Waikoloi Reservoir
Waikoloi Reservoir is an earth dam located in Kauai County, Hawaii, built in 1958. It carries a High hazard potential classification and has a poor condition assessment.
About Waikoloi Reservoir
The primary purpose of Waikoloi Reservoir is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Robinson Family Partners (private). It impounds the Waikoloi Stream near Kaawanui Village.
The dam stands 64 feet tall and stretches 505 feet across, creates a reservoir covering 5 acres, has a maximum storage capacity of 147 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1958, the structure is well into its service life at over 50 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 10/22/2024.
At 64 feet, this dam is taller than 96% 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 | Kauai |
| Nearest City | Kaawanui Village |
| River/Stream | Waikoloi Stream |
| Coordinates | 21.97004, -159.59952 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 64 ft |
| Dam Height | 64 ft |
| Dam Length | 505 ft |
| Year Completed | 1958 (68 years old) |
Storage & Hydraulics
| NID Storage | 147 acre-ft |
| Max Storage | 147 acre-ft |
| Normal Storage | 130 acre-ft |
| Surface Area | 5 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Robinson Family Partners |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 10/22/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | HI00008 |
| Federal ID | HI00008 |
| More Info | State Dam Safety Program |