From October 1994:
New Orleans was spared, this time, but had it not been, Hurricane Ivan would have:
* 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.
Researchers have estimated that prior to a “big one,” approximately 700,000 residents of the greater New Orleans area (out of 1.2 million) would evacuate. In the case of Hurricane Ivan, officials estimate that up to 600,000 evacuated from metropolitan New Orleans between daybreak on Monday, September 13 and noon on Wednesday, September 15, when the storm turned and major roads finally started to clear.