Writing for our “Chancing the Storm” series, Robert Soden discusses the multiple meanings and uses of “uncertainty” in understanding floods and people’s responses to information about them. Building on extensive research on the design of floodplain maps in Colorado that declare some places, but not others, at risk, Soden argues the techno-science understanding of uncertainty that these maps represent is important but limiting. To supplement this perspective, he calls for imagining uncertainty as productive (“generative”) and as socially and politically structured (“systematically produced”), drawing on examples from the floodplain mapping project.