Climate education in elementary grades offers a chance to teach climate science, to help students understand how serious climate change is, to focus on ecosystems and global social systems, and to work toward justice-oriented solutions. This article describes the work of nearly 70 fourth grade bilingual students, their teachers and librarian, and support from multiple community volunteers to investigate persistent problems of flooding in local waterways. Children did not study flooding as an abstract concept; instead, they approached their study of flood mitigation as civic actors whose research and voices matter for shaping public policy for their community. Over the course of a school year, children worked with teams of educators and community volunteers in a weekly science and civic engagement unit focused on connecting with the waterways and ecosystems that experience frequent and sometimes devastating flooding. During this unit of study, children made sense of flooding, the role that adaptation and mitigation can play in resilient responses to climate change, and the role that their voices can play as civic actors whose input is meaningful for shaping civic decisions not in the future as adults but now as children who have a stake in how their community functions.