dam Length3,800 ft
Year Completed1978 (48 years old)

Storage & Hydraulics

NID Storage103 acre-ft
Max Storage103 acre-ft
Normal Storage103 acre-ft
Surface Area2 acres
Drainage Area0 sq mi
Spillway TypeUncontrolled

Ownership & Safety

PurposeTailings
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection09/02/2021
Emergency Action PlanYes

Identifiers

NID IDMO30715
Federal IDMO30715
More InfoState Dam Safety Program

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