Stillwater

Stillwater River· Penobscot, Maine· Built 1902· Concrete· 25 ft tall
Low Hazard Hydroelectric Recreation Private

Key Takeaway

Stillwater is classified as low hazard in Maine. It was completed in 1902 and is 124 years old. Its primary use is hydroelectric.

Physical Details

Dam Height 25 ft (taller than 83.1% in ME)
Dam Length1,720 ft
Dam TypeConcrete
Max Storage1.9K acre-ft
Normal Storage1.9K acre-ft
Surface Area191 acres
Drainage Area7,602 sq mi
Max Discharge25,000 cfs
Year Completed1902 (124 years old)
NID IDME00139

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: September 14, 2022
State Regulated: No

Ownership

Black Bear Hydro Partners, LLC, Black Bear Development Holdings, LLC & Black Bear SO, LLC

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Stillwater?

Stillwater is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Stillwater?

Stillwater is owned by Black Bear Hydro Partners, LLC, Black Bear Development Holdings, LLC & Black Bear SO, LLC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Stillwater built?

Stillwater was completed in 1902, making it 124 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Stillwater?

Stillwater serves the following purposes: Hydroelectric, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Stillwater?

Stillwater has a dam height of 25 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Stillwater last inspected?

Stillwater was last inspected on September 14, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.