Greenwood Reservoir Dam
Greenwood Reservoir Dam is an earth dam located in Marquette County, Michigan, built in 1973. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Greenwood Reservoir Dam
The primary purpose of Greenwood Reservoir Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Tilden Magnetite Partnership (private). It impounds the M Br Escanaba River near Gwinn.
The dam stands 60 feet tall and stretches 4,400 feet across, creates a reservoir covering 1,112 acres, and has a maximum storage capacity of 22,750 acre-feet. Completed in 1973, the structure is well into its service life at over 50 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 12/01/2016.
At 60 feet, this dam is taller than 95% of all dams in the United States.
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Location
| State | Michigan |
| County | Marquette |
| Nearest City | Gwinn |
| River/Stream | M Br Escanaba River |
| Coordinates | 46.44235, -87.80167 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 60 ft |
| Dam Height | 60 ft |
| Dam Length | 4,400 ft |
| Year Completed | 1973 (53 years old) |
Storage & Hydraulics
| NID Storage | 22,750 acre-ft |
| Max Storage | 22,750 acre-ft |
| Normal Storage | 18,000 acre-ft |
| Surface Area | 1,112 acres |
| Max Discharge | 23,700 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Tilden Magnetite Partnership |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 12/01/2016 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MI00487 |
| Federal ID | MI00487 |
| More Info | State Dam Safety Program |