Context:

Hawaii faces its worst flooding in about two decades as two consecutive kona storms dump heavy rain and damaging winds across all islands, prompting urgent evacuations near a dam at imminent risk of failure and widespread road damage. Authorities report thousands evacuated and hundreds rescued, with no deaths so far but significant disruption to communities and infrastructure. Forecasts warn of continued heavy rain and flash flooding through the weekend, heightening alert status statewide. The event marks a pivotal moment for the state’s flood preparedness and may precipitate substantial rebuilding and resilience efforts in the near term.

Dive Deeper:

• On March 20, authorities evacuated Haleʻiwa and Waialua after warnings that all roads out faced imminent failure due to a 120-year-old dam near central Oahu, though officials later clarified the dam had not failed but was at risk. Governor Josh Green noted there were no fatalities or missing persons and that around 200 people were rescued while some others arrived at hospitals with hypothermia.

• The storms intensified rainfall to as much as 2 to 4 inches per hour, with the National Weather Service extending a flood watch statewide through March 22, as two systems continued to drive rain, thunderstorms, and rising flood risk. The Kaukonahua Stream near Wailua rose dramatically, and water and debris inundated roads and homes in Waialua and surrounding areas.

• Oahu’s dam landscape includes 13 dams, with seven classified as high or significant hazard; the Wahiawa dam is private, old, and considered in poor condition with high hazard potential, underscoring structural vulnerability during extreme weather events.

• The March 2026 event follows a pattern of kona storms that typically affect Hawaii’s leeward side; it is unusual to have two such storms within one month, amplifying rainfall totals and flood impacts compared with the 2004 Manoa Flood, which remains a benchmark for potential damage.

• Projected aggregate losses from the flooding could reach about $1 billion, covering damages to homes, roads, schools, airports, and Maui’s hospital, signaling a major economic and logistical strain alongside ongoing evacuation and rescue operations.