1479 What if Hurricane Ivan had hit New Orleans?

That scenario was examined in 2004 here.

Here's what was predicted:

Pushed a 17-foot storm surge into Lake Pontchartrain;

Caused the levees between the lake and the city to overtop and fill the city “bowl” with water from lake levee to river levee, in some places as deep as 20 feet;

Flooded the north shore suburbs of Lake Pontchartrain with waters pushing as much as seven miles inland; and

Inundated inhabited areas south of the Mississippi River.

Up to 80 percent of the structures in these flooded areas would have been severely damaged from wind and water. The potential for such extensive flooding and the resulting damage is the result of a levee system that is unable to keep up with the increasing flood threats from a rapidly eroding coastline and thus unable to protect the ever-subsiding landscape."

Many people chose not to evacuate during Hurrican Ivan. Here's why:

"The fact that 600,000 residents evacuated means an equal number did not. Recent evacuation surveys show that two thirds of nonevacuees with the means to evacuate chose not to leave because they felt safe in their homes. Other nonevacuees with means relied on a cultural tradition of not leaving or were discouraged by negative experiences with past evacuations."

What was learned after Hurricane Ivan about the able bodied non-evacuees?

"Residents who did not have personal transportation were unable to evacuate even if they wanted to. Approximately 120,000 residents (51,000 housing units x 2.4 persons/unit) do not have cars. A proposal made after the evacuation for Hurricane Georges to use public transit buses to assist in their evacuation out of the city was not implemented for Ivan. If Ivan had struck New Orleans directly it is estimated that 40-60,000 residents of the area would have perished."