Public participation is the democratic gateway to more just, inclusive, and resilient communities. However, infrastructure and hazard mitigation planning tends toward top-down, expert-driven processes that fail to meaningfully include communities most at risk of disasters. In this article, we critically examine the potential of citizen science in infrastructure and hazard mitigation planning with a focus on stormwater infrastructure and extreme wet-weather events, as floods are the most common disaster in the US. We review literature on various citizen science approaches, from crowdsourcing to community science, and offer a framework that situates them within Sherry Arnstein’s foundational piece on public participation, a “Ladder of Citizen Participation.” We discuss the opportunities different participatory methods offer for meaningful public involvement, knowledge generation, and ultimately community control and ownership of stormwater and flood infrastructure. We provide case study examples across the US of how public works departments, emergency management, and related organizations have engaged communities around hazard risks and flooding challenges, and offer recommendations for how these programs can be improved. We conclude that in order to produce data needed to mitigate flood disasters and increase trust and public interest in infrastructure needs, civic participation should be grounded in community science, utilizing a multimedia and technological platform. The methods applied and data generated can be leveraged toward public safety, and provide voice, agency, and power particularly to disenfranchised communities most at risk from current hazards and looming climate change impacts.