Room for Sea-Level Rise: Conceptual Perspectives to Keep The Netherlands Safe and Livable in the Long Term as Sea Level Rises

An accelerated sea-level rise (SLR) may threaten the future livability of the Netherlands. Three perspectives to anticipate this SLR are elaborated here regarding technical, physical, and spatial aspects: Protect, Advance, and Accommodate. The overall objective was to explore the tools and measures that are available for adaptation, assess their spatial impacts, and identify dos and don’ts in current spatial issues like housing, climate adaptation, infrastructure, and the energy transition. Each elaboration was performed by a consortium consisting of representatives from private parties (engineering consultancy, project contractors, (landscape) architects, economists), knowledge institutes (including universities), and government, using an iterative process of model computations and design workshops. The elaborations made clear that a realistic and livable future perspective for the Dutch Delta continues to exist, even with a maximum analyzed SLR of 5 m, and will consist of a combination of elements from all three perspectives. This will require large investments and space for new and upgraded water infrastructure and will have large impacts on land use, water availability, agriculture, nature, residential buildings, shipping, and regional water systems. There is still a significant degree of uncertainty regarding future SLR; therefore, it is not advisable to make major investment decisions at this time. Nevertheless, some no-regret measures are already clear: continuation of the protection of the Randstad agglomeration (Amsterdam, The Hague, Rotterdam, and Utrecht) and its economic earning potential for future generations, adaptation of agriculture to more brackish and saline conditions, designation of space for additional future flood protection, extra storage capacity (for river discharge and increased precipitation), river discharge, and sand extraction (for future coastal maintenance). The research identified concrete actions for today’s decision-making processes, even though the time horizon of the analysis captures centuries. Including the perspectives in long term, policy planning is already necessary because the transition processes will take decades, if not more than a century, to be implemented.