Thompson Falls - Main Channel Dam
Key Takeaway
Thompson Falls - Main Channel Dam is classified as low hazard in Montana. It was completed in 1915 and is 111 years old. Its primary use is hydroelectric.
Physical Details
| Dam Height | 50 ft (taller than 96.8% in MT) |
| Dam Length | 1,016 ft |
| Dam Type | Gravity |
| Max Storage | 24.5K acre-ft |
| Normal Storage | 15.0K acre-ft |
| Surface Area | 1,580 acres |
| Drainage Area | 21,113 sq mi |
| Max Discharge | 175,000 cfs |
| Year Completed | 1915 (111 years old) |
| NID ID | MT00224 |
Safety Information
No probable loss of human life and low economic/environmental losses expected.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
NorthWestern Energy
Private
Frequently Asked Questions
What is the hazard classification of Thompson Falls - Main Channel Dam?
Thompson Falls - Main Channel Dam is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Thompson Falls - Main Channel Dam?
Thompson Falls - Main Channel Dam is owned by NorthWestern Energy (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Thompson Falls - Main Channel Dam built?
Thompson Falls - Main Channel Dam was completed in 1915, making it 111 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 Thompson Falls - Main Channel Dam?
Thompson Falls - Main Channel Dam serves the following purposes: Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Thompson Falls - Main Channel Dam?
Thompson Falls - Main Channel Dam has a dam height of 50 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 Thompson Falls - Main Channel Dam last inspected?
Thompson Falls - Main Channel Dam was last inspected on August 31, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.