It has been almost a year since Kaua’i County, Hawai’i, made a paradigm shift in how it protects private property from rising seas driven by climate change.
Rather than relying on historic flood hazard data to inform construction standards, Kaua’i County looks to the latest science on predicted flood hazards in the year 2100, with the compounding effects of sea-level rise. Thanks to an ordinance passed in October 2022, new and substantially renovated buildings in certain areas are required to be elevated to withstand such projected flood hazards, based on models from University of Hawai’i scientists. The rules made the county one of the first in the nation to “commit to using scientific model projections as the basis for construction and planning regulations,” according to the university.
“It's our first attempt to use … predictions about the future and bake them into a regulatory framework for development,” said Alan Clinton, administrative planning officer at Kaua’i County. Residential buildings are required to be elevated 2 feet above the highest sea-level rise flood elevation, while nonresidential structures are required to be elevated 1 foot above that level.
The ordinance seeks to protect residents and buildings from worsening flood impacts. But in an area where Clinton said the shorelines have “almost been monopolized in many places by some of the wealthiest people in the world,” the rules also aim to save taxpayer dollars on costly flood-control projects and ensure that those who live in risky areas take responsibility for their actions.
The county knew that such a policy needed to be paired with high-quality visualization and communications tools, Clinton said. “With this much data, this much information to share, it really would not make sense to try to make a whole bunch of PDF printouts to implement and utilize this policy,” Clinton said. That is why the county used technology from software company Esri to create what it calls the “Sea Level Rise Constraint District Viewer”: a publicly available online map that shows the projected sea-level rise flood elevation that builders must comply with.
“In the world of land-use planning, we try to steer away from being labeled arbitrary and capricious for our decision making,” Clinton said. “We want to get to a point where we can say these are the data. This is specific to your structure and specific to your lot, and it's based [on] the science and the models produced by our academic partners.”
He added that the county hopes the University of Hawai’i will, in the coming years, publish even higher-quality models that his team can slide into the policy and project process. “It's a lot easier to adopt new data than pass a brand-new policy,” Clinton said. He called the solution highly transferable, noting that as long as an area has the necessary models, they could take a similar approach as Kaua’i County did.
The county also developed an app that allows people to generate a PDF report showing whether a proposed structure is subject to the rules and the maximum flood depth it is exposed to. The report can be printed out and attached to applications to the county planning department, Clinton said. “This isn't an instance of us exporting a potentially challenging management thing to do in-house and putting it on the burden of the architect or the engineer who will be submitting the plans,” he said.
These digital tools eased the passage of the ordinance, which was unanimously approved by the county council and signed by the mayor after two hours of presentations and discussion, Clinton said. “We're kind of crediting that to the process that we went through to vet this program legally, with scientific experts, as well as the tools we use to prepare and communicate the information and the data.”
Clinton acknowledged that while the county is proud of the ordinance, it is “considered an abject failure in the eyes of our community.” Kaua’i County is populated with people who hold two diverging opinions on how the government should manage coastlines, he said. There are those who don’t want any new construction near the coastline and those who think no additional regulation is needed.
“This is a middle-ground solution that is workable,” Clinton said. “But it certainly doesn't address all the concerns of many of our community members.”