Floods are the most destructive, most frequent and most costly natural disasters on earth. Flood damages have soared in recent decades, despite hundreds of billions of dollars spent on flood control structures. This is partly because global warming is causing more severe storms, and partly because of growing populations and economic activity on floodplains. It is also because flood control technologies and approaches often prove counterproductive. This report explains the failure of dams and levees to stop rising flood damages and describes better ways to tackle flood management.