This chapter focuses on water planning in a changing world in which humans and nature are inextricably linked. It aims to provide protected area (PA) authorities with some of the main considerations when planning for the protection of freshwater ecosystems and associated biodiversity. The chapter targets PA authorities at the operational level of individual PA, as well as PA systems managers with a more national or international focus. It begins by outlining some emerging water management approaches in which water planning can be embedded, explaining some of the 'resilience principles' that they have in common. The chapter describes key freshwater considerations that should be incorporated into planning within PAs. It discusses the role that PA authorities can play in ensuring that the outputs from these assessments inform and shape water planning processes, and the opportunities these perspectives provide for re-imagining the future role of PAs in the Anthropocene.