Mottville
Mottville is a gravity dam located in St. Joseph County, Michigan, built in 1920. It carries a High hazard potential classification and has a fair condition assessment.
About Mottville
The primary purpose of Mottville 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 Indiana & Michigan Power Company (public utility). It impounds the St Joseph River near Mottville.
The dam stands 23 feet tall and stretches 846 feet across, creates a reservoir covering 378 acres, has a maximum storage capacity of 4,256 acre-feet, and collects water from a drainage area of 1,866 square miles. Completed in 1920, 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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 05/17/2022.
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 | St. Joseph |
| Nearest City | Mottville |
| River/Stream | St Joseph River |
| Coordinates | 41.80554, -85.74994 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 23 ft |
| Dam Height | 23 ft |
| Dam Length | 846 ft |
| Year Completed | 1920 (106 years old) |
Storage & Hydraulics
| NID Storage | 4,256 acre-ft |
| Max Storage | 4,256 acre-ft |
| Normal Storage | 4,256 acre-ft |
| Surface Area | 378 acres |
| Drainage Area | 1,866 sq mi |
| Max Discharge | 20,610 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Indiana & Michigan Power Company |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 05/17/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MI00187 |
| Federal ID | MI00187 |
| More Info | State Dam Safety Program |