The Soaking Surge Versus The Splintering Surge: What Will Be Learned?

Glenn links to a post today from Brendan Loy:

It is true, as some have pointed out in comments, that Katrina was not "likely" to hit New Orleans as of Saturday morning, or even Sunday morning for that matter. New Orleans was the hurricane's most likely target -- it remained in the crosshairs of the official forecast track all weekend -- but in terms of statistical strike probabilities, even the most likely target at 24-48 hours out still has a less-than-50% chance of getting hit, thanks to the uncertainties inherent in hurricane forecasting. However, given the technology that we currently have, you simply could not have a greater threat to a specific location, 48 hours before landfall, than the threat that New Orleans faced on Saturday morning. It was, as I said, a "high-confidence forecast," and one with enormously catastrophic potential. Thus, if an evacuation was not appropriate then, then it follows that an evacuation must never be appropriate at 48 hours. And that can't be, because really, 48 hours is already too late; studies have long shown that it would take 72 hours to completely empty the city of New Orleans. So unless the city's hurricane strategy was to throw up its hands and say, "there's nothing we can do," a mandatory evacuation -- school buses and all -- was most certainly called for on Saturday morning. As I wrote on Saturday afternoon, "If you knew there was a 10 percent chance terrorists were going to set off a nuclear bomb in your city on Monday, would you stick around, or would you evacuate? That's essentially equivalent to what you're dealing with here. I sure as hell would leave."

Finally, one last point. As horrible as the catastrophe has been, please realize that it actually could have been far worse. What occurred was not the long-feared "worst-case scenario," which involved not a levee breach equalizing the water level in Lake Ponchartrain and "Lake New Orleans," but rather a storm surge over-topping the levees and causing the water level in "Lake New Orleans," hemmed in by the still-intact levees, to rise substantially higher than the water level in the lake. If the storm had wobbled a meteorologically insignificant 20 or 30 miles to the west, and/or had not weakened from a Category 5 to a Category 4 at the last minute, that scenario would have occurred, and instead of a slowly developing 10-20 foot flood, New Orleans would have suffered a rapidly developing 30-40 foot flood. (Jackson Square would have been underwater, whereas in the real-world scenario it remained high and dry.) The whole thing would have happened Monday morning, and at the same time as the city was rapidly and massively flooding, the devastating winds that demolished the Mississippi coastline would have been tearing New Orleans apart instead. All of those attics where people took shelter would have been either submerged or shattered to bits. The French Quarter would have been swamped, instead of mostly surviving the flood. Second-floor generators in hospitals might well have drowned. Bottom line, there would be a lot fewer refugees and a lot more corpses.

I alluded to this worst case in my "Intent on Burying Drowning the Lede Leader" post. I also pointed out that even IF the Cat 5 flood walls HAD ALREADY BEEN BUILT they would not have stopped the current form of the disaster (the "soaking surge scenario") -- even though what we are seeing now is not actually the worst case that could have happened NOW given that there are no Cat 5 walls yet (the "splintering surge scenario").

As my modified graphic from the May 2005 Popular Science points out, the location of the levee breaks (indicated by the red rectangle added by me) was NOT where the Cat 5 levees were projected to be built (the red line separating NOLA from the Gulf to the right):

(Note that this graphic is not available in the on-line article at PopSci -- only in the print version)

So the the only way to avoid what just happened would have been to have spent the (probably) billions of dollars it would have taken to upgrade EVERY LEVEE IN THE NOLA AREA to Cat 5 levels!

And even then -- and assuming perfect engineering and flawless levee construction virtually throughout -- if the hurricane had shifted 20 miles to the west NOLA would be a lot less flooded but still be looking nearly as splintered as Mississippi looks like right now and likely with a still awful loss of life.

As Brendan highlights -- and I pointed out in my post -- the only way to avoid serious loss of life was to get everyone out of there in the first place.

Including the use of these now useless buses:


The "hurricane sensationalism" of the media and its creation of a Chicken Little mindset dulling the urgency of evacuation needs as much examination as what could have been done to physically protect NOLA.