Superior Dam
Superior Dam is an earth dam located in Washtenaw County, Michigan, built in 1919. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Superior Dam
The primary purpose of Superior Dam is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Ann Arbor, City Of (local government). It impounds the Huron River near Iypsilanti/belleville.
The dam stands 35 feet tall and stretches 496 feet across, creates a reservoir covering 103 acres, has a maximum storage capacity of 2,803 acre-feet, and collects water from a drainage area of 801 square miles. Completed in 1919, the structure is over a century old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 07/14/2022.
At 35 feet, this dam is taller than 82% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Michigan dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Michigan |
| County | Washtenaw |
| Nearest City | Iypsilanti/belleville |
| River/Stream | Huron River |
| Coordinates | 42.26550, -83.64420 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 35 ft |
| Dam Height | 25 ft |
| Dam Length | 496 ft |
| Year Completed | 1919 (107 years old) |
Storage & Hydraulics
| NID Storage | 2,803 acre-ft |
| Max Storage | 2,803 acre-ft |
| Normal Storage | 700 acre-ft |
| Surface Area | 103 acres |
| Drainage Area | 801 sq mi |
| Max Discharge | 17,200 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Ann Arbor, City of |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 07/14/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MI00558 |
| Federal ID | MI00558 |
| More Info | State Dam Safety Program |