Ellsworth
Ellsworth is a concrete dam located in Hancock County, Maine, built in 1907. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Ellsworth
The primary purpose of Ellsworth is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Black Bear Hydro Partners, Llc (private). It impounds the Union River near Ellsworth.
The dam stands 62 feet tall and stretches 377 feet across, creates a reservoir covering 125 acres, has a maximum storage capacity of 2,500 acre-feet, and collects water from a drainage area of 613 square miles. Completed in 1907, the structure is over a century 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 09/21/2022.
At 62 feet, this dam is taller than 95% 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 Maine 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.
Location
| State | Maine |
| County | Hancock |
| Nearest City | Ellsworth |
| River/Stream | Union River |
| Coordinates | 44.54466, -68.42954 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 62 ft |
| Dam Height | 62 ft |
| Dam Length | 377 ft |
| Year Completed | 1907 (119 years old) |
Storage & Hydraulics
| NID Storage | 2,500 acre-ft |
| Max Storage | 2,500 acre-ft |
| Normal Storage | 2,500 acre-ft |
| Surface Area | 125 acres |
| Drainage Area | 613 sq mi |
| Max Discharge | 17,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Black Bear Hydro Partners, LLC |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/21/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | ME00263 |
| Federal ID | ME00263 |
| More Info | State Dam Safety Program |