Ellsworth Reservoir Report
Last Updated: December 20, 2025
Ellsworth is a captivating hydroelectric dam located in Hancock, Maine, on the Union River.
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Summary
Completed in 1907, this dam stands at a height of 62.3 feet and has a length of 377 feet, with a storage capacity of 2500 acre-feet. The dam serves multiple purposes, including hydroelectric power generation and recreation, making it an essential part of the region's water resource infrastructure.
Managed by the Federal Energy Regulatory Commission, Ellsworth has a high hazard potential due to its size and location. Despite its age, the dam continues to play a crucial role in water management and energy production in the area. With a maximum discharge of 17,000 cubic feet per second and a surface area of 125 acres, Ellsworth is a key feature of the local landscape and contributes to the overall climate resilience of the region.
Although specific details on the condition assessment of Ellsworth are not available, its risk assessment indicates a moderate level of risk. With a focus on risk management measures and emergency preparedness, this dam remains an important structure for water resource and climate enthusiasts to monitor and support in ensuring its continued safe operation for the community.
Year Completed |
1907 |
Dam Length |
377 |
Dam Height |
62.3 |
River Or Stream |
Union River |
Surface Area |
125 |
Drainage Area |
613 |
Nid Storage |
2500 |
Hazard Potential |
High |
Nid Height |
62 |
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.
Ellsworth