Resilient Economies Strategies for Sinking Cities and Flood Risks 2025

Takeaways Rotterdam’s experience demonstrates that urban resilience is an ongoing, adaptive process requiring evidence-based knowledge, agility and collaboration. Key lessons for cities and stakeholders worldwide include: –Integrated planning: Addressing flood risks linked to land subsidence and the climate crisis requires adopting and integrating various solutions rather than isolated interventions. Rotterdam demonstrates the value of combining large and small-scale infrastructure, urban planning and design, regulatory and legal frameworks and community engagement for continuous adaptation. Such an approach can create opportunities for multistakeholder collaboration within an interconnected ecosystem. –Governance and sustained investment: For governments, Rotterdam’s approach highlights the need for legal frameworks and dedicated budgets. For the private sector, it signals the importance of understanding subsidence and flooding challenges related to urban planning and infrastructure development, management and expansion. –Adaptability in a changing climate: Complete elimination of subsidence and flood risks may not be possible due to unique geological conditions, and especially as climate change accelerates sea-level rise and extreme weather events. Continuous monitoring, scenario analysis and adaptive management are critical. Both governments and businesses should embed flexibility into their strategies to respond to evolving subsidence and climate conditions. Rotterdam flood risk map, 2100 FIGURE 7 Flood risk map – 2100 The risk map depicts the areas where it is expected that water storage deficits will occur in the future, and where unequal subsidence makes the area more vulnerable to the effects of intensive rainfall. These are mainly areas that are built on peat. Furthermore, the map shows the bottlenecks: the sewer system, groundwater and low-lying infrastructure such as tunnels. Current water storage deficit areas (NBW – National Water Agreement) -0.1–0.5 0.5–1 >1Water issues Subsidence (cm/year) Bottleneck sewers Bottleneck flooding due to groundwater City centre with considerable consumer pressure on the open spacesBottlenecks and vulnerable areas Urban area with little open space Urban area with much open space Low-lying infrastructure Source: Rotterdam Climate Initiative. (2013). Rotterdam Climate Change Adaptation Strategy. https://www.urbangreenbluegrids.com/uploads/RCI_-RAS_UK_-DEF.pdf Resilient Economies: Strategies for Sinking Cities and Flood Risks 25