Kaua‘i County Council to vote on historic sea-level-rise-adaptation bill

LIHU‘E — A bill up for final vote at the Kaua‘i County Council Wednesday, Oct, 5, 2022, could put Kaua‘i at the vanguard of sea-level-rise adaptation by requiring all new construction in areas at risk of sea-level rise be elevated on stilts.

Draft Bill No. 2879, submitted by the county Planning Department, would require the lowest floor of new, habitable buildings in the sea-level-rise-constraint district be raised two feet above the highest projected sea-level-rise flood elevation.

New, non-habitable buildings would need to be raised one foot above that projection. The new restrictions would also apply to significant rebuilds of existing structures, where the cumulative cost equals or exceeds 50% of the market value of the building.

If passed and signed by Mayor Derek Kawakami, Kaua‘i will become one of the first municipalities to use long-term climate-change research to regulate building construction.

“This is an ordinance that is at the forefront of looking at sea-level-rise adaptation,” said Ka‘aina Hull, county Planning Department director, at the bill’s introduction. “It’s the first we’re aware of that approaches this from an individual property level.”

Unlike previous regulations which are based on historical data, this bill will use modeling data from the 2017 Hawai‘i Sea Level Rise Vulnerability and Adaptation Report as a guide.

Only Boston has implemented a similar ordinance based on long-term models, Hull said, and that ordinance only applies to large-scale construction.

Sea-level rise creates three hazards for those living in affected areas — coastal erosion, passive flooding and high wave run-up.

Local shoreline-setback ordinances already address the effects of coastal erosion, but the new ordinance would address the other two aspects.

Information on which areas are at risk of sea-level rise and to what extent can been seen on a map created by the Planning Commission viewable at https://tgilinks.com/3y88hc6

Over the course of the next century, sea-level rise could have a devastating effect on the island and the world at large.

Chip Fletcher, a leading sea-level-rise scientist from the University of Hawai‘i at Manoa who helped draft the bill, laid out the concerns related to sea-level rise at a September council Planning Committee meeting.

Fletcher presented a study from the National Oceanic and Atmospheric Administration and NASA projecting sea levels in Nawiliwili Harbor will rise between from 4 to 5.8 feet within the next century. He also reported there will be an exponential increase in king tide flooding by the 2030s.

“Sea level is committed to rise for centuries to millenia due to continuing deep-ocean warming and ice-sheet melt that will remain elevated for thousands of years,” said Fletcher. “These problems are real, they’re happening today, and we really need to react.”

Fletcher emphasized that, though Kaua‘i’s action against sea-level rise was among the most substantial in the country, it was just one step in a long-term effort to deal with the growing threat.

“We need to figure out how to move our families and our assets away from the shoreline,” said Fletcher. “And we need to figure out how to do that in an equitable way.”

The County Council will convene at 8:30 a.m. Wednesday, Oct. 5, 2022, at the Historic County Building second-floor council chambers, 4396 Rice St. in Lihu‘e.

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Guthrie Scrimgeour, reporter, can be reached at 808-647-0329 or gscrimgeour@thegardenisland.com.