The island of Kauai is expected to receive the heaviest rainfall on Thursday, according to KHON2, and a wet pattern is expected to last through the weekend.
Floodwaters destroyed homes and businesses on the island of Oahu, leaving returning evacuees in shock.
On Tuesday, Democratic Gov. David Ige issued an emergency declaration over the counties of Hawaii, Maui, Oahu, Kauai and Kalawao, noting that Maui County’s Peahi Bridge was washed out and Kaupakalua Bridge had been displaced.
The governor’s office said in a press release that “saturated ground conditions and increased water levels in reservoirs” increased the risk of erosion and fear of dam failure — though the 138-year-old Kaupakalua Dam ultimately did not fail and is now scheduled to be removed.
The National Weather Service reported that more than 13 inches fell over a period of eight hours in the vicinity of the reservoir.
“This has been unprecedented flooding,” Maui County Mayor Michael Victorino said in a statement on Facebook.
Hawaiian Electric said it had restored power to almost 20,000 customers on Wednesday night after a lightning storm caused a widespread outage in the Kahala, Kapahulu, Palolo, Waikiki, Manoa and Moiliili areas.
Ige’s disaster emergency relief period is set to last through May 8.
In recent decades, Hawaii has seen less rain and on Tuesday the U.S. Secretary of Agriculture Tom Vilsack approved a drought disaster declaration for parts of Maui County.
A 2010 report from the University of Hawaii’s Sea Grant College Program noted rainfall had declined by 15% over the past two decades. However, rain events with the heaviest downpours increased by 12% between 1958 and 2007.
In 2018, Kauai set a national record for the amount of rain recorded in a 24-hour period.
The Associated Press contributed to this report.