Johnstown
Key Takeaway
Johnstown is classified as high hazard in Colorado. It was completed in 1925 and is 101 years old. Its primary use is water supply. 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 | 19 ft (taller than 32.7% in CO) |
| Dam Length | 5,737 ft |
| Dam Type | Earth |
| Max Storage | 430 acre-ft |
| Normal Storage | 324 acre-ft |
| Surface Area | 35 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 294 cfs |
| Year Completed | 1925 (101 years old) |
| Year Modified | 2022 |
| NID ID | CO01772 |
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
TOWN OF JOHNSTOWN
Local Government
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Significant Hazard 38 ftFrequently Asked Questions
What is the hazard classification of Johnstown?
Johnstown 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 Johnstown?
Johnstown is owned by TOWN OF JOHNSTOWN (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Johnstown built?
Johnstown was completed in 1925, making it 101 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 Johnstown?
Johnstown serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Johnstown?
Johnstown has a dam height of 19 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 Johnstown last inspected?
Johnstown was last inspected on May 19, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.