Lower Long Lake
Key Takeaway
Lower Long Lake is classified as high hazard in Colorado. It was completed in 1939 and is 87 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 | 19 ft (taller than 32.7% in CO) |
| Dam Length | 1,350 ft |
| Dam Type | Earth |
| Max Storage | 409 acre-ft |
| Normal Storage | 292 acre-ft |
| Surface Area | 30 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 330 cfs |
| Year Completed | 1939 (87 years old) |
| NID ID | CO01784 |
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
DENVER BOARD OF WATER COMMISSIONERS
Public Utility
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What is the hazard classification of Lower Long Lake?
Lower Long Lake 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 Lower Long Lake?
Lower Long Lake is owned by DENVER BOARD OF WATER COMMISSIONERS (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Lower Long Lake built?
Lower Long Lake was completed in 1939, making it 87 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 Lower Long Lake?
Lower Long Lake 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 Lower Long Lake?
Lower Long Lake has a dam height of 19 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 Lower Long Lake last inspected?
Lower Long Lake was last inspected on June 8, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.