Mahinahina Reservoir
Key Takeaway
Mahinahina Reservoir is classified as high hazard in Hawaii. It was completed in 1995 and is 31 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 | 34 ft (taller than 47.2% in HI) |
| Dam Length | 630 ft |
| Dam Type | Earth |
| Max Storage | 73 acre-ft |
| Normal Storage | 61 acre-ft |
| Surface Area | 5 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 31 cfs |
| Year Completed | 1995 (31 years old) |
| NID ID | HI00144 |
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
Maui County, Dept of Water Supply
Local Government
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High Hazard 49 ftFrequently Asked Questions
What is the hazard classification of Mahinahina Reservoir?
Mahinahina 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 Mahinahina Reservoir?
Mahinahina Reservoir is owned by Maui County, Dept of Water Supply (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Mahinahina Reservoir built?
Mahinahina Reservoir was completed in 1995, making it 31 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 Mahinahina Reservoir?
Mahinahina Reservoir 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 Mahinahina Reservoir?
Mahinahina Reservoir has a dam height of 34 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 Mahinahina Reservoir last inspected?
Mahinahina Reservoir was last inspected on December 8, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.