Mississippi River Lock and Dam 21
Key Takeaway
Mississippi River Lock and Dam 21 is classified as significant hazard in Missouri. It was completed in 1938 and is 88 years old. Its primary use is navigation. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Length | 3,116 ft |
| Dam Type | Concrete |
| Max Storage | 62.0K acre-ft |
| Normal Storage | 0 acre-ft |
| Surface Area | 8,843 acres |
| Drainage Area | 135,000 sq mi |
| Max Discharge | 529,000 cfs |
| Year Completed | 1938 (88 years old) |
| NID ID | MO10304 |
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 - Rock Island District
Federal Government
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Low Hazard 59 ftFrequently Asked Questions
What is the hazard classification of Mississippi River Lock and Dam 21?
Mississippi River Lock and Dam 21 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 Mississippi River Lock and Dam 21?
Mississippi River Lock and Dam 21 is owned by USACE - Rock Island District (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Mississippi River Lock and Dam 21 built?
Mississippi River Lock and Dam 21 was completed in 1938, making it 88 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 Mississippi River Lock and Dam 21?
Mississippi River Lock and Dam 21 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 Mississippi River Lock and Dam 21 last inspected?
Mississippi River Lock and Dam 21 was last inspected on July 27, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.