<p>This study investigates how residents of flood-prone slum areas of Indonesia construct and maintain wellbeing in the face of recurring environmental threats. Current wellbeing research often rests on component-based approaches that may under-represent the socially and culturally constituted nature of wellbeing in non-Western contexts. Drawing on White’s (2010, 2015) relational wellbeing framework, we adopt a sequential mixed-methods design combining a quantitative survey of 700 respondents across three flood-affected Indonesian cities, Bima (<i>n</i> = 200), Pontianak (<i>n</i> = 300), and Manado (<i>n</i> = 200), with 37 in-depth qualitative interviews in the same locations. Within an abductive analytical strategy, qualitative material is applied to contextualize, interpret, and at times complicate the quantitative patterns, producing a culturally grounded yet comparable account of wellbeing. Principal Component Analysis yields eight wellbeing dimensions – Conviviality, Economic Resilience, Local Support System, Religiosity, Self-Competence, Security, Empowerment, and Reference Dependence – of which conviviality, economic resilience, and religiosity carry the highest factor loadings. Despite physical vulnerabilities, residents often remain in flood-prone areas, where strong social bonds, place attachment, and mutual support sustain wellbeing. Assuming dimensions are synergetic, we identify the most limiting dimension, the ‘binding constraint,’ per location and socio-demographic group, treating this as a diagnostic heuristic for policy prioritization rather than a causal claim. Conviviality, empowerment, and security emerge as distinct binding constraints across the three cities, showing that no single policy template fits all. The findings offer entry points for context-sensitive interventions and underscore the inseparability of wellbeing and resilience in vulnerable urban communities.</p>