PDF Download: Kauaʻi Climate Change and Coastal Hazards Assessment

The island of Kauaʻi, the oldest of the main Hawaiian islands at approximately six million years of age, is one of the most remote islands in the world. This remoteness, coupled with an increasing vulnerability to coastal hazards due to climate change and sea-level rise, prompted the Kauaʻi County Planning Department to take a visionary step in its efforts to help the community prepare.

To effectively plan for short and long-term coastal hazard impacts from climate change, the Kauaʻi County Planning Department turned to the University of Hawaiʻi Sea Grant College Program (UH Sea Grant) for assistance. It commissioned Ruby Pap, a UH Sea Grant coastal land-use extension agent based on Kauaʻi, to coordinate a technical study, synthesizing all of the relevant coastal hazard science and providing a suite of policy and planning options to consider when incorporating sea-level rise into the Kauaʻi General Plan update. Although the current General Plan does address coastal hazards such as coastal erosion, it does not specifically recognize climate change and sea-level rise and its potential to exacerbate existing coastal hazards.

In response, Pap, along with a team of experts from Sea Grant in both coastal hazards science and planning, produced the Kauaʻi Climate Change and Coastal Hazards Assessment. The study found that addressing climate change related coastal hazards, such as sea-level rise, does not necessarily require the development of new programs. Kauaʻi already experiences and has the framework for addressing coastal flooding and wave inundation, erosion, inland flooding and wind. These hazards will be exacerbated by climate change and, while little can be done to prevent coastal hazard events, the study provides data, tools and recommendations for planners and the community to reduce adverse impacts through proper planning.

“We are grateful to the Sea Grant program for completing this technical study,” said Kauaʻi Mayor Bernard Carvalho, Jr. “This will be the first time we’ve significantly considered climate change in our General Plan process, and it will be invaluable to us as we move forward and make responsible decisions for our island’s future.”

Another important component of the study was the presentation of sea-level rise inundation maps for selected geographic areas on Kauaʻi, utilizing geographic information systems (GIS) data developed by the UH Coastal Geology Group for the National Oceanic and Atmospheric Administration’s Digital Coast Sea Level Rise and Coastal Flooding Impacts Viewer. The maps provide examples of what planners may create utilizing the GIS data and the tools suggested in the report. These maps may be used in the General Plan update process as a preliminary screening tool for sea-level rise inundation hazards, and to identify areas where future hazard, risk, and vulnerability assessments and other planning efforts should be focused.

Pap noted, “Kauaʻi County has taken a very important step in incorporating climate change into its planning process. Hopefully our report will go a long way to assist the entire community in understanding the coastal hazard implications of climate change, and how as a community we can adapt to these realities and become more resilient.”

The study was recently selected for presentation at the Biennial Meeting of the Coastal Society and National Summit on Coastal and Estuarine Restoration in Washington, D.C., in November.