Onion Head
Key Takeaway
Onion Head is classified as low hazard in Montana. It was completed in 1955 and is 71 years old. Its primary use is irrigation.
Physical Details
| Dam Height | 29 ft (taller than 82.2% in MT) |
| Dam Length | 1,300 ft |
| Dam Type | Earth |
| Max Storage | 374 acre-ft |
| Normal Storage | 239 acre-ft |
| Surface Area | 25 acres |
| Year Completed | 1955 (71 years old) |
| NID ID | MT03671 |
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
SPRINGDALE COLONY INC
Private
Nearby Dams
Screwed Up
Meagher, MT
Low Hazard 10 ftSpringdale
Meagher, MT
Low Hazard 20 ftSpringdale #3
Meagher, MT
Low Hazard 10 ftSpringdale Colony
Meagher, MT
Low Hazard 30 ftJackson Lake Dam
Meagher, MT
High Hazard 32 ftSpringdale #4
Meagher, MT
Low Hazard 26 ftHanson Reservoir Dam
Meagher, MT
Significant Hazard 13 ftSterret
Meagher, MT
Low Hazard 23 ftFrequently Asked Questions
What is the hazard classification of Onion Head?
Onion Head 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 Onion Head?
Onion Head is owned by SPRINGDALE COLONY INC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Onion Head built?
Onion Head was completed in 1955, making it 71 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 Onion Head?
Onion Head 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 Onion Head?
Onion Head has a dam height of 29 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.