Siena
Key Takeaway
Siena is classified as high hazard in Colorado. It was completed in 2004 and is 22 years old. Its primary use is water supply. 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 | 40 ft (taller than 81.3% in CO) |
| Dam Length | 1,250 ft |
| Dam Type | Earth |
| Max Storage | 640 acre-ft |
| Normal Storage | 450 acre-ft |
| Surface Area | 20 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 690 cfs |
| Year Completed | 2004 (22 years old) |
| NID ID | CO02859 |
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
CITY OF BROOMFIELD (MIDDLETON, BRENNAN)
Local Government
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High Hazard 6 ftFrequently Asked Questions
What is the hazard classification of Siena?
Siena 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 Siena?
Siena is owned by CITY OF BROOMFIELD (MIDDLETON, BRENNAN) (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Siena built?
Siena was completed in 2004, making it 22 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 Siena?
Siena serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Siena?
Siena has a dam height of 40 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 Siena last inspected?
Siena was last inspected on May 3, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.