Empire Mine Expanded Tertiary Dam
Empire Mine Expanded Tertiary Dam is an earth dam located in Marquette County, Michigan, built in 1985. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Empire Mine Expanded Tertiary Dam
The primary purpose of Empire Mine Expanded Tertiary 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 Empire Iron Mining Partnership (private). It impounds the Green Creek near Austin.
The dam stands 52 feet tall and stretches 550 feet across, creates a reservoir covering 108 acres, and has a maximum storage capacity of 1,483 acre-feet. Completed in 1985, the structure is 41 years old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. 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 09/30/2019.
At 52 feet, this dam is taller than 93% of dams nationwide.
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Location
| State | Michigan |
| County | Marquette |
| Nearest City | Austin |
| River/Stream | Green Creek |
| Coordinates | 46.37278, -87.60833 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 52 ft |
| Dam Height | 52 ft |
| Dam Length | 550 ft |
| Year Completed | 1985 (41 years old) |
Storage & Hydraulics
| NID Storage | 1,483 acre-ft |
| Max Storage | 1,483 acre-ft |
| Normal Storage | 1,190 acre-ft |
| Surface Area | 108 acres |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Tailings |
| Owner | Empire Iron Mining Partnership |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/30/2019 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MI00810 |
| Federal ID | MI00810 |
| More Info | State Dam Safety Program |