This article was originally published on The Inertia

Flash flooding has devastated parts of Hawaii, including the North Shore of Oahu and Haleiwa Town specifically. After nearly two days of torrential rain in Hawaii, Maui, Kalawao, and Kauai that saw up to three inches per hour, the city and county of Haleiwa issued an emergency evacuation notice on Tuesday. It has since been lifted. The damage, however, is extensive. Homes are flooded, cars are submerged, trees are down, and roads are closed. "I've lived on the North Shore my whole life," wrote Ryan De Seixas, the man who shot the aerial footage below, on YouTube. "I have never seen Haleiwa flood like this before."

Rick Blangiardi, mayor of the city and county of Honolulu, was watching the flooding carefully on Tuesday evening. "We're tracking the catastrophic flooding that happened this afternoon along the windward side and on North Shore coastlines," he said. "…we've had to evacuate the town of Haleiwa. My caution to anybody watching this is to please heed that warning and evacuate. We don't do that kind of warning capriciously. We do those with purpose."

The flooding in Haleiwa came from the Opae'ula Stream and the Anahulu River, which both run near Haleiwa. According the reports, the Opaeula Stream reached levels the National Weather Service called "particularly dangerous," rising from four to 16 feet over the course of the day. At around 4:30 p.m. on Tuesday afternoon, many businesses in Haleiwa Town began evacuating, shortly after the order was given. The flooding occurred extraordinarily quickly. "(I said) the water level is going up but it's not at the dangerous line yet," Quinn Cao, who works at Jenny's Shrimp Truck, told KHON2 about a call she received inquiring whether they were seeing rising waters in the area. "After I hung up, I took a look again. I found that half of the parking lot was already (flooding) - it (was) all filled up with the river."

When dawn broke on Wednesday morning, the extent of the damage was clear. Hawaii's Gov. David Ige has since signed an emergency proclamation. The heavy rains are expected to continue through Friday, causing concern that more flooding may occur. "The emergency proclamation makes state general funds available that can be used quickly and efficiently to help those impacted by the severe weather, which is expected to continue until Friday," Gov. Ige wrote.

The Washington Post reported that the Waiahole Stream, located above the Kamehameha Highway, saw flow rates of almost 9,000 cubic-feet-per-second. The previous record for the stream over the last two decades (set in 2012) was 432 cubic feet per second. The typical rate is about 90 cubic-feet-per-second. The heavy rain was caused by a phenomenon called "upsloping," where moist air is forced up a mountain and transformed into heavy rain.

This article was originally published on The Inertia

World Surf League
Download it for free on the App store. Download it for free on Google Play.
Download
Download