Hawaii’s Worst Flooding in 20 Years Overwhelms Oahu’s North Shore as Wahiawa Dam Monitored for Possible Failure
Heavy rains — up to nearly 16 inches at Oahu’s Kaala peak and 8–12 inches overnight across the North Shore — have produced Hawaii’s worst flooding in about 20 years, prompting evacuation orders for more than 4,000 people (officials say as many as 5,500 north of Honolulu), activation of the National Guard, flooded shelters and search-and-rescue operations using jet skis and airlifts. Authorities are closely monitoring the 120‑year‑old Wahiawa Dam after water ran over the spillway and warned it was "at risk of imminent failure" as more rain is forecast and crews contend with homes swept from foundations and rescue flights impeded by civilian drones.
📌 Key Facts
- At 5:35 a.m. officials issued an evacuation order for people downstream of the 120‑year‑old Wahiawa Dam — covering more than 4,000 people — and authorities overall reported roughly 5,500 people under evacuation orders north of Honolulu; officials warned the dam was "at risk of imminent failure" and that water was actively running over the spillway.
- Oahu saw extreme rainfall — Kaala peak received nearly 16 inches in a day, many areas had 8–12 inches overnight — and the National Weather Service warned of "widespread life‑threatening flash flooding" (especially in Haleiwa and Waialua); an additional 6–8 inches were forecast over the next two to three days.
- The Wahiawa Dam’s level rose from about 79 to 84 feet overnight (roughly 6 feet below its maximum) before receding somewhat; officials continued to closely monitor the dam for possible failure as more rain was expected.
- Floodwaters and mud pushed homes off foundations, swallowed vehicles and swept away some houses; shelters flooded — Waialua High and Intermediate School required relocating roughly 185 people and 50 pets by bus after the shelter itself flooded.
- Search-and-rescue and response operations were large-scale: firefighters and lifeguards on jet skis searched floodwaters for stranded people, the Hawaii National Guard was activated, and the Guard and Honolulu Fire Department airlifted 72 children and adults from the Our Lady of Kea’au spring break youth camp as a precaution.
- Officials described chest‑high floodwaters in parts of northern Oahu that left some residents effectively isolated and unable to evacuate; at least about 10 people were taken to hospitals for hypothermia and authorities reported no deaths or missing persons so far.
- Gov. Josh Green called the event Hawaii’s most serious flooding since the 2004 Manoa floods and estimated total storm costs could top $1 billion, citing damage to airports, schools, roads, homes and a hospital on Maui.
- Search-and-rescue efforts were hampered by civilians flying personal drones over the flood zone, which interfered with aerial operations.
📊 Relevant Data
In Hawaii, Native Hawaiian and Pacific Islander residents make up 15.4% of the population in the North Shore area of Oahu, compared to approximately 10% statewide, potentially contributing to higher vulnerability in flood-affected regions.
Oahu's North Shore Profile Report — State of Hawaii Department of Business, Economic Development & Tourism
Native Americans, including groups like Native Hawaiians, are more exposed to flood risk than other racial groups in the United States, while Black and Asian communities are less exposed than predominantly White areas.
The Racial Dynamics Involved in Flood Risk Aren't What You'd Expect — Governing
All racial and ethnic minority groups in the United States are more likely to experience serious household physical health problems due to extreme weather events compared to non-Hispanic Whites.
Racial and ethnic health inequities caused by extreme U.S. weather events, 2017–2021: The EVITA Study — ScienceDirect
Hawaii has experienced an overall decline in annual rainfall over the last 30 years, but human-induced climate change has increased the intensity and frequency of heavy rainfall events, leading to greater flood risks.
📰 Source Timeline (4)
Follow how coverage of this story developed over time
- Gov. Josh Green calls this Hawaii’s most serious flooding since the 2004 Manoa floods and estimates total storm costs could top $1 billion, including damage to airports, schools, roads, homes and a Maui hospital in Kula.
- Authorities report roughly 5,500 people under evacuation orders north of Honolulu, with at least about 10 people taken to a hospital for hypothermia and no deaths or missing persons so far.
- Officials say Oahu’s Kaala peak received nearly 16 inches of rain in a day, other parts of Oahu saw 8–12 inches overnight, and additional 6–8 inches are forecast over the next two to three days.
- The Wahiawa Dam level rose from 79 to 84 feet overnight, about 6 feet below its maximum, before receding somewhat, and is being closely watched for possible failure as more rain is expected.
- The National Guard and Honolulu Fire Department airlifted 72 children and adults from the Our Lady of Kea’au spring break youth camp on Oahu’s west coast as a precaution, even though the camp sits on high ground.
- Honolulu officials report that search and rescue efforts were hampered by civilians flying personal drones over the flood zone, interfering with aerial operations.
- Honolulu officials say emergency sirens blared along Oahu’s North Shore as muddy floodwaters pushed homes off their foundations, swallowed vehicles and swept away some houses, though the exact number is not yet known.
- Honolulu’s 5:35 a.m. evacuation order covers more than 4,000 people downstream of the 120‑year‑old Wahiawa Dam, with officials warning it is "at risk of imminent failure" and water is actively running over the spillway.
- Roughly 185 people and 50 pets sheltering at Waialua High and Intermediate School had to be relocated by bus after that shelter flooded, amid 8–12 inches of overnight rain and what NWS calls "widespread life‑threatening flash flooding" in Haleiwa and Waialua.
- Gov. Josh Green says the Hawaii National Guard has been activated and describes chest‑high floodwaters on parts of northern Oahu, calling it a "very touch‑and‑go day," while a state senator says some residents are effectively isolated and unable to evacuate due to high water.
- Honolulu officials issued a specific 5:35 a.m. emergency alert Friday telling residents downstream of Wahiawa Dam to evacuate because it was 'at risk of imminent failure.'
- Honolulu Department of Emergency Management spokesperson Molly Pierce said the evacuation order covers more than 4,000 people and confirmed that 'water is actively running over the spillway right now.'
- City spokesperson Ian Scheuring said firefighters and lifeguards on jet skis are searching floodwaters for stranded people and that there are reports of homes being swept away, though the total is not yet known.
- Roughly 185 people and 50 pets sheltering at Waialua High and Intermediate School had to be evacuated and bussed to another center because that shelter itself flooded.
- Officials reported 8 to 12 inches of rain overnight in parts of north Oahu, on top of catastrophic flooding from last week’s storm, with the National Weather Service warning of 'widespread life-threatening flash flooding' particularly in Haleiwa and Waialua.