Waikoloa Reservoir No. 1
Key Takeaway
Waikoloa Reservoir No. 1 is classified as high hazard in Hawaii. It was completed in 1970 and is 56 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 | 44 ft (taller than 73.2% in HI) |
| Dam Length | 1,700 ft |
| Dam Type | Earth |
| Max Storage | 190 acre-ft |
| Normal Storage | 157 acre-ft |
| Surface Area | 7 acres |
| Max Discharge | 160 cfs |
| Year Completed | 1970 (56 years old) |
| NID ID | HI00040 |
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 County, Dept of Water Supply
Local Government
Nearby Dams
Waikoloa Reservoir No. 2
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High Hazard 38 ftFrequently Asked Questions
What is the hazard classification of Waikoloa Reservoir No. 1?
Waikoloa Reservoir No. 1 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 Waikoloa Reservoir No. 1?
Waikoloa Reservoir No. 1 is owned by Hawaii County, Dept of Water Supply (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Waikoloa Reservoir No. 1 built?
Waikoloa Reservoir No. 1 was completed in 1970, making it 56 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 Waikoloa Reservoir No. 1?
Waikoloa Reservoir No. 1 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 Waikoloa Reservoir No. 1?
Waikoloa Reservoir No. 1 has a dam height of 44 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 Waikoloa Reservoir No. 1 last inspected?
Waikoloa Reservoir No. 1 was last inspected on April 28, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.