Climate change-related flooding and sea-level rise have important direct and indirect health effects. In order to support health and equity, adaptation responses require collaborative, transdisciplinary learning and consensus-building, across a wide range of local-level stakeholders. We aimed to co-develop a shared understanding of the complex interplay between health, health determinants, flooding, and sea-level rise in a low-income urban area of Aotearoa New Zealand, to inform action.

We used qualitative participatory system dynamics modeling, involving interviews and group workshops with transdisciplinary stakeholders. We developed a shared set of wellbeing outcomes and triangulated participants’ knowledge with published evidence to develop a set of causal loop diagrams (CLDs). These capture the system feedback behavior between flooding and sea-level rise, and local health and wellbeing.

Thirty-three participants were involved across the project, identifying 22 wellbeing outcomes. The CLDs covered six intersecting themes: community-led development and participation in decision-making; quality of housing; the housing market; the insurance market; economic effects of flooding and sea-level rise; and access issues arising from flooding. Intervention points were identified, with the potential to inform health equity-focused adaptation policy. The process supported shifts in participants’ mental models towards consensus and effective intervention points, and transdisciplinary relationship-building.

Participatory systems modeling approaches may support cross-sector collaborative learning about the complex, dynamic influences on health and wellbeing in the context of local climate change adaptation. These shared, holistic understandings are essential to inform decision-making that promotes positive health and social equity outcomes.