With nearly a third of the beachfront homes on O‘ahu’s North Shore sitting within 20 feet of the shoreline and ongoing erosion along the coastline, the North Shore Coastal Resilience Working Group (NSCRWG) is urging government leaders and policymakers to help address the problem that is literally in their backyard.
The Surfrider Foundation, Surfrider Foundation Oʻahu Chapter, University of Hawaiʻi Sea Grant, and SSFM International, a Honolulu planning and engineering firm, convened the working group that is composed of North Shore residents and landowners, state and county government officials, coastal scientists, engineers, planners and nonprofit leaders. Over the past two years, the group has met regularly and has identified concrete solutions to combat the chronic coastal erosion and beach loss plaguing the North Shore, extending from Kaʻena Point to Velzyland.
The solutions are included in a recently published report by the group titled, “Adaptive Coastal Management Recommendations, Actions and Strategies.” The report documents that long-term erosion is driven by a combination of natural sand movement from large waves, sea level rise over the past century, degradation of natural dune systems from development, and the removal of sand from some beaches by sand mining operations and shoreline armoring. As part of the report, three coastal erosion “hot spots” on the North Shore were identified: Sunset/Kammies, Chun’s/Laniākea and Mokulēʻia. The report also discusses coastal adaptation challenges and explores the relative merits, costs, benefits and feasibility of various solutions.
While beach loss is an urgent issue, the working group recognized that a phased approach is necessary. Phased adaptation options include short-term solutions like sand pushing and dune restoration. Adaptation pathways are conceptual planning approaches addressing the uncertainty and challenges of climate change decision‐making. Adaptation triggers such as sea level rise thresholds, erosion impacts, beach width, frequency of flooding, and infrastructure damage, provide guide posts along the way to help identify what actions should be implemented.
According to federal interagency reports, one foot of sea level rise is expected for Hawaiʻi by 2050, with three to four feet of sea level rise anticipated by the end of this century (in an “Intermediate” or mid-range scenario relative to a baseline year of 2000)(Sweet et al., 2022). However, more than 90% of North Shore beaches are projected to be in a state of chronic erosion with just 10 inches (0.25 meters) of mean sea level rise, a scenario that is likely to occur within the next 30 years (Tavares, et al., 2020).
As part of its discussions, the group identified seven critical concerns that must be remedied in order to proactively and holistically support the North Shore community in adapting to severe coastal erosion.
7 Critical Concerns of the NSCRWG Related to Community Vulnerability and Coastal Resource Management:
- Immediate erosion threats and impacts to homes, highways and public infrastructure
- Lack of options and transparent, publicly-shared guidelines for homeowners impacted by shoreline erosion
- Increasing erosion and flood risks with climate change and sea level rise
- Damaged and limited public beach access due to erosion, beach loss and inappropriate response measures
- Environmental impacts of unauthorized and expired materials on the shoreline
- Lack of cohesive policy framework and financing mechanisms for managed retreat
- Absence of a comprehensive coastal erosion strategy and long-term vision for the North Shore.
The NSCRWG further identified the following six recommendations for immediate action by relevant organizations, agencies and policy-makers:
6 Recommendations for Immediate Action:
- Improve guidelines and limitations for emergency shoreline erosion management and strengthen enforcement against unauthorized work and materials
- Establish a statewide managed retreat program, with the North Shore as a pilot area, to provide a pathway for affected landowners to voluntarily vacate affected properties and utilize shoreline areas for public benefit
- Improve interagency coordination for shoreline erosion and flood management, which overlaps jurisdictional and ownership boundaries
- Develop a beach and dune management plan for North Shore beach parks and accessways; include guidelines that may be transferable to efforts fronting privately-owned lands
- Develop a comprehensive climate change and sea level rise vulnerability assessment and adaptation strategy for the North Shore
- Continue the NSCRWG and expand community discussions, engagement and outreach.
The Working Group is urging state and local leaders to review these considerations and take immediate action. This may be in the form of legislation for the upcoming 2023 session, as well as improving internal processes and communications between state and local agencies. The Working Group plans to continue its efforts and public outreach about solutions to the chronic erosion on the North Shore. The Group also hopes that it can serve as a model to be replicated across other communities in Hawaiʻi that are facing similar challenges.