WAILUKU >> University of Hawaii researchers have developed an online tool that will inform the public when waves are expected to threaten west Maui shorelines, an area particularly prone to coastal erosion as sea levels rise.

The tool can forecast high sea levels and wave effects on 12 shoreline regions up to six days in advance, The Maui News reported.

“Maybe you would avoid traveling on Honoapiilani Highway during a high wave event, or maybe you would avoid going to certain beaches with your family,” Tara Owens of the University of Hawaii Sea Grant College Program said during an online presentation Tuesday.

A 2019 state Coastal Highway Program Report ranked two segments of Honoapiilani Highway in Lahaina among “critical” roads in the islands most susceptible to erosion and structural degradation.

The Pacific Islands Ocean Observing System’s Wave Run-Up Forecast was developed by researchers in the School of Ocean and Earth Science and Technology at the University of Hawaii.

Wave run-up is defined as the vertical reach of seawater on the land at any given time. When run-up levels are high, the risk for flooding and inundation increases.

The tool tries to predict seasonal waves and king tide events, like the ones that are known to flood Honoapiilani Highway in Olowalu, or that wash over the Kaanapali Beach public walkway or erode Napili Bay.

The forecast is not accurate when a tsunami, tropical storm or cyclone warnings are in effect, said Fiona Langenberger, communications and program coordinator for the Pacific Islands Ocean Observing System or PacIOOS.

Martin Guiles, a post doctoral researcher, said west Maui is more at risk than other parts of Maui because a fringing reef system allows for more short-period waves.

Combined with rising sea levels over the past couple of decades, he said this creates more opportunities for waves to “eat away at our shorelines.”