Integrated Environmental Assessment and Management — Volume 00, Number 00—pp. 1–10 Received: 29 July 2019 | Returned for Revision: 25 September 2019 | Accepted: 20 April 2020 1 Special Series Civil Society and Social Mobilizations in the Context of the Rio Doce Socioenvironmental Disaster Euzeneia Carlos*† †Federal University of Espírito Santo (UFES), Vitória, Espírito Santo, Brazil EDITOR'S NOTE: This article is based on work presented at the SETAC Fundão Dam Rupture Environmental Science Meeting in Brasilia, Brazil (26–27 June 2019) describing the scientific aspects associated with environmental recovery of the Mariana–Rio Doce river basin. ABSTRACT To explain how social movements and organizations changed in the context of the Rio Doce, Brazil socioenvironmental disaster, this article identifies a process of organizational innovation. The research is based on documental data and interviews with activists over the 3 y of the disaster. The main argument is that organizational innovation consists of changes in organizational forms and repertoires of collective action, based on existing organizational models and tactics. On the one hand, the innovation occurred through the territorialization of novel organizational forms, intermediated by social movements that act as incubators. On the other hand, it consisted of the combination among extrainstitutional, institutional, and multiscalar repertoires and in the innovation in tactics and performances. Mechanisms of adaptation, imitation, and negotiated diffusion are identified which operated in this innovation process. It is argued that the organizational innovation of social movements was propelled by political constraints of disaster governance, which pushed them to innovation, in addition to the role of preexisting organizations. Integr Environ Assess Manag 2020;00:1–10. © 2020 SETAC Keywords: Organizational innovation Repertoires of contention Civil society Fundão dam collapse Rio Doce disaster RESUMO Para explicar como os movimentos sociais e organizações da sociedade civil mudaram no contexto do desastre socio- ambiental do Rio Doce, este artigo identificou um processo de inovação organizacional. A pesquisa é baseada em dados documentais e entrevistas com ativistas ao longo dos três anos do desastre. O argumento principal é que a inovação organizacional consiste em mudanças nas formas organizacionais e repertórios da ação coletiva, com base nos modelos organizacionais e táticas disponíveis. Por um lado, a inovação ocorreu através da territorialização de novas formas organ- izacionais, intermediadas por movimentos sociais que atuaram como incubadoras. Por outro, consistiu na combinação entre repertórios extrainstitucionais, institucionais e multiescalares e na inovação nas táticas e performances. São identificados os mecanismos de adaptação, imitação e difusão negociada que operaram nesse processo de inovação. Argumenta‐se que a inovação organizacional dos movimentos sociais foi impulsionada por constrangimentos políticos da governança do de- sastre que os levaram à inovação, além do papel das organizações pré‐existentes. Integr Environ Assess Manag 2020;00: 1–10. © 2020 SETAC INTRODUCTION The present article examines obstacles to organizational change in civil society. Traditionally, civic organizations were conceived as resources of the collective action that facili- tates or restricts mobilization (McCarthy 2006). In theories of organizational change, the conservative tendency of bu- reaucratization, oligarchization, and cooption has also pre- dominated (McCarthy and Zald 1977). However, the incorporation of organizational innovation and culture in studies of organizational change has renewed this ap- proach, going beyond organization as a resource and the “iron law of oligarchy” (Clemens 1993, 2005). By investigating how social movements and organizations change in the context of an environmental disaster, the present study considers, in addition to the role of preexisting organizations, the political constraints imposed by disaster Integr Environ Assess Manag 2020:1–10 © 2020 SETAC DOI: 10.1002/ieam.4282 * Address correspondence to euzeneiacarlos@gmail.com Published 23 April 2020 on wileyonlinelibrary.com/journal/ieam. This article contains online‐only Supplemental Data.