Thomson Canal Dam
Thomson Canal Dam is a dam located in Carlton County, Minnesota, built in 1907. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Thomson Canal Dam
The primary purpose of Thomson Canal 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 Allete, Inc. (private). It impounds the St. Louis River near Duluth.
The dam stands 45 feet tall and stretches 3,500 feet across, creates a reservoir covering 375 acres, and has a maximum storage capacity of 4,352 acre-feet. Completed in 1907, 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 09/21/2021.
At 45 feet, this dam is taller than 91% 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 Minnesota 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 | Minnesota |
| County | Carlton |
| Nearest City | Duluth |
| River/Stream | St. Louis River |
| Coordinates | 46.66088, -92.35083 |
Physical Characteristics
| NID Height | 45 ft |
| Dam Height | 45 ft |
| Dam Length | 3,500 ft |
| Year Completed | 1907 (119 years old) |
Storage & Hydraulics
| NID Storage | 4,352 acre-ft |
| Max Storage | 4,352 acre-ft |
| Normal Storage | 4,352 acre-ft |
| Surface Area | 375 acres |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Allete, Inc. |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/21/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MN00604 |
| Federal ID | MN00604S011 |
| More Info | State Dam Safety Program |