Lower Kapahi Reservoir
Lower Kapahi Reservoir is an earth dam located in Kauai County, Hawaii, built in 1861. It carries a High hazard potential classification and has a unsatisfactory condition assessment.
About Lower Kapahi Reservoir
Lower Kapahi Reservoir is a dam in Kauai, Hawaii. The dam is owned by County Of Kauai - Department Of Public Works, Hawaii Dept Of Land & Natural Resources (local government). It impounds the Tr-kapaa Stream Offstream near Kawaihau.
The dam stands 24 feet tall and stretches 650 feet across, has a maximum storage capacity of 194 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1861, the structure is one of the older dams in the region, with over a century and a half of service.
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 unsatisfactory, indicating serious safety deficiencies exist that require immediate attention or remedial action. An emergency action plan is in place for this dam. The most recent inspection on record was 08/14/2025.
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 | Kauai |
| Nearest City | Kawaihau |
| River/Stream | Tr-kapaa Stream Offstream |
| Coordinates | 22.10159, -159.35282 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 24 ft |
| Dam Height | 20 ft |
| Dam Length | 650 ft |
| Year Completed | 1861 (165 years old) |
Storage & Hydraulics
| NID Storage | 194 acre-ft |
| Max Storage | 194 acre-ft |
| Normal Storage | 144 acre-ft |
| Drainage Area | 0 sq mi |
| Spillway Type | None |
Ownership & Safety
| Purpose | Other |
| Owner | County of Kauai - Department of Public Works, Hawaii Dept of Land & Natural Resources |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Unsatisfactory |
| Last Inspection | 08/14/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | HI00061 |
| Federal ID | HI00061 |
| More Info | State Dam Safety Program |