Oahu is grappling with the worst flooding the state has seen in more than two decades after intense winter storms forced thousands to seek higher ground. The North Shore, known for its surf, has borne the brunt of the damage as heavy, muddy runoff swept across the island.
Torrents carried away cars and damaged homes, washed out roads and prompted the evacuation of at least 5,500 residents north of Honolulu. Governor Josh Green warned the event will have serious consequences for the state and said the flooding is the worst since 2004. He estimated combined public and private losses could top $1 billion (about €860 million). Honolulu Mayor Rick Blangiardi described the destruction as catastrophic.
Meteorologists point to Kona low systems, which regularly bring wet winter weather to Hawaii, and note that human-driven changes appear to be intensifying these storms. National Weather Service crews at Kaala, Oahu’s highest peak, measured about 16 inches (40 cm) of rain overnight Thursday; many other locations recorded 8 to 12 inches. The NWS has issued flood watches across the islands and flash flood warnings for the North Shore. Officials warned an additional 6 to 8 inches of rain could fall over the next two to three days.
There have been no reported fatalities so far. Officials said roughly 10 people were hospitalized with hypothermia. Rescue teams have pulled more than 230 people to safety, including about 70 children and adults airlifted from a Catholic youth camp by the National Guard and the Honolulu Fire Department. Authorities said some rescues were made more difficult when people flew drones over affected areas to capture images.
A major ongoing concern is the Wahiawa Dam, which officials have labeled high-hazard potential and say is at risk of imminent failure. They warned that a breach would likely result in loss of life. The earthen dam, originally built by Dole in 1906 and rebuilt after a 1921 collapse, was reported near capacity; its reservoir reached about 25.6 meters on Friday, roughly 1.8 meters below overflow after rising more than 1.5 meters overnight.
State officials have pressed Dole to address safety issues at Wahiawa since 2009. The company was fined $20,000 five years ago for not resolving some concerns. Dole has offered to donate the dam, reservoir and ditch system to the state if Hawaii agrees to repair the spillway to meet safety standards. Legislation authorizing the state’s acquisition passed in 2023, and a state board is scheduled to vote on the transfer next week. Dole said the dam continues to operate as designed and that crews have seen no indications of damage.
Hawaii oversees 132 dams, many originally constructed for sugar cane irrigation, according to the American Society of Civil Engineers.
Oahu’s Emergency Management Agency ordered about 4,000 residents downstream of Wahiawa Dam to evacuate immediately. On Saturday officials again urged evacuations across parts of the island and encouraged people to use emergency shelters set up by authorities and local groups as flash flooding remained occurring or imminent. Residents were asked to carpool where possible as roads became increasingly impassable.
Officials continue to monitor rainfall and dam conditions closely. Residents are advised to follow local emergency alerts, avoid flooded roads, and seek shelter if instructed by authorities.
Edited by Kieran Burke