Infrastructure for water, urban drainage and flood protection has a typical lifetime of 30–200 years and its continuing performance is very sensitive to climate change. Investment decisions for such systems are frequently based on state-of-the-art impact assessments using a specified climate change scenario in order to identify a singular optimal adaptive strategy. In a non-stationary world, however, it is risky and/or uneconomic to plan for just one climate change scenario as an average or best estimate, as is done with the use of the Predict-Then-Adapt method.