Resilient Economies Strategies for Sinking Cities and Flood Risks 2025

What are the economic, social and environmental implications? The impacts of land subsidence extend far beyond the physical landscape, carrying critical economic, social, health and environmental challenges for governments, businesses and communities. Economic implications The absence of standardized international frameworks for assessing and comparing the economic costs of subsidence, particularly when compounded by sea-level rise and extreme weather, complicates effective global risk management. Nevertheless, emerging research and data point to the financial burden. Investing in mitigation is 5–7 times more economically efficient than repairing/rebuilding post-disaster. Jonathan Reckford, CEO, Habitat for Humanity Economic consequences of sinking cities (land subsidence) FIGURE 1 Global, coastal cities Without significant mitigation investments, flood risks due to sinking could cost coastal cities an estimated $635 billion per year by 2050.15,16Netherlands Infrastructure related: Buildings/other Damage to buildings and infrastructure from peat and clay soil subsidence is projected to reach €20 billion by 2050, of which €17 billion are in repair costs of structural damage. In Rotterdam and Gouda, property values are expected to decline by 7% and 6%, respectively.9,10 Mexico City, Mexico Infrastructure related: Metro system Subsidence has damaged parts of metro infrastructure, which serves four million passengers per day. Impacts include compromised brake safety, rail bending and heightened flood risk.13China Infrastructure related: Structural damages Total economic loss since 1950 due to subsidence is estimated at CNY 450–500 billion (Chinese yuan); direct losses due to structure and infrastructure damage reach CNY 0.8–1.0 billion per year.11 Beijing–Tianjin, China Infrastructure related: Railway Along the Beijing–Tianjin high-speed railway, subsidence-sensitive areas have been matched to maintenance and repair records, implying increased inspections and potential operational costs.14US Infrastructure related: Buildings Over 90 flood incidents since 2000 have occurred across eight cities experiencing sinking rates above 3mm per year. In urban areas, 29,000 buildings are located in high and very-high-risk damage areas.8 Maricopa County, Arizona, US Infrastructure related: Buildings Modelling from 2004 and 2010 indicates that home value depreciation averages 1.82% (approximately $5,229) in subsidence areas.12 Resilient Economies: Strategies for Sinking Cities and Flood Risks 6