Ninth Street

Thunder Bay· Alpena, Michigan· Built 1910· Gravity· 24 ft tall
High Hazard Hydroelectric Recreation Private

Key Takeaway

Ninth Street is classified as high hazard in Michigan. It was completed in 1910 and is 116 years old. Its primary use is hydroelectric. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height 24 ft (taller than 81.6% in MI)
Dam Length1,340 ft
Dam TypeGravity
Max Storage6.0K acre-ft
Normal Storage6.0K acre-ft
Surface Area700 acres
Drainage Area1,275 sq mi
Max Discharge20,593 cfs
Year Completed1910 (116 years old)
NID IDMI00188

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

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

Emergency Action Plan: Yes
Last Inspection: August 24, 2022
State Regulated: No

Ownership

Eagle Creek Renewable Energies, LLC Parent Org (CRO)

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Ninth Street?

Ninth Street is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Ninth Street?

Ninth Street is owned by Eagle Creek Renewable Energies, LLC Parent Org (CRO) (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Ninth Street built?

Ninth Street was completed in 1910, making it 116 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 Ninth Street?

Ninth Street 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 Ninth Street?

Ninth Street has a dam height of 24 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 Ninth Street last inspected?

Ninth Street was last inspected on August 24, 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.