Waikamoi Reservoirs
Waikamoi Reservoirs is an earth dam located in Maui County, Hawaii, built in 1980. It carries a Significant hazard potential classification and has a poor condition assessment.
About Waikamoi Reservoirs
The primary purpose of Waikamoi Reservoirs is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Maui County, Dept Of Water Supply (local government).
The dam stands 20 feet tall and stretches 921 feet across, creates a reservoir covering 3 acres, has a maximum storage capacity of 97 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1980, the structure is 46 years old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 06/05/2025.
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Location
| State | Hawaii |
| County | Maui |
| Nearest City | Kailua |
| Coordinates | 20.80902, -156.23259 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 20 ft |
| Dam Height | 20 ft |
| Dam Length | 921 ft |
| Year Completed | 1980 (46 years old) |
Storage & Hydraulics
| NID Storage | 97 acre-ft |
| Max Storage | 97 acre-ft |
| Normal Storage | 92 acre-ft |
| Surface Area | 3 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Maui County, Dept of Water Supply |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Poor |
| Last Inspection | 06/05/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | HI00152 |
| Federal ID | HI00152 |
| More Info | State Dam Safety Program |