Imminent failure risk at Wahiawa Dam triggers emergency evacuations in Haleiwa and Waialua, Hawaii
Wahiawa Dam on Oʻahu, Hawaii, was placed under an imminent failure risk alert on March 20, 2026, prompting emergency evacuations in downstream communities, including Haleiwa and Waialua.
Image credit: Honolulu, Hi DEM
Wahiawa Dam on the island of Oʻahu, Hawaii, was placed under an imminent failure risk alert on March 20, prompting emergency management authorities to issue evacuation orders for downstream communities exposed to potential life-threatening flooding.
The evacuation zone includes parts of Haleiwa and Waialua along the Kaukonahua Stream system, where officials warned that a failure of the dam could generate rapid-onset flooding affecting populated low-lying areas. Authorities instructed residents to leave immediately and avoid delaying evacuation to gather belongings.
The warning was supported by the National Weather Service in Honolulu, which issued a Flash Flood Warning for a dam-failure scenario along the Kaukonahua Stream, stating that flooding was already occurring in the area and that law enforcement reported the dam at imminent risk of failure.
Emergency management guidance emphasized the urgency of evacuation, advising residents to move away from downstream zones using designated routes and to avoid flooded roads and moving water. Traffic congestion was reported, and residents were encouraged to carpool where possible to reduce delays.
Infrastructure impacts were reported in the affected area, including the closure of the Karsten Thot Bridge on Kamehameha Highway, with traffic redirected through alternative routes toward Wahiawa via Kamananui Road and Wilikina Drive.
Assembly areas were opened to support evacuees, including Wahiawa District Park, Leilehua High School, and Kahuku Elementary School, while at least one facility in Waialua was reported closed due to flooding conditions.
The dam emergency developed under conditions of intense rainfall associated with a second Kona low system affecting Hawaiʻi on March 20. The event follows an earlier incident on March 14, 2026, when an evacuation warning was issued after a possible failure alert at the same dam.
Officials have not confirmed a failure of the dam as of the latest update, maintaining that the situation represents an imminent risk.
Authorities advised residents to remain outside evacuation zones until further notice and to use emergency services strictly for life-threatening situations, warning against attempting to travel through flooded areas.
References:
1 Update: WAHIAWA DAM HAS NOT FAILED BUT IS AT IMMINENT RISK OF FAILURE – HNL Alert – Issued at 09:00 LT on March 20, 2026
I'm a dedicated researcher, journalist, and editor at The Watchers. With over 20 years of experience in the media industry, I specialize in hard science news, focusing on extreme weather, seismic and volcanic activity, space weather, and astronomy, including near-Earth objects and planetary defense strategies. You can reach me at teo /at/ watchers.news.
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