DLNR News Release – NR – WAHIAWĀ DAM REHABILITATION PROJECT BEGINS WITH A BLESSING

STATE OF HAWAIʻI

KA MOKU ʻĀINA O HAWAIʻI

JOSH GREEN, M.D.

GOVERNOR

KE KIAʻĀINA

DEPARTMENT OF LAND AND NATURAL RESOURCES

KA ‘OIHANA KUMUWAIWAI ‘ĀINA

RYAN KANAKA‘OLE

ACTING CHAIRPERSON 

WAHIAWĀ DAM REHABILITATION PROJECT BEGINS WITH A BLESSING

FOR IMMEDIATE RELEASE 

May 11, 2026 

HONOLULU – The Wahiawā Dam Rehabilitation Project officially began today with a blessing by Kahu Kordell Kekoa at the at Wahiawā State Freshwater Park. The kahu joined in the ceremony led by Governor Josh Green, members of the State Senate and House of Representatives, along with officials from the Hawaiʻi Department of Agriculture and Biosecurity (DAB), Department of Transportation (HDOT), Department of Business, Economic Development and Tourism (DBEDT), Agribusiness Development Corporation (ADC), Department of Land and Natural Resources (DLNR), the Hawaiʻi Emergency Management Agency (HIEMA), as well as representatives from Dole Food Company.

“We went through the March and April storms together and let’s just be blunt, it was scary,” said Governor Green. “As the water was rising, you had thousands of people who were aware that it was an existential problem for them if the dam couldn’t make it. 

“There were moments in the middle of the night when Mayor Blangiardi and I were wondering, ‘Will this hold?’ and we can’t have that question any longer, so it’s up to us to be good partners and that’s what we’ll do. And so, we’ve been working with Dole, we’ve been working with everyone to make sure we’re safer going forward,” he added.   

The project will address critical safety concerns by bringing the dam and spillway into compliance with all relevant safety requirements. Rehabilitation work includes improvements to the dam embankment and modifications to the spillway to increase discharge capacity.

The new spillway design by GFT Infrastructure, Inc. (formerly Gannett Fleming and TranSystems) will be the first sawtooth spillway design, also known as a labyrinth spillway, to be constructed on any dam in Hawaiʻi. The design will effectively expand the spillway six times its current width, within the footprint of the existing structure.

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

“In recent years, we’ve seen a concerning trend as an increasing number of private landowners have sought permits to remove their dams,” said DLNR Acting Chairperson Ryan Kanaka‘ole. “This has resulted in a substantial decline in Hawaiʻi’s freshwater resources at a time when periods of drought have become far more common.”

Kanaka‘ole further noted, “When rehabilitation of the Wahiawā Dam is complete, this reservoir will continue to support groundwater recharge, irrigation and agricultural resilience, wildfire response, habitat for wildlife and future recreational opportunities for our communities.”

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.

The transfer of all properties authorized to be acquired by Act 218 must be recorded with the DLNR Bureau of Conveyances by June 30, 2026, for the state to take ownership of the Wahiawā Irrigation System, dam and spillway.

Wahiawā Dam Rehabilitation Project Details

• Purpose: Emergency dam repairs and upgrades

• Project lead: Hawai‘i Department of Agriculture and Biosecurity

• Project support: Hawai‘i Department of Transportation

• Estimated cost: $65 million

• Funding source: State funds

• Design: GFT Infrastructure, Inc.

• Construction: Goodfellow Bros. LLC

• Estimated project time: 18 months

• The new design will pass more water safely through the spillway and protect the dam from overtopping in a probable maximum storm which is a storm that greatly exceeds the hundred-year event.

• The sawtooth weir will provide a wider area for water to be channeled through, while occupying the same footprint of the current spillway.

• Improvements will enable 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.

• At the end of construction, the DLNR Division of Aquatic Resources will assess the fish population and determine if fishery improvements are needed to increase the number of fish in the lake.

• The Wahiawā Reservoir (Lake Wilson) will be managed by the DLNR Division of State Parks.

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