Jonas #2
Key Takeaway
Jonas #2 is classified as low hazard in Montana. It was completed in 1943 and is 83 years old. Its primary use is fire protection.
Physical Details
| Dam Height | 14 ft (taller than 15.6% in MT) |
| Dam Length | 100 ft |
| Dam Type | Earth |
| Max Storage | 57 acre-ft |
| Normal Storage | 11 acre-ft |
| Year Completed | 1943 (83 years old) |
| NID ID | MT02440 |
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
JOHN MAHLSTEDT
Private
Nearby Dams
Jensen Reservoir (Dawson)
Dawson, MT
Low Hazard 19 ftJensen No 3 (Dawson)
Dawson, MT
Low Hazard 15 ftJonas #1
Dawson, MT
Low Hazard 25 ftCircle Reservoir
Dawson, MT
Low Hazard 15 ftSnowfall
McCone, MT
Low Hazard 20 ftVoss #1
McCone, MT
Low Hazard 10 ftQuick, Floyd #2
McCone, MT
Low Hazard 15 ftJohnson Reservoir
Dawson, MT
Low Hazard 21 ftFrequently Asked Questions
What is the hazard classification of Jonas #2?
Jonas #2 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 Jonas #2?
Jonas #2 is owned by JOHN MAHLSTEDT (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Jonas #2 built?
Jonas #2 was completed in 1943, making it 83 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 Jonas #2?
Jonas #2 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 Jonas #2?
Jonas #2 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.