Northern Pacific Reservoir Dam
Key Takeaway
Northern Pacific Reservoir Dam is classified as high hazard in Montana. It was completed in 1935 and is 91 years old. Its primary use is water supply. 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 | 35 ft (taller than 92.6% in MT) |
| Dam Length | 107 ft |
| Dam Type | Gravity |
| Max Storage | 173 acre-ft |
| Normal Storage | 48 acre-ft |
| Surface Area | 18 acres |
| Drainage Area | 34 sq mi |
| Max Discharge | 800 cfs |
| Year Completed | 1935 (91 years old) |
| NID ID | MT00858 |
Safety Information
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?
Ownership
ASH GROVE CEMENT
Private
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Northern Pacific Reservoir Dam?
Northern Pacific Reservoir 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 Northern Pacific Reservoir Dam?
Northern Pacific Reservoir Dam is owned by ASH GROVE CEMENT (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Northern Pacific Reservoir Dam built?
Northern Pacific Reservoir Dam was completed in 1935, making it 91 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 Northern Pacific Reservoir Dam?
Northern Pacific Reservoir Dam serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Northern Pacific Reservoir Dam?
Northern Pacific Reservoir Dam has a dam height of 35 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.