Mill Lake
Key Takeaway
Mill Lake is classified as high hazard in Montana. It was completed in 1895 and is 131 years old. Its primary use is irrigation. 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 | 25 ft (taller than 70.3% in MT) |
| Dam Length | 400 ft |
| Dam Type | Earth |
| Normal Storage | 670 acre-ft |
| Surface Area | 42 acres |
| Drainage Area | 1 sq mi |
| Year Completed | 1895 (131 years old) |
| Year Modified | 2003 |
| NID ID | MT01219 |
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
MILL CREEK IRR.
Private
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Low Hazard 14 ftFrequently Asked Questions
What is the hazard classification of Mill Lake?
Mill Lake 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 Mill Lake?
Mill Lake is owned by MILL CREEK IRR. (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Mill Lake built?
Mill Lake was completed in 1895, making it 131 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 Mill Lake?
Mill Lake serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Mill Lake?
Mill Lake has a dam height of 25 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.