Wahiawā Dam Rehabilitation Project Begins With A Blessing

The Wahiawā Dam Rehabilitation Project officially began May 11, 2026, with a blessing by Kahu Kordell Kekoa at the Wahiawā State Freshwater Park, alongside Governor Green, government officials and representatives of private-sector stakeholders.

The project will address critical concerns by bringing the dam and spillway into compliance with all relevant safety requirements. The new spillway will be the first sawtooth weir design to be constructed on any dam in Hawaiʻi. It will effectively expand the spillway to six times its current width, within the footprint of the existing structure.

Once complete, more water will be able to safely pass through the spillway and protect the dam from overtopping in a probable maximum storm, which is a storm that greatly exceeds a 100-year event. The improvements will also provide capacity for more water to be safely stored in the reservoir, from the 65-foot depth that is currently maintained, to approximately 78 feet, providing more water for farmers, fishers and wildlife.

During construction, the state will prioritize water supply to current users of the Wahiawā Irrigation System, provided that it can be done safely.

The start of construction is the latest step in the implementation of Act 218, passed by the Hawaiʻi State Legislature and enacted by Governor Green in 2023. It authorizes the state to acquire the Wahiawā Irrigation System, on terms negotiated and agreed upon by the Office of the Governor, or by eminent domain - and to purchase, repair and maintain the associated spillway.