History of Coastal Zone Management in Hawaiʻi and Review and Analysis of Options for Managed Retreat in Response to Sea-Level Rise

Abstract

A recent study at the University of Hawai‘i (Tavares et al. , 2020) modeled the impacts of future SLR on hardened shorelines and found that by mid-century a potential 40% of Oʻahu beaches could be lost. With the current state of coastal development, a 3.2 foot rise in sea level would leave 6,500 homes damaged or destroyed and displace 20,000 residents statewide (Hawaiʻi State OP, 2019) by 2100. Summers et al. (2018) suggest that current state and local coastal zone management policy has led to continued erosion and beach loss on the island of Oʻahu. While recent amendments to the state CZM statutes (HRS § 205a) ban private shore protection structures, there is still more work to be done in the area of legacy sea walls and existing structures. Managed retreat, the purposeful and coordinated movement of development and people away from the shoreline, offers a solution to both protect public trust lands (beaches) and minimize the habitation of these hazardous areas. This paper will review the history, significant legal decisions, and present-day dilemmas that characterize the federal, state, and county coastal management regime in Hawai‘i. After analyzing these factors, the paper will examine pathways for a managed retreat from the shoreline.