Hawaii Flooding Forces Thousands to Evacuate Across Maui and Oahu

Muddy floodwaters pushed homes off their foundations, swallowed vehicles and triggered the largest mass evacuation Hawaii had seen in two decades, as a Kona Low weather system delivered back-to-back storms to an already saturated archipelago. Raging waters lifted homes and cars and prompted evacuation orders for 5,500 people north of Honolulu. At the center of it all stood a dam nearly as old as the 20th century itself.

The Wahiawa Dam, in Oahu's North Shore area, was at risk of "collapse or breach." The dam had risen within less than three inches of the 84-foot evacuation level by 4:30 a.m. and continued rising, with water pouring over its spillway at a pace of 1,500 gallons per second; just before 8:30 a.m., the county posted an "imminent dam failure" notification. Residents in the towns of Waialua and Haleiwa were told to leave immediately due to "potential life-threatening flooding."

The shelter at Waialua High and Intermediate School, one of several assembly areas opened across the North Shore, was itself overwhelmed. About 185 people and 50 pets who had sought refuge there were bussed to another evacuation center as flooding encroached on the building. Governor Josh Green announced on social media that the Hawaii National Guard had been activated. The National Guard deployed 200 troops in response to the storm.

"The storm of course is very severe right now, particularly on the northern part of Oahu," Green said, describing chest-high floodwaters. "It's going to be a very touch-and-go day." At a Friday news conference, he was more blunt: "This is the largest flood that we've had in Hawaii in 20 years." Green said the flooding was the state's most serious since the 2004 floods in Manoa, which inundated homes and a University of Hawaii library.

Crews rescued 236 people from treacherous conditions. About 10 of those people were taken to the hospital with hypothermia. The National Guard and Honolulu Fire Department airlifted 72 children and adults who had been attending a spring break youth camp at a retreat on Oahu's west coast called Our Lady of Kea'au. Honolulu Fire Department images captured a building collapsed in high muddy floodwaters and two men and two dogs standing on a tractor surrounded by rising water.

The meteorological culprit was a Kona Low, a low-pressure weather system that usually forms in the winter months and brings heavy rain and strong winds. It was the second such system in a week to batter the islands, with the prior storm having already washed away roads and homes across the state and left the ground fully saturated. The first storm dumped more than 15 inches of rain across all of Hawaii's islands, with Maui's higher elevations recording more than two feet. Some areas then received more than 10 additional inches of rainfall during this second event, with winds up to 100 mph. Green told residents that some parts of the state had received 40 to 50 inches of rain across the 10-day stretch.

Green said the cost of the storm could top $1 billion, including damage to airports, schools, roads, homes and a Maui hospital in Kula. "This is going to have a very serious consequence for us as a state," he said. On Maui, officials issued an evacuation warning for several parts of Lahaina as nearby retention basins neared capacity. Some of the affected neighborhoods were among those burned in the 2023 wildfire that destroyed much of the town.

The earthen Wahiawa Dam was built in 1906 to increase sugar production for the Waialua Agricultural Company, which eventually became a subsidiary of Dole Food Company. It was reconstructed following a collapse in 1921. The state has sent Dole four notices of deficiency about the dam since 2009 and, five years ago, fined the company $20,000 for failing to address safety deficiencies on time.

Water levels at the dam began to fall later Friday night, though the dam continued to be monitored as levels remained elevated. The dam appeared to be less of an immediate concern by Saturday morning, said Molly Pierce, spokesperson for Oahu's Department of Emergency Management, though she noted substantial flooding including in residential parts of Honolulu. No deaths were reported as of Sunday afternoon, Pierce confirmed.

Green said his chief of staff spoke to the White House and received assurances of federal support. Green issued several emergency proclamations due to the storm, and a disaster relief period was placed in effect through April 13.