Managed Retreat as a Strategy to Mitigate Sea Level Rise Impacts in Hawaiʻi

Abstract

Abstract

Sea levels are projected to rise and remain elevated for centuries to millennia, even with efforts to mitigate carbon emissions. The foremost impacts of rising sea levels are felt by low-lying coastal communities. Coastal erosion, among these impacts, is already significant, particularly affecting Hawaiian beaches. Strategies like protective and accommodative measures are employed to counteract the effects of sea level rise, yet they may prove inadequate and could exacerbate beach loss. Research by Summers et al. (2018) indicated that erosion had claimed 19% of Hawaiʻi’s beaches by 2015. In order for a beach to survive, it must be able to migrate landward unimpeded. The State of Hawaiʻi bears a constitutional responsibility to preserve its natural resources, including beaches, for current and future generations. However, state and local government policies have placed more effort on asset management rather than beach protection and preservation in response to sea level rise; consequently, failing in their constitutional duty to preserve Hawaiʻi’s beaches. Managed retreat is the strategic and purposeful relocation or abandonment of structures to manage the risk of natural hazards and utilize an avoidance strategy to eliminate risk. Successful implementation of managed retreat policies in Hawaiʻi could safeguard the public from hazards and facilitate natural beach replenishment through shoreline recession; and allow the State to fulfill their constitutional obligations.