In many sandy coastal areas, such as The Netherlands, sand dunes form a natural defense against flooding. Dune growth and preservation largely depend on the balance between marine erosion and sand input by wind, so sea-level rise and climate change might have consequences for flood protection. Our modelling results indicate that sea-level rise indeed increases erosion, but also that, up to a certain limit of rise, dunes are able to respond in a way that preserves their height and consequently their protective function. Simulations with reduced vegetation growth due to drought reveal a critical rate growth. If reduced below this limit, the dune’s ability to recover after storms declines. Although dunes can maintain themselves under moderate sea-level rise and drought, sand nourishments are required for preservation in developed areas.