Storm Barry may overtop New Orleans levees

Today in the Gulf of Mexico, the upcoming storm, Invest 92L, is projected to evolve into a depression and then a tropical storm or hurricane (they will call it Barry) before heading west toward Louisiana and Texas.

If Barry proceeds the way storm watchers project it will, it will create an unprecedented situation in New Orleans: a cyclone-driven storm surge up a river already swollen from months of flooding. The surge could lift the water in the Mississippi River nearly to the top of the levees. At 19 feet above sea level, it would be the highest crest for the river in New Orleans since 1950.

The Mississippi River at New Orleans is currently at 16 feet. The floodwalls that protect New Orleans were raised to 20 feet after Hurricane Katrina, so a surge of 3 feet or so will not overtop the retaining walls and flood New Orleans.

The New Orleans forecast includes a surge to 19 feet, one foot below the top of the levees.

But, in a quote to Slate magazine, David Ramirez, chief of water management for the U.S. Army Corps of Engineers’ New Orleans District, warned: “The levees protect the city up to 20 feet, but 19 is close and doesn’t include waves splashing up and so on. It’s too close for comfort for us. And that surge could be more or could be less. If things change and it gets higher, at some point, there’s only so much we can do.”

New Orleans at the Carrollton gauge.
(USACE photo)

The peak of the threat will come Friday when the surge is expected to hit. The area in the greatest danger is Riverbend where the levees are the oldest and most vulnerable.

“We’re planning for the worst, hoping for the best,” Corps spokesman Rickey Boyett told NOLA.com. “But what we don’t want is for residents to hold off on their own preparations. Now is the time to make sure they have everything in order.”