Waita Reservoir
Waita Reservoir is an earth dam located in Kauai County, Hawaii, built in 1906. It carries a High hazard potential classification and has a poor condition assessment.
About Waita Reservoir
The primary purpose of Waita Reservoir is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Grove Farm Company (private). It impounds the Waihohonu Stream Offstream near Koloa.
The dam stands 28 feet tall and stretches 3,250 feet across, creates a reservoir covering 650 acres, has a maximum storage capacity of 9,900 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1906, the structure is over a century 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 07/17/2025.
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 | Koloa |
| River/Stream | Waihohonu Stream Offstream |
| Coordinates | 21.91066, -159.45310 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 28 ft |
| Dam Height | 23 ft |
| Dam Length | 3,250 ft |
| Year Completed | 1906 (120 years old) |
Storage & Hydraulics
| NID Storage | 9,900 acre-ft |
| Max Storage | 9,900 acre-ft |
| Normal Storage | 3,400 acre-ft |
| Surface Area | 650 acres |
| Drainage Area | 3 sq mi |
| Max Discharge | 2,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Grove Farm Company |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 07/17/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | HI00099 |
| Federal ID | HI00099 |
| More Info | State Dam Safety Program |