Floods are the costliest disasters in American history-and today, floods are getting both worse and more common. As flooding becomes ever more salient one might expect that public support for flood prevention and mitigation policies would grow, yet we see significant opposition to a wide range of flood policies. We find, across four samples and a range of study designs and measurement strategies, that citizens are more likely to oppose flood mitigation policies when they think the policy in question will harm someone's property rights. This finding has important real-world implications, as many policy proposals aimed at addressing flood disasters, including approaches as diverse as floodwater diversion and elimination of flood insurance subsidies, can infringe on property rights and interests. This study highlights one tension in addressing flood policy in democratically acceptable ways, and also the important effects that framing can have on mass support for flood mitigation policies.disaster planning and preparedness, disaster recovery, risk policy and management © 2021 Policy Studies Organization insurance, and many billions more are spent on recovery and rebuilding. Since October of 2018, there have been six major events in the United States involving severe storms that included flooding, and each exceeded $1 billion in costs each (NOAA National Centers for Environmental Information [NCEI] U.S. Billion-Dollar Weather and Climate Disasters, 2018). As the perils of flooding become ever more salient we would expect that public support-even demand-for these programs would grow. Surprisingly, though, large swaths of the public are intensely opposed to many of these policies, including mapping flood plains and restructuring the National Flood Insurance Program (Pralle, 2019;Strother, 2018).In this article, we examine public opposition to common flood mitigation policies currently in use in the United States. Drawing on data from four original surveys, including two that are representative and two with embedded experiments, we argue that that citizens are much more likely to oppose flood mitigation policies when they think that the policy in question will harm someone's property rights. This finding has important real-world implications, as many policy proposals aimed at addressing flood disasters, including approaches as diverse as floodwater diversion and elimination of flood insurance subsidies, can infringe on the rights of property owners. This study also highlights an important tension in working to develop flood policy in democratically legitimate ways.