Geddes Dam

Huron River· Washtenaw, Michigan· Built 1920· Earth· 28 ft tall
High Hazard Recreation Local Government

Key Takeaway

Geddes Dam is classified as high hazard in Michigan. It was completed in 1920 and is 106 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 28 ft (taller than 87.5% in MI)
Dam Length274 ft
Dam TypeEarth
Max Storage3.1K acre-ft
Normal Storage4.3K acre-ft
Surface Area261 acres
Drainage Area765 sq mi
Max Discharge14,400 cfs
Year Completed1920 (106 years old)
NID IDMI00561

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: July 31, 2019
State Regulated: Yes
Regulatory Agency: MICHIGAN DEGLE

Ownership

City of Ann Arbor

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Geddes Dam?

Geddes 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 Geddes Dam?

Geddes Dam is owned by City of Ann Arbor (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Geddes Dam built?

Geddes Dam was completed in 1920, making it 106 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 Geddes Dam?

Geddes 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 Geddes Dam?

Geddes Dam has a dam height of 28 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 Geddes Dam last inspected?

Geddes Dam was last inspected on July 31, 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.