Floods are the costliest natural hazard events in the United States in terms of lives and property losses. The financial costs of flood disasters are unsustainable, especially for the national government, which assumes the most costs while state and local governments have the greatest ability to avoid great losses due to their influence over land use, economic policy, and other areas that can help mitigate floods and reduce the high costs of relief and recovery. This article summarizes the types, causes, and occurrence of floods in the United States and their unsustainable economic and social costs. It explains that the growing burden to taxpayers from disaster response and recovery has resulted in increased interest by national decision makers in shifting more disaster responsibilities and costs to state and local governments. The article reviews the broad tool kit of mitigation strategies available to local governments and their residents in taking greater responsibility for the impacts of flood events.