Deer Flat Lower
Key Takeaway
Deer Flat Lower is classified as high hazard in Idaho. It was completed in 1907 and is 119 years old. Its primary use is irrigation. 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 | 48 ft (taller than 77.9% in ID) |
| Dam Length | 7,270 ft |
| Dam Type | Earth |
| Max Storage | 159.4K acre-ft |
| Surface Area | 10,100 acres |
| Drainage Area | 92 sq mi |
| Max Discharge | 1,270 cfs |
| Year Completed | 1907 (119 years old) |
| Year Modified | 1991 |
| NID ID | ID00278 |
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
RECLAMATION
Federal Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Deer Flat Lower?
Deer Flat Lower 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 Deer Flat Lower?
Deer Flat Lower is owned by RECLAMATION (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Deer Flat Lower built?
Deer Flat Lower was completed in 1907, making it 119 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 Deer Flat Lower?
Deer Flat Lower serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Deer Flat Lower?
Deer Flat Lower has a dam height of 48 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 Deer Flat Lower last inspected?
Deer Flat Lower was last inspected on August 11, 2020. Inspection dates indicate when a formal review occurred, not the results of that inspection.