ABSTRACT. Adaptation to climate change can be an inclusive and collective, rather than an individual effort. The choice for collective arrangements is tied to a call for solidarity. We distinguish between one-sided (assisting community members in need) and two-sided solidarity (furthering a common interest) and between voluntary and compulsory solidarity. We assess the strength of solidarity as a basis for adaptation measures in six Dutch water management case studies. Traditionally, Dutch water management is characterized by compulsory two-sided solidarity at the water board level. Since the French times, the state is involved through compulsory national solidarity contributions to avoid societal disruption by major floods. In so far as this furthers a common interest, the contributions qualify as two-sided solidarity, but if it is considered assistance to flood-prone areas, they also qualify as one-sided solidarity. Although the Delta Programme explicitly continues on this path, our case studies show that solidarity continues to play an important role in Dutch water management in the process of adapting to a changing climate, but that an undifferentiated call for solidarity will likely result in debates over who should pay what and why. Such discussions can lead to cancellation or postponement of adaptation measures, which are not considered to be in the common interest or result in an increased reliance on local solidarity.