Although the mobilization of pre‐existing networks is crucial in psychosocial resilience in disasters, shared identities can also emerge in the absence of such previous bonds, due to survivors sharing a sense of common fate. Common fate seems to operate in sudden‐impact disasters (e.g., bombings), but to our knowledge, no research has explored social identity processes in “rising‐tide” incidents. We interviewed an opportunity sample of 17 residents of York, United Kingdom, who were involved in the 2015–2016 floods. Using thematic and discourse analysis, we investigated residents' experiences of the floods and the strategic function that invocations of community identities perform. We show how shared community identities emerged (e.g., because of shared problems, shared goals, perceptions of vulnerability, and collapse of previous group boundaries) and show how they acted as a basis of social support (both given and expected). The findings serve to further develop the social identity model of collective psychosocial resilience in rising‐tide disasters. Implications for policy and practice are discussed.