Resilient Economies Strategies for Sinking Cities and Flood Risks 2025

Executive summary Urban land subsidence, commonly referred to as “sinking cities”, is an underrecognized global challenge. This report demonstrates that subsidence can threaten the prosperity and liveability of cities worldwide. Subsidence is driven primarily by unsustainable human behaviours from groundwater extraction to rapid urbanization. These pressures can heighten flood risks, infrastructure damage and displacement. When combined with sea-level rise and extreme weather, subsidence can transform manageable risks into existential threats for businesses, governments and communities. Subsidence often progresses gradually and invisibly, masking its true scale until critical thresholds are crossed. The private sector faces direct risks to assets, supply chains and profitability, while governments must contend with additional costs for infrastructure management. Subsidence undermines buildings, utilities and transport systems, leading to property devaluation, increased maintenance costs and service disruptions. Beyond economic costs, subsidence threatens societal well-being and environmental systems. Communities face displacement, property loss and public health challenges. Environmental consequences include loss of vital ecosystems that buffer places against storms and erosion. Despite its magnitude, land subsidence remains underrepresented in global urban and climate agendas, hindered by fragmented knowledge and data, a lack of international standards and insufficient investment. Early, cohesive interventions are essential. Case studies from Tokyo, Shanghai and Rotterdam demonstrate that cities can mitigate and adapt to land subsidence through integrated solutions, while Jakarta is on a trajectory to address its sinking challenges. Key measures include regulatory reforms, sustainable groundwater management, infrastructure investment and nature-based solutions. The experiences of these cities highlight the need to shift from reactive crisis management to proactive, long-term resilience building. The report identifies several foundational drivers of change for public and private stakeholders: –Value land and water as strategic assets: Manage resources as finite assets essential for economic, social and environmental benefits. –Strengthen governance and leadership: Encourage proactive leadership, regulatory guidance and collaboration to enable systems-based solutions, while empowering communities and businesses as agents of change. –Operationalize systems thinking: Implement holistic strategies to prevent, mitigate, adapt and enable resilience to subsidence and its interplay with climate risks. –Commit to evidence-based approaches: Use reliable data, expert insights and global case studies to inform risk assessments, interventions and investments, and overcome fragmented information. –Invest in infrastructure resilience: Upfront investments in subsidence monitoring, building resilient infrastructure, technology and innovation are essential to reduce the long-term costs of inaction. Land subsidence can accelerate social, economic and environmental risks. Only by treating subsidence as a core component of urban resilience agendas can economies and societies enable future prosperity and liveability.Ignoring sinking cities today means accepting escalating costs, stranded assets and social disruption tomorrow. Resilient Economies: Strategies for Sinking Cities and Flood Risks 4