Rising sea levels along Hawai‘i’s shorelines call for state and local governments to take action by means of a wide range of coastal land use policy tools designed to help Hawai‘i successfully adapt to climate change. Hawai‘i is expected to experience sea-level rise of one foot by 2050 and three feet by the end of the century. Sea-level rise of this magnitude poses significant economic, social, and environmental challenges requiring leadership and bold action by state and local governments, which are uniquely positioned to implement land use policy tools to shape Hawai‘i’s efforts to successfully adapt to rising sea levels in the coming decades.

The purpose of this Tool Kit is to identify and explain key land use policy tools for state and local government agencies and officials to facilitate leadership and action in support of sea-level rise adaptation in Hawai‘i. Across the United States and around the world, governments are developing policy tools to proactively adapt to threats from rising sea levels. For example, the U.S. Army Corps of Engineers now requires consideration of sea-level rise impacts to coastal and estuarine zones in all phases of its civil works programs. In addition to incorporating projected sea-level rise in land use decisionmaking, experts also recommend that governments locate coastal development where it is protected from hazards, and ensure structures are resilient to flooding and other coastal hazards exacerbated by sea-level rise.

Accordingly, this Tool Kit surveys state adaptation plans, federal efforts, and other key sources to identify and discuss important land use policy tools for Hawai‘i and suggests how these policies can be used by state and local governments to avoid or lessen the impacts of sea-level rise and related coastal hazards. Adaptation planning for sea-level rise and climate change is necessary to protect public health and safety, both now and in the future, and it is widely acknowledged that proactive planning can be more effective and less costly than responding reactively to climate change impacts as they occur. Because sea-level rise and climate change exacerbate existing coastal hazards, adapting now ultimately will lessen future economic, social, and environmental impacts of rising sea levels. This Tool Kit first reviews scientific research showing that climate change is causing sea-level rise in the Hawaiian Islands and around the world. The physical and environmental impacts of rising sea levels – including coastal erosion, flooding, wave inundation, and rising water tables – are chronicled, as well as the economic and social impacts. The necessity for “adaptive management” in the face of uncertainty is noted, as is the important role to be played by state and local governments in implementing adaptation measures.