Upper South Dam

Thunder Bay· Alpena, Michigan· Built 1930· Gravity· 20 ft tall
Low Hazard Hydroelectric Recreation Not Listed

Key Takeaway

Upper South Dam is classified as low hazard in Michigan. It was completed in 1930 and is 96 years old. Its primary use is hydroelectric.

Physical Details

Dam Height 20 ft (taller than 70.3% in MI)
Dam Length350 ft
Dam TypeGravity
Max Storage55.0K acre-ft
Normal Storage40.1K acre-ft
Surface Area7,000 acres
Drainage Area182 sq mi
Max Discharge4,850 cfs
Year Completed1930 (96 years old)
NID IDMI00202

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 17, 2019
State Regulated: No

Ownership

Not Listed

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Upper South Dam?

Upper South Dam 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 Upper South Dam?

Upper South Dam is owned by information not available (Not Listed). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Upper South Dam built?

Upper South Dam was completed in 1930, making it 96 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 Upper South Dam?

Upper South Dam 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 Upper South Dam?

Upper South Dam has a dam height of 20 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 Upper South Dam last inspected?

Upper South Dam was last inspected on September 17, 2019. 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.