Portage Plant Dam

Portage River· St. Joseph, Michigan· Built 1922· Earth· 19 ft tall
High Hazard Recreation Private

Key Takeaway

Portage Plant Dam is classified as high hazard in Michigan. It was completed in 1922 and is 104 years old. Its primary use is recreation. 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 19 ft (taller than 67.3% in MI)
Dam Length1,116 ft
Dam TypeEarth
Max Storage1.3K acre-ft
Normal Storage900 acre-ft
Surface Area81 acres
Drainage Area192 sq mi
Max Discharge7,734 cfs
Year Completed1922 (104 years old)
NID IDMI00374

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: December 2, 2021
State Regulated: Yes
Regulatory Agency: MICHIGAN DEGLE

Ownership

Portage Power Company

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Portage Plant Dam?

Portage Plant Dam 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 Portage Plant Dam?

Portage Plant Dam is owned by Portage Power Company (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Portage Plant Dam built?

Portage Plant Dam was completed in 1922, making it 104 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 Portage Plant Dam?

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

How tall is Portage Plant Dam?

Portage Plant Dam has a dam height of 19 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 Portage Plant Dam last inspected?

Portage Plant Dam was last inspected on December 2, 2021. 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.