Hawaii's Worst Flooding in 20 Years Threatens Dam

Catastrophic flooding has slammed Hawaii with the worst conditions the state has seen in more than two decades, forcing thousands of residents to flee their homes, threatening an aging dam and stretching emergency crews across Oahu as more rain bears down on already saturated ground.

Emergency alerts sent early Saturday carried an urgent command: “LEAVE NOW.” Officials warned that the remaining access road out of Waialua, a community on Oahu’s North Shore, faced a high risk of failure if rainfall continued. Some 5,500 residents north of Honolulu fell under evacuation orders as muddy floodwaters swept through neighborhoods, lifted homes off their foundations and carried cars through streets.

The flooding is the most serious Hawaii has experienced since 2004, when floods in Manoa inundated homes and a University of Hawaii library. This time, the damage footprint is far larger and the financial toll potentially staggering. Gov. Josh Green said the cost could surpass $1 billion, counting damage to airports, schools, roads, private homes and a hospital in Kula on Maui.

“This is going to have a very serious consequence for us as a state,” Green said at a news conference.

The destruction hit Oahu’s North Shore particularly hard. The area, famous worldwide for its massive surf breaks, watched floodwaters tear through communities as officials issued warnings about a 120-year-old dam that could fail under the pressure of the swollen waterways. Most of the state fell under a flood watch, with Haleiwa and Waialua under active flash flood warnings from the National Weather Service.

The numbers tell the scale of the emergency. More than 200 people have been rescued. About 10 were hospitalized with hypothermia. No deaths were reported and no one remained unaccounted for as of the latest updates, though crews continued searching by air and water for anyone stranded.

Rescue operations ran into an unexpected complication. Ian Scheuring, a spokesperson for Honolulu, said personal drones flown by people trying to capture footage of the flooding were hampering search-and-rescue aircraft. Emergency managers urged the public to keep drones grounded.

Among the more dramatic rescues, the National Guard and Honolulu Fire Department airlifted 72 children and adults from a spring break youth camp at a retreat on Oahu’s west coast called Our Lady of Kea’au. The camp sits on high ground, but the mayor said authorities did not want to leave the group there given the uncertainty ahead.

The rainfall amounts explain why officials were caught in an escalating crisis so quickly. Parts of Oahu recorded 8 to 12 inches of rain overnight. Kaala, the island’s highest peak, received nearly 16 inches in a single day, according to the National Weather Service. The problem was compounded by timing. Heavy rains from a winter storm the previous week had already saturated the soil, leaving it unable to absorb additional water. When the new system arrived, runoff was nearly immediate and extreme.

Honolulu Mayor Rick Blangiardi said the full scope of the damage had not yet been assessed. Dozens of homes were confirmed damaged, with officials acknowledging the number could reach into the hundreds once crews gained full access. “There’s no question that the damage done thus far has been catastrophic,” he said.

A forecast for an additional 6 to 8 inches of rain over Oahu during the weekend gave officials little room for optimism. Green said his chief of staff had spoken with the White House and received assurances of federal support, a critical step given the scale of what state and county agencies are managing.

South Florida residents watching this disaster unfold may recognize the cycle: saturated land, an aging infrastructure network, repeated storms in close succession. The difference here is that Hawaii has almost no buffer left. The ground cannot absorb more water, the roads are failing and emergency crews are already stretched. What happens when the next band of rain arrives will determine whether this becomes a crisis the state manages or one that defines it.