Worldwide, water governance is facing pressing challenges due to climate change. This thesis uses evolutionary agent-based models and field experiments to analyzes under what conditions, and with which institutional mechanisms cooperative arrangements can be established and maintained under climate change. Results show that show that social norms of cooperation may collapse in times of resource scarcity, and the dynamics are mediated by inequality and heterogeneity of users. Further, both modelling results and field experiments conducted in Cambodia suggest that existing institutions may respond to scarcity and vice versa. In addition, when two communities share water as a common-pool resource and infrastructure as a public good, the level of cooperation in both communities depends on social structure and characteristics that enable learning within and across communities. Finally, the experimental findings suggest that having experienced scarcity in the past may create public support for institutional change.