Allegheny River Lock and Dam 4
Key Takeaway
Allegheny River Lock and Dam 4 is classified as significant hazard in Pennsylvania. It was completed in 1927 and is 99 years old. Its primary use is navigation. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Length | 954 ft |
| Dam Type | Gravity |
| Max Storage | 9.0K acre-ft |
| Normal Storage | 9.0K acre-ft |
| Surface Area | 710 acres |
| Drainage Area | 11,419 sq mi |
| Max Discharge | 140,000 cfs |
| Year Completed | 1927 (99 years old) |
| NID ID | PA00114 |
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
USACE - Pittsburgh District
Federal Government
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Low Hazard 153 ftFrequently Asked Questions
What is the hazard classification of Allegheny River Lock and Dam 4?
Allegheny River Lock and Dam 4 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 Allegheny River Lock and Dam 4?
Allegheny River Lock and Dam 4 is owned by USACE - Pittsburgh District (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Allegheny River Lock and Dam 4 built?
Allegheny River Lock and Dam 4 was completed in 1927, making it 99 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 Allegheny River Lock and Dam 4?
Allegheny River Lock and Dam 4 serves the following purposes: Navigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
When was Allegheny River Lock and Dam 4 last inspected?
Allegheny River Lock and Dam 4 was last inspected on October 26, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.