Perspective: Mississippi River: Friend or foe?What If a Hurricane Pushed a Surge up an Already High Mississippi River? No One Is Certain.
The Mississippi River has always been the lifeblood of New Orleans. It’s the reason for the city’s existence, and an awe-inspiring if sometimes forgotten feature of its landscape. One thing it hasn’t been, at least in recent memory, is a threat. That is, until this month, when wary residents caught a glimpse of the old Mississippi, a face of the river that’s been hidden since it was almost completely caged by man nearly a century ago. The compliant river had become a beast scaling its walls.
The Mississippi River has always been the lifeblood of New Orleans. It’s the reason for the city’s existence, and an awe-inspiring if sometimes forgotten feature of its landscape. One thing it hasn’t been, at least in recent memory, is a threat.
That is, until this month, when wary residents caught a glimpse of the old Mississippi, a face of the river that’s been hidden since it was almost completely caged by man nearly a century ago. The compliant river had become a beast scaling its walls.
Mark Schleifer and Jeff Adelson write in NOLA that Hurricane Barry turned out to be little more than an inconvenience in New Orleans, but its long, stutter-start approach to the Louisiana coast laid bare a reality the city has not had to confront since the epic flood of 1927 threatened to swamp it.
Since then, city residents have feared their fate would be determined by storm surges out of Lake Pontchartrain and the Gulf of Mexico, and they focused on the barriers built to keep them at bay, paying little attention to the possible threat from the waterway that gave the city life. That mindset was reinforced when Hurricane Katrina’s surges overwhelmed New Orleans’ sea-facing defenses.
Barry’s approach came as the Mississippi reached 16 feet above sea level in New Orleans, held back by levees whose lowest sections rise only about 4 to 6 feet higher.
The strongest surges moving upriver during past hurricanes have raised water heights between the levees by as much as 12 feet, raising the frightening possibility that the Mississippi could spill over its levees and floodwalls and flood the city — if not during Barry, then in a future storm when the river was already high.
The anxiety over what would happen to that swollen river during a hurricane, and the fear that such an unprecedented event could become more common because of either a changing climate or human tinkering with the river, has prompted calls for more studies into what had once been thought a remote possibility.
