America's Most Vulnerable Places: Midwestern Floodplains (Mississippi River Basin)
Credit: Scott Olson / Getty Images

Extreme storms have nearly doubled in the basin's seven Midwestern states since 2001. Years of housing construction and other development in the floodplain mean that the barrier that once protected towns and millions of people is largely gone. Bea's solution? HiDro Barriers: five-foot inflatable plastic walls that can withstand a 100-year flood. Short of that, Bea says, head for higher ground.