Manchester Mill Dam

River Raisin· Washtenaw, Michigan· Built 1908· Gravity· 18 ft tall
High Hazard Recreation Private

Key Takeaway

Manchester Mill Dam is classified as high hazard in Michigan. It was completed in 1908 and is 118 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 18 ft (taller than 63.6% in MI)
Dam Length82 ft
Dam TypeGravity
Max Storage210 acre-ft
Normal Storage58 acre-ft
Surface Area12 acres
Drainage Area144 sq mi
Max Discharge1,550 cfs
Year Completed1908 (118 years old)
NID IDMI00715

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: September 16, 2016
State Regulated: Yes
Regulatory Agency: MICHIGAN DEGLE

Ownership

Alwicz Holdings

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Manchester Mill Dam?

Manchester Mill 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 Manchester Mill Dam?

Manchester Mill Dam is owned by Alwicz Holdings (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Manchester Mill Dam built?

Manchester Mill Dam was completed in 1908, making it 118 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 Manchester Mill Dam?

Manchester Mill 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 Manchester Mill Dam?

Manchester Mill Dam has a dam height of 18 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 Manchester Mill Dam last inspected?

Manchester Mill Dam was last inspected on September 16, 2016. 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.