New Orleans remains vulnerable
Congress plans to fix levees by 2011, ecologists, politicians want to restore wetlands
Howard Witt
Issue date: 9/11/08 Section: Nation & World News
POINT CELESTE, La. (MCT) - About 40 miles farther inland around the periphery of one of America's most vulnerable major cities, the U.S. Army Corps of Engineers is engaged in a furious $15 billion construction effort to rebuild the ring of concrete levees and steel floodgates that are supposed to protect New Orleans from catastrophic flooding when the next big hurricane blows ashore.
Last week, Hurricane Gustav, a Category 2 storm, punched a hole in that levee the length of two old Chevy sedans, flooding hundreds of acres of land and threatening a giant oil refinery nearby. Workers struggled for days to patch the breach with sandbags dropped from Army helicopters.
"This parish has 34 holes and weak spots in levees just like this, from Gustav and previous hurricanes," Billy Nungesser, the president of Plaquemines Parish, said last week as he directed the repair effort. "You will never be able to build levees high enough and wide enough in New Orleans if we keep losing ground down here."
To understand why New Orleans remains so vulnerable to huge ocean surges kicked up by storms like Hurricane Katrina in 2005, it helps to gaze across the Gulf of Mexico.
The open water didn't used to be there. As recently as a generation ago, lush wetlands filled
with grasses and plants and loamy muck spread out for dozens of miles. That provided a spongelike buffer zone that absorbed and dispersed the fierce pounding waves churned up by hurricanes long before they pushed giant walls of water farther north toward New Orleans.
Experts have even devised a calculation to measure that buffering phenomenon: Each 2.7 miles of coastal marsh reduces the surge from a tropical storm by one foot.
But decades of dredging the Mississippi River delta to keep it navigable, the vital waterway lies just a few hundred feet from this levee, diverted the natural deposits of sediments that once renewed the marshlands. Instead, the Army Corps dumps the sediment far out to sea.
Last week, Hurricane Gustav, a Category 2 storm, punched a hole in that levee the length of two old Chevy sedans, flooding hundreds of acres of land and threatening a giant oil refinery nearby. Workers struggled for days to patch the breach with sandbags dropped from Army helicopters.
"This parish has 34 holes and weak spots in levees just like this, from Gustav and previous hurricanes," Billy Nungesser, the president of Plaquemines Parish, said last week as he directed the repair effort. "You will never be able to build levees high enough and wide enough in New Orleans if we keep losing ground down here."
To understand why New Orleans remains so vulnerable to huge ocean surges kicked up by storms like Hurricane Katrina in 2005, it helps to gaze across the Gulf of Mexico.
The open water didn't used to be there. As recently as a generation ago, lush wetlands filled
with grasses and plants and loamy muck spread out for dozens of miles. That provided a spongelike buffer zone that absorbed and dispersed the fierce pounding waves churned up by hurricanes long before they pushed giant walls of water farther north toward New Orleans.
Experts have even devised a calculation to measure that buffering phenomenon: Each 2.7 miles of coastal marsh reduces the surge from a tropical storm by one foot.
But decades of dredging the Mississippi River delta to keep it navigable, the vital waterway lies just a few hundred feet from this levee, diverted the natural deposits of sediments that once renewed the marshlands. Instead, the Army Corps dumps the sediment far out to sea.
Be the first to comment on this story