Water is the lifeblood of planetary health and human civilisation. As a critical source of fresh water, rivers underpin civilisations, past and present. However, rivers constantly change in response to environmental and human pressures. Protecting global river systems from climate change and other anthropogenic activities (e.g., mining, pollution, dam construction), and understanding the interactions with human health (e.g., through the spread of water-borne and infectious diseases) has become a critical concern.