Ioleau Reservoir
Ioleau Reservoir is an earth dam located in Kauai County, Hawaii, built in 1902. It carries a Low hazard potential classification and has a poor condition assessment.
About Ioleau Reservoir
The primary purpose of Ioleau Reservoir is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Bbcp Kauai Operating, Llc, Kauai Coffee (private). It impounds the Fed By Irrigation Ditch near Kalaheo.
The dam stands 48 feet tall and stretches 980 feet across, creates a reservoir covering 6 acres, has a maximum storage capacity of 148 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1902, the structure is over a century old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected 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 05/20/2025.
At 48 feet, this dam is taller than 92% of dams nationwide.
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Location
| State | Hawaii |
| County | Kauai |
| Nearest City | Kalaheo |
| River/Stream | Fed By Irrigation Ditch |
| Coordinates | 21.90003, -159.53451 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 48 ft |
| Dam Height | 48 ft |
| Dam Length | 980 ft |
| Year Completed | 1902 (124 years old) |
Storage & Hydraulics
| NID Storage | 148 acre-ft |
| Max Storage | 148 acre-ft |
| Normal Storage | 107 acre-ft |
| Surface Area | 6 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | BBCP Kauai Operating, LLC, Kauai Coffee |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Poor |
| Last Inspection | 05/20/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | HI00102 |
| Federal ID | HI00102 |
| More Info | State Dam Safety Program |