‘Little by little cities will have to recede’: Coastal flooding is the sleeper climate issue

Virginia Jones and her family faced a harrowing experience when their home in Bogangar, near Cabarita Beach, was flooded in late February 2022. The family, which included two adults, two children aged nine and twelve, and two dogs, had lived in the area for nearly a decade. They had chosen the location for its proximity to nature and its relatively stable conditions, until the night of the flood. Heavy rain led to rising waters that eventually reached the doorstep of their home, submerging vehicles and forcing them to evacuate using a neighbor's kayak. Upon returning days later, they discovered that the water had risen approximately 30 centimeters up the walls, necessitating extensive repairs beyond simple cleanup. The damage was severe enough that the family could not return until over a year later, after implementing drastic flood-proofing measures. The Jones-Lawson family raised their home entirely, ensuring the front door now sits well above the flood line, more than double its previous height, and incorporated additional structural changes such as adding a second floor. These modifications reflect a growing trend among residents in coastal regions who are increasingly confronting the reality of rising sea levels and intensified storm surges. Their situation is emblematic of a broader challenge facing New South Wales, where coastal flooding is emerging as a critical, often overlooked, threat to urban infrastructure and residential areas. Across the state, many neighborhoods are situated on low-lying land adjacent to coastal lagoons, lakes, and estuaries. For instance, Lake Illawarra, Lake Tuggerah, and Lake Macquarie each support large populations, with tens of thousands of residents living along their shores. Similarly, the northern beaches of Sydney, home to approximately 273,000 people, are encircled by water on three sides, placing them at heightened risk. Residents in these areas are already experiencing increased insurance costs and the physical consequences of frequent flooding. The problem extends further inland, affecting communities in low-lying zones such as those surrounding Gamay-Botany Bay and the tidal reaches of the Cooks River. According to the NSW State Disaster Mitigation Plan released in February 2024, coastal hazards represent the most pressing long-term risk to the built environment due to rising sea levels. The plan outlines potential outcomes ranging from the gradual erosion of sandy shorelines to the permanent or recurring inundation of land above the current high-tide line. With about 85 percent of the state’s population residing within 50 kilometers of the coast, New South Wales is uniquely vulnerable to these threats. The plan identifies specific local government areas (LGAs) as being at particular risk, noting that Shellharbour, Newcastle, and Port Stephens held the top positions in 2023. However, projections indicate that by 2060, the most at-risk areas will shift to Port Macquarie-Hastings, followed by the Clarence Valley and the Tweed region. The LGAs with the highest overall risk, factoring in the number of exposed properties and assets, are currently Central Coast, Northern Beaches, and Tweed. Yet, these rankings are expected to evolve, with Northern Beaches, Byron, and Central Coast anticipated to take precedence in the coming decades. Climate scientist Russell Wise from CSIRO emphasizes the urgency of addressing this crisis through strategic planning, including discussions about managed retreat from high-risk zones. He warns that relocation of entire communities may become necessary as efforts to protect the entire coastline prove unsustainable. Such measures, he suggests, would involve difficult trade-offs, such as the loss of valuable beachfront areas that contribute to tourism and recreation. The increasing frequency and severity of coastal flooding underscore the need for proactive adaptation strategies. As the climate continues to change, the pressure on coastal communities to adjust their living arrangements will intensify, requiring coordinated action from governments, planners, and residents alike. The experiences of families like the Jones-Lawsons serve as a sobering reminder of the challenges ahead, highlighting the importance of preparedness and resilience in the face of an evolving environmental landscape.