Upper Big Nemaha J-12a
Key Takeaway
Upper Big Nemaha J-12a is classified as low hazard in Nebraska. It was completed in 1973 and is 53 years old. Its primary use is other.
Physical Details
| Dam Height | 26 ft (taller than 50.7% in NE) |
| Dam Length | 570 ft |
| Dam Type | Earth |
| Max Storage | 147 acre-ft |
| Normal Storage | 29 acre-ft |
| Surface Area | 8 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 787 cfs |
| Year Completed | 1973 (53 years old) |
| NID ID | NE00640 |
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
Nemaha Natural Resources District
Local Government
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Low Hazard 26 ftFrequently Asked Questions
What is the hazard classification of Upper Big Nemaha J-12a?
Upper Big Nemaha J-12a 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 Upper Big Nemaha J-12a?
Upper Big Nemaha J-12a is owned by Nemaha Natural Resources District (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Upper Big Nemaha J-12a built?
Upper Big Nemaha J-12a was completed in 1973, making it 53 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 Upper Big Nemaha J-12a?
Upper Big Nemaha J-12a serves the following purposes: Other, Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Upper Big Nemaha J-12a?
Upper Big Nemaha J-12a has a dam height of 26 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 Upper Big Nemaha J-12a last inspected?
Upper Big Nemaha J-12a was last inspected on May 24, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.