Greenwood Reservoir Dam Reservoir Report
Last Updated: December 5, 2025
Greenwood Reservoir Dam in Gwinn, Michigan, is a privately owned structure that serves as a crucial water supply source in Marquette County.
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Summary
Completed in 1973, this Earth-type dam stands at a height of 60 feet and has a storage capacity of 22,750 acre-feet with a normal storage level of 18,000 acre-feet. Situated on the M Br Escanaba River, the dam plays a vital role in regulating the flow of water and ensuring a stable water supply for the surrounding area.
The dam's spillway, with a controlled design and a width of 280 feet, helps manage potential excess water while maintaining the structural integrity of the reservoir. In terms of safety measures, the dam has been assessed as satisfactory, but it holds a significant hazard potential, leading to a very high risk rating. Regular inspections are conducted, with the last assessment taking place in December 2016. Despite its age, Greenwood Reservoir Dam continues to play a crucial role in water resource management and climate resilience efforts in the region.
As water resource and climate enthusiasts, the Greenwood Reservoir Dam is a fascinating example of the intersection between human infrastructure and natural ecosystems. Its careful design and management by the Michigan DEGLE ensure the sustainable utilization of water resources while mitigating potential risks associated with dam operations. The dam's presence highlights the importance of maintaining critical infrastructure for water supply purposes and underscores the ongoing need for monitoring and assessment to ensure the safety and resilience of our water systems in the face of changing climate conditions.
Year Completed |
1973 |
Dam Length |
4400 |
Dam Height |
60 |
River Or Stream |
M Br Escanaba River |
Primary Dam Type |
Earth |
Surface Area |
1112 |
Hydraulic Height |
54 |
Nid Storage |
22750 |
Structural Height |
60 |
Hazard Potential |
Significant |
Nid Height |
60 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
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