Johnston City Lake Dam
Key Takeaway
Johnston City Lake Dam is classified as significant hazard in Illinois. It was completed in 1921 and is 105 years old. Its primary use is water supply. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Height | 14 ft (taller than 14.5% in IL) |
| Dam Length | 855 ft |
| Dam Type | Earth |
| Max Storage | 601 acre-ft |
| Normal Storage | 466 acre-ft |
| Year Completed | 1921 (105 years old) |
| NID ID | IL00048 |
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
CITY OF JOHNSON CITY
Local Government
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What is the hazard classification of Johnston City Lake Dam?
Johnston City Lake Dam 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 Johnston City Lake Dam?
Johnston City Lake Dam is owned by CITY OF JOHNSON CITY (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Johnston City Lake Dam built?
Johnston City Lake Dam was completed in 1921, making it 105 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 Johnston City Lake Dam?
Johnston City Lake Dam 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 Johnston City Lake Dam?
Johnston City Lake Dam 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 Johnston City Lake Dam last inspected?
Johnston City Lake Dam was last inspected on May 10, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.