John Ball Reservoir
Key Takeaway
John Ball Reservoir is classified as significant hazard in Montana. It was completed in 1935 and is 91 years old. Its primary use is fire protection. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Height | 16 ft (taller than 31.7% in MT) |
| Dam Length | 360 ft |
| Dam Type | Earth |
| Max Storage | 145 acre-ft |
| Normal Storage | 61 acre-ft |
| Drainage Area | 1 sq mi |
| Max Discharge | 1,000 cfs |
| Year Completed | 1935 (91 years old) |
| NID ID | MT00482 |
Safety Information
No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
LYLE E NELSON
Private
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Low Hazard 20 ftFrequently Asked Questions
What is the hazard classification of John Ball Reservoir?
John Ball Reservoir is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates John Ball Reservoir?
John Ball Reservoir is owned by LYLE E NELSON (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was John Ball Reservoir built?
John Ball Reservoir 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 John Ball Reservoir?
John Ball Reservoir serves the following purposes: Fire Protection, Stock, Or Small Fish Pond. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is John Ball Reservoir?
John Ball Reservoir has a dam height of 16 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.