Many metropolitan areas such as Vicksburg, Miss., Memphis, Tenn., and St. Louis have long been situated at riverside points strategically valuable for trade and commerce. The surrounding countryside is flat for building and fertile for farming and has been cultivated for centuries.
"A lot of the homes that are damaged have been there for years," said Ed Sutton, senior vice president at the National Association of Home Builders. People "build them close to rivers because that was at one time the only means for transporting stuff up and down."
Sutton, whose organization represents home builders, argues that the laws are in place to ensure that homes built in flood plains are safe even when waters rise. Homes are required to be built above the 100-year flood plain and, in most cities, homeowners get a break on insurance for every feet their house is elevated above that level.
Yet that hasn't prevented the destruction of hundreds of homes every year, a casualty that Sutton argues is caused by Mother Nature, not builders or authorities who approve such developments.
"If you get a thousand-year flood or a freak hurricane that's more than that, you're going to have damage," he said. "It is like a large catastrophic earthquake. You can only design for a certain level of protection and still be economically feasible for any type of building."
FEMA is in the process of remapping U.S. flood plains and will likely expand the flood zones to increase the size of its insurance program.