Like many people, I have seen a considerable amount of media coverage over the past couple of days on the 5th anniversay of Hurricane Katrina’s landfall on the Gulf coast. Katrina is firmly entrenched in history as one of the most devastating natural disasters in the United States. It is the costliest ($81 billion total damage estimate in terms of unadjusted dollars) and one of the five deadliest (over 1800 direct and indirect deaths) hurricanes to ever strike the U.S.
The above satellite image shows Katrina when it was a Category 5 hurricane the day before landfall on the Gulf coast. Some of the recent comments on Katrina have been primarily focused on the devastation in the city of New Orleans which is understandable. Much attention has been given to the levee failures which caused nearly 80% of New Orleans to be flooded. This was indeed a catastrophe. I have heard some say that everything went wrong that could have gone wrong.
But we need to be clear that Katrina would have resulted in a catastrophe even if the city of New Orleans had not flooded. The storm surge would still have inundated the Mississippi coast with highest values there between 24 and 28 feet. The storm surge would still have been 12 to 16 feet in St. Tammany Parish, 15 to 19 feet in eastern Orleans Parish, St. Bernard Parish and Plaquemines Parish. And let’s not forget that even the northern and western shores of Mobile Bay had 8 to 12 feet of storm surge.
Remember too that Katrina weakened from a Category 5 hurricane down to a Category 3 hurricane when it made Gulf landfalls over both Buras, LA and again near the LA/MS border on the morning of August 29th. The large size of the hurricane contributed to the extreme storm surge. And remember that the track of the center of Katrina only clipped southeastern LA and downtown New Orleans likely received only Category 1 and 2 winds. The strongest Category 3 winds were to the east of New Orleans. So when some folks imply that Katrina was the worst case scenario, that is not the case. One can only imagine what could have happened if Katrina had remained a Category 5 hurricane and the track shifted only slightly to the west giving the highest populated areas around New Orleans even greater impacts.