Upper Twin Lakes
Key Takeaway
Upper Twin Lakes is classified as low hazard in Montana. It was completed in 1964 and is 62 years old. Its primary use is irrigation.
Physical Details
| Dam Height | 14 ft (taller than 15.6% in MT) |
| Dam Length | 450 ft |
| Dam Type | Earth |
| Normal Storage | 220 acre-ft |
| Surface Area | 31 acres |
| Drainage Area | 1 sq mi |
| Year Completed | 1964 (62 years old) |
| NID ID | MT01166 |
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
CHARLOS IRRIGATION DISTRICT
Local Government
Nearby Dams
Lower Twin Lakes
Ravalli, MT
Low Hazard 20 ftUpper Bear Dam
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Low Hazard 26 ftBlodgett Lake
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Low Hazard 14 ftMill Lake
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High Hazard 25 ftHigh Lake
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High Hazard 30 ftWyant Lake
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Low Hazard 18 ftSears
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Low Hazard 10 ftFrequently Asked Questions
What is the hazard classification of Upper Twin Lakes?
Upper Twin Lakes 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 Upper Twin Lakes?
Upper Twin Lakes is owned by CHARLOS IRRIGATION DISTRICT (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Upper Twin Lakes built?
Upper Twin Lakes was completed in 1964, making it 62 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 Upper Twin Lakes?
Upper Twin Lakes 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 Upper Twin Lakes?
Upper Twin Lakes has a dam height of 14 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 Upper Twin Lakes last inspected?
Upper Twin Lakes was last inspected on August 1, 1989. Inspection dates indicate when a formal review occurred, not the results of that inspection.