Lake Pontchartrain

The northern edge of New Orleans is marked by Lake Pontchartrain, which is basically a very large, shallow bay connected to Lake Borgne and the Mississippi Sound east of the city. The worst-case scenario I had seen described (long before Katrina) was a slow-moving hurricane sending a 20+ foot surge into the lake and overtopping the levees. Katrina was different, with the strongest surge farther east and the levee failures occurring as much due to structural and foundation failures in the dikes as the sheer height of the surge. This suggests that the worst-case scenario might have been even worse than thought. I think what struck me about my wanderings in New Orleans was the sobering reality that as bad as Katrina had been, the future may bring worse.