Mana Reservoir
Key Takeaway
Mana Reservoir is classified as high hazard in Hawaii. It was completed in 1905 and is 121 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 | 17 ft (taller than 7.1% in HI) |
| Dam Length | 1,730 ft |
| Dam Type | Earth |
| Max Storage | 135 acre-ft |
| Normal Storage | 135 acre-ft |
| Surface Area | 9 acres |
| Drainage Area | 0 sq mi |
| Year Completed | 1905 (121 years old) |
| NID ID | HI00005 |
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
Hawaii Dept of Agriculture - ADC
State Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Mana Reservoir?
Mana Reservoir 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 Mana Reservoir?
Mana Reservoir is owned by Hawaii Dept of Agriculture - ADC (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Mana Reservoir built?
Mana Reservoir was completed in 1905, making it 121 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 Mana Reservoir?
Mana Reservoir 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 Mana Reservoir?
Mana Reservoir has a dam height of 17 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 Mana Reservoir last inspected?
Mana Reservoir was last inspected on November 16, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.