Kahana Nui Dam
Kahana Nui Dam is an earth dam located in Maui County, Hawaii, built in 1984. It carries a High hazard potential classification and has a poor condition assessment.
About Kahana Nui Dam
The primary purpose of Kahana Nui Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Maui County, Dept Of Public Works (local government). It impounds the Kahana Stream near Kahana.
The dam stands 58 feet tall and stretches 500 feet across, creates a reservoir covering 5 acres, has a maximum storage capacity of 225 acre-feet, and collects water from a drainage area of 4 square miles. Completed in 1984, the structure is 42 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. 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 04/17/2025.
At 58 feet, this dam is taller than 95% of all dams in the United States.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Hawaii dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Hawaii |
| County | Maui |
| Nearest City | Kahana |
| River/Stream | Kahana Stream |
| Coordinates | 20.97605, -156.67238 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 58 ft |
| Dam Height | 49 ft |
| Dam Length | 500 ft |
| Year Completed | 1984 (42 years old) |
Storage & Hydraulics
| NID Storage | 225 acre-ft |
| Max Storage | 225 acre-ft |
| Normal Storage | 59 acre-ft |
| Surface Area | 5 acres |
| Drainage Area | 4 sq mi |
| Max Discharge | 25,884 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Maui County, Dept of Public Works |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 04/17/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | HI00126 |
| Federal ID | HI00126 |
| More Info | State Dam Safety Program |