Open Access

Marina Bier, Ramian Fathi, Christiane Stephan, Anke Kahl, Frank Fiedrich, Alexander Fekete

• In the response of the flood disaster in Germany 2021 a vast number of spontaneous volunteers (SVs) participated. They organized coordinating services, developed emergent forms of SVs and thus hold the potential to improve existing flood managing capacities. This raises the need for in‐depth knowledge about SVs and organization, the use of information and communication technologies (ICT), social and individual aspects. This article analyzed results of an online survey ( n  = 2636) with the aim to discuss challenges and potentials to develop SVs as social innovations in flood risk management. As a result, SVs are strong value‐based motivated, can be psychologically stressed and travel long distances, especially when they got aware of helping possibilities via social media. Disaster relief organizations rarely cooperate with or integrate SVs, but when they collaborate, SVs' satisfaction with authorities increases significantly. Based on the results, this article derives preplanning of useful concepts consider safety aspects, ICT utilization, foster mutual respect between SVs and authorities and supporting sense of community as key results for development of social innovations. Especially in light of pandemics, social crisis like refugee movements, and climate change‐related disasters, the requirement rises for engaging SVs.