The already battered Hawaiian islands may face more flooding today, with a flood watch still in effect for the Big Island and a flood advisory in Maui issued through Monday afternoon.
The devastating “kona low,” the name for seasonal Hawaiian cyclones, continues to move across the state after causing widespread destruction in Oahu and Maui over the weekend. Possible heavy rain and isolated thunderstorms now threaten the Big Island with flooding, as an additional 1 to 2 inches of rain may come down over already saturated ground.
Several mountain locations have seen 20 to 40 inches of rain across the island chain during what has become Hawaii’s heaviest rainstorm in 20 years.
Evacuation warnings were lifted for most of the zones in Maui on Sunday, after cities such as Lahaina and Kahului received a year’s worth of rain in just a few days. Kahului has already experienced its wettest month on record with nearly 20 inches of rain.


Residents of Oahu’s North Shore were told to flee Saturday, with evacuation orders issued for 5,500 people living in the area known for its big-wave surfing community. Officials warned that the aging Wahiawa dam was “at risk of imminent failure,” a possibility that the state has said could result in “probable loss of human life.”
Floodwaters, which were so strong that locals described them as having currents, flowed through the streets of Oahu, lifting homes and totaling cars. Many North Shore residents left the area Saturday morning, returning in the afternoon to mud-caked houses with some finding their homes completely swept away by flooding.
Olivia Vergiels, a Haleiwa resident, returned to her home to find her floor and belongings covered in thick mud. “My house is totally unlivable right now,” Vergiels told NBC News.

Cleanup efforts were underway as locals came together to help displaced families returning to destroyed homes. Mac Burton, who lives in Wailua Beach, went out into the streets of the North Shore community Sunday to help his neighbors.
Cleanup, he said, is going to take months. “Anything that was, you know, 4 feet or below, it is just completely wiped out,” he said.

Burton said that many homes still have standing water in them and that even when the water level goes down, they’re left with “a ton of mud.” Wood homes that are still standing will face mold and water damage, he said.
“Everyone’s kind of in the street, just shoveling out mud and pulling out soaking debris and doing whatever they can to kind of start drying things out,” he said. “But we’re still without power here, so it’s making some of those efforts a little more difficult.”
Burton was awake when the flooding began early Saturday. As he watched the water level rise in the street, he began to wake up his neighbors. “I was knocking on doors and just kind of yelling, like, ‘Hey, I think everyone should wake up. This is kind of a big deal,’” he said.

Gov. Josh Green said the cost of the storm could top $1 billion, including damage to airports, schools, roads, homes and a Maui hospital in Kula.
The infrastructure of Oahu’s North Shore has been particularly hit hard. A boil-water notice remains in effect from the Honolulu Board of Water Supply for water users on the North Shore, urging them to boil tap water due to a risk of harmful bacteria.
Burton called this weekend’s flooding a “wake-up call” for the community and state government. “Mama nature is mad right now,” he said.
“This was the worst storm they’ve had in two decades. But, you know, it’s possible that these kind of storms are going to be more frequent in the future,” he continued.
