It's almost as if the planning stopped at the flooding," said Craig E. Colton, a geography professor at Louisiana State University, wondering as many have at the lack of foresight.
Compounding the problem in New Orleans is that those with the least means to evacuate happen to live in the most flood-prone neighborhoods.

Colton - an expert on environmental justice - said that, historically, the poorest groups have lived in the low-lying areas, starting in the 1830s when well-off whites - and their slaves in some cases - built homes on higher ground near Mississippi River levees, while Irish immigrants lived near Lake Pontchartrain at sea level.

Since the 1890s, those lower areas have been largely African-American - most notably the 9th Ward, where the worst flooding occurred this week. Overall, the city is 67 percent black.
"There's a saying out West that water flows toward money, but in New Orleans it's really the reverse, that water flows away from money," Colton said.

And New Orleans is one of the nation's poorest cities, with some 30 percent below the poverty rate.