As floodwaters make their way down the Mississippi, officials are concerned about potentially devastating levee breaches in New Orleans that could inundate Uptown if the Morganza spillway is not opened, according to reporting by Mark Schleifstein of the Times-Picayune.
“We have a good bit of experience dealing with seepage and sand boils, saturated soil conditions when the river stages are around 17 feet,” Bob Turner, executive director of the Southeast Louisiana Flood Protection Authority-East, told the newspaper. “Once the river gets over 17.5 feet, I don’t know that we’ve got a lot of experience dealing with those same issues. Seepage and sand boils, that uncertainty gives us some concern. My gut is if it gets higher, it’s going to be more difficult to keep those things under control.”
The river had already reached its official flood stage of 17 feet in New Orleans by Monday evening, where it is predicted to hold through the week and then gradually rise to 17.5 feet over the weekend, according to the National Weather Service. Floodwalls are built to withstand 20 feet of flooding, and the river has not crested above that level since the Great Flood of 1927, historical data shows.
Morganza is widely expected to be opened, but if it is not, worst-case scenario maps of levee failures in New Orleans show flooding of 10 to 20 feet in Uptown neighborhoods, worse than the breaches after Hurricane Katrina caused, the newspaper reports.