UPDATE: 8:45 a.m.

The city’s Department of Environmental Services has reported wastewater spills at facilities in Ahuimanu, Kailua and Waimanalo during Friday’s heavy rain.

According to city officials, the three spills were at:

>> Ahuimanu Preliminary Treatment Facility at 9:20 a.m. Friday when elevated flows exceeded storage capacity, causing a manhole at the facility to overflow into an on-site storm runoff retention basin. The basin subsequently reached capacity and discharged into Ahuimanu Stream. The spill is ongoing.

>> Kailua Regional Wastewater Treatment Plant at 10:10 p.m. when the Tunnel Influent Pump Station reached maximum capacity. Personnel installed portable pumps to manage the inflow. During testing and startup, about 30,000 gallons of wastewater were discharged onto an adjacent grassy area, flowing into Nuupia Pond. The spill was stopped in 10 minutes.

>> Waimanalo Wastewater Treatment Plant at 10 p.m. when high flows overwhelmed the facility, causing an ongoing spill at the Headworks and an initial spill at the Final Clarifier scum pit that reached Puha Stream. While the scum pit spill was stopped at 1 a.m. on March 21, the Headworks spill remains active.

ENV crews are monitoring conditions and calculating total discharge volumes for all locations, officials said.

8:25 a.m.

The National Weather Service has extended the flash flood warning for Oahu until 11 a.m.

“At 7:47 a.m., emergency management continued to report road closures across Oahu due to recent flooding,” the updated warning says. “Additional bands of heavy showers and thunderstorms continue to pass over the southeast half of Oahu, with rain rates as high as 1 to 2 inches per hour.”

The islands of Molokai and Lanai remain under flood advisories this morning, and the entire state is under a flood watch through Sunday afternoon.

5:10 a.m.

Oahu remains under a flash flood warning until at least 8 a.m. today as heavy rain continues to fall on parts of the island.

“At 4:55 a.m., emergency management reported closed roads islandwide as a result of Friday`s flooding,” said the updated warning from the National Weather Service. “While the latest radar depicts light to moderate showers, additional bands of moderate to potentially locally heavy showers may likely in from the south during the early-morning hours.”

The warning may need to be extended beyond 8 a.m. if flooding persists.

Forecasters advise the public to stay away from streams, rivers, drainage ditches, and culverts, even if they are dry, and to not cross fast-flowing or rising water in a vehicle, or on foot.

The islands of Molokai and Lanai are under flood advisories this morning, and the entire state is under a flood watch through Sunday afternoon as the second major Kona-low system in two weeks continues to pound the islands.

The forecast for Oahu calls for rain showers, with possibly thunderstorms, throughout the weekend.

Residents of Waialua and Haleiwa remain under an evacuation order. Honolulu city officials continue to urge residents in Waialua to leave now because the remaining access road out of the area is at high risk of failure if rainfall continues.

“Residents are urged to vacate the area now while conditions are stable. Delaying may result in becoming stranded if conditions worsen. Please prioritize personal safety and exit the area via the remaining open route immediately. Leave now while conditions are safe to prevent becoming stuck,” an updated city alert says.

For the evacuation and shelter map, go to https://p.veoci.com/hnlevac Opens in a new tab.

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>> A list of evacuation shelters, assembly areas and closures Opens in a new tab

>> North Shore evacuees feared for their lives as water swelled Opens in a new tab

>> Flooding forces 233 rescues as storm grows Opens in a new tab

>> City monitors Wahiawa Dam for failure Opens in a new tab

>> Oahu residents asked to conserve water during storm Opens in a new tab

>> Hawaii Community Foundation activates disaster fund Opens in a new tab

>> PHOTOS: Kona low storm system pummels Oahu with rain and floods Opens in a new tab

PREVIOUS COVERAGE

A powerful Kona low brought intense rainfall to the islands on Friday, triggering evacuations and leaving widespread damage that continued into early Saturday morning.

The most critical situation unfolded on Oahu’s North Shore where torrential rain—up to 8 to 12 inches in some areas—caused life-threatening flooding in communities like Haleiwa and Waialua.

Officials issued a mandatory evacuation order for areas downstream of the Wahiawa Dam after warnings that the structure was at risk of failure. Rising water levels and continued rainfall are keeping authorities on high alert.

Floodwaters have inundated roads, homes and neighborhoods across northern and central Oahu, cutting off access to entire communities. Officials warned that all roads out of Waialua were at risk of failure Friday night, urging anyone remaining to leave before conditions worsened. Across the island, there were landslides and downed trees that made roads impassable.

Hawaiian Electric also reported power outages affecting thousands of customers, particularly on the North Shore. Electricity was shut off as a safety measure during flooding and evacuation efforts. Call HECO’s Trouble Line at 1-855-304-1212 to report any damage to power lines or poles.

Forecasters caution that more heavy showers could redevelop. The entire state remains under a flood watch through Sunday. Conditions may gradually improve starting Monday as the storm system moves away.