A landslide caused by heavy rain led to the closure of Pali Highway’s town-bound lanes Wednesday afternoon and could remain closed through the weekend, according to state officials.
The landslide occurred just past the second tunnel, with thick mud and fallen trees blocking town-bound lanes.
The Hawaii Department of Transportation alerted the public of the closure on social media channels at about 1:15 p.m. Wednesday and asked motorists to reroute to Kamehameha Highway. The City and County of Honolulu also sent out an alert on HNL.Info.
In a 3 p.m. update, DOT said the town-bound lanes of Pali Highway will remain closed as crews remove debris and assess the hillside and trees.
“The closure of the town-bound lanes and diversion of traffic to Kamehameha Highway at Castle Junction could potentially continue through the weekend,” said the department in a news release. “HDOT will update on the status of the closure after assessment of the hillside is completed and staff is confident the water infiltration behind the hillside is addressed.”
Motorists are encouraged to use Likelike Highway or the H-3 freeway to travel between the windward side and Honolulu until further notice.
The National Weather Service issued a flash flood warning for Oahu until 7:30 p.m. Wednesday. At 4:58 p.m. Wednesday, NWS said that radar and automated rain gauges showed heavy rain falling over the Koolau mountains.
“Rapid rises in water levels are expected to lead to flooding on Kamehameha Highway near Waiahole. Rain was falling at a rate of one to two inches per hour. Flash flooding is ongoing or expected to begin shortly,” the warning said.
As of 4 p.m. Wednesday, Maunawili saw 6.85 inches in total rainfall over the previous 24 hours, according to NWS. NWS forecast occasional showers this morning and likely showers in the afternoon in the windward and mountain areas.
This isn’t the first time a portion of Pali Highway has been closed following a landslide. A landslide in late February left a large tree on the highway, resulting in the closure of both Kailua-bound lanes of the highway overnight. In February 2019, the state declared Pali Highway a “disaster area” after multiple landslides near and onto the highway after days of heavy rainfall.
Portions of Pali Highway also have been closed periodically throughout the Pali Highway Resurfacing project, which began in late 2017 and was “substantially completed” on Friday. The two-phase project involved tasks like the installation of LED streetlights, highway resurfacing, guardrail replacements and paving work. A final inspection of the project is set for early January.