Granby #5-11
Key Takeaway
Granby #5-11 is classified as high hazard in Colorado. It was completed in 1930 and is 96 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 | 30 ft (taller than 65.6% in CO) |
| Dam Length | 3,400 ft |
| Dam Type | Earth |
| Max Storage | 1.1K acre-ft |
| Normal Storage | 775 acre-ft |
| Surface Area | 72 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 588 cfs |
| Year Completed | 1930 (96 years old) |
| Year Modified | 2002 |
| NID ID | CO00720 |
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
GRANBY DITCH & RESERVOIR CO. (THOMPSON, BRIAN)
Private
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Low Hazard 15 ftFrequently Asked Questions
What is the hazard classification of Granby #5-11?
Granby #5-11 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 Granby #5-11?
Granby #5-11 is owned by GRANBY DITCH & RESERVOIR CO. (THOMPSON, BRIAN) (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Granby #5-11 built?
Granby #5-11 was completed in 1930, making it 96 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 Granby #5-11?
Granby #5-11 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 Granby #5-11?
Granby #5-11 has a dam height of 30 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 Granby #5-11 last inspected?
Granby #5-11 was last inspected on July 28, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.