Population ~1 millionArea ~326km22.3 Rotterdam’s resilience: engineering a future on water Context Rotterdam, a port city situated in the low-lying delta of the Netherlands, is vulnerable to land subsidence. With significant portions of the city located below sea level, ongoing groundwater management is essential to maintain land for agriculture, industry and urban living. Its location renders subsidence a persistent challenge with surface water playing a key role in reducing sinking risk.117,118 Subsidence rates tend to be most pronounced in areas built on reclaimed land and peat soil. These conditions exacerbate flood risks, threaten infrastructure and accelerate saltwater intrusion. In response, Rotterdam has adopted strategies combining engineering, innovative urban design, policy measures and community engagement. Solutions The city employs a multi-layer approach to manage water and stabilize land. –National programmes: Rotterdam benefits from the Netherlands’ Delta Works Programme, including the Maeslant storm surge barrier, a system of dikes, locks and barriers that provide flood protection and mitigate subsidence.119 This programme is sustained by a policy foundation and an annual budget of €1.25 billion funded by the national government until 2032. In specific programmes, like the Freshwater Delta Plan, there are cost-sharing responsibilities between different government bodes. –Large-scale infrastructure: The 2013 Rotterdam Climate Change Adaptation Strategy and the Rotterdam Climate Initiative (RCI) have made water resilience central to spatial planning.120 The city’s adaptive network of canals, lakes, retention areas, pumping stations and sewer systems helps to address climate risks. Notable projects include the Museumpark underground water storage (10,000m3 capacity) and extensive green roof installation (over 185,000m2) to manage stormwater.121 These efforts help mitigate the consequences of subsidence. Resilient Economies: Strategies for Sinking Cities and Flood Risks 23

Resilient Economies Strategies for Sinking Cities and Flood Risks 2025