This paper presents key findings from an ‘immersion’ that was undertaken in August 2017 on Paquetá and surrounding islands within the Amazon region of Brazil. In this research, immersion is understood as active participation in peoples’ lives over a period of time and supported by other methods including observation, semi-structured interviews and co-mapping. This research adapted the urban metabolism concept commonly used to assess levels of sustainability and resilience, for application to the context of peripheral river islands located in the Tocantins river near the Brazilian city of Belém. It specifically focuses on factors that impact on people’s behaviour in relation to water management, or what is described here as the ‘island water metabolism’. This includes geographic, seasonal, local governance and social dimensions as well as dependence on the rising and falling tides of the river.