Thicker Than Water?

On Thursday morning, assessment teams from the U.S. Army Corps of Engineers fanned out along the banks and bridges of the Industrial Canal in the eastern part of New Orleans, the waterway that had proved to be the weakest link in the city's storm defenses during Hurricane Gustav. Officials had watched anxiously as water surged into the channel, lapping perilously near the top of the floodwalls and sometimes pouring over into the adjoining neighborhood of Gentilly Woods. The engineering teams were scrutinizing levee walls and floodgates to determine the extent of the damage. "Here, you can see there was some scouring," said Randy Cephus, a corps public-affairs officer, pointing to an area at the foot of one floodgate where the rush of water had eroded the soil. Elsewhere, chunks of floodwalls were missing—they'd been struck by barges that had come unmoored during the hurricane (though they lay within another layer of floodwalls that remained unharmed).

The Industrial Canal's weaknesses highlighted just how vulnerable New Orleans remains. Granted, there was plenty to be thankful for in the wake of the biggest storm to hit the city since Hurricane Katrina three years ago. The evacuation proceeded smoothly, resources materialized quickly and the city's protective barriers kept flooding to a minimum. But Gustav was hardly the meanest storm that could have been unleashed on the city. It made landfall 70 miles away as a downgraded Category 2 storm (winds of 96 to 110 miles per hour), resulting in gusts of no more than 65mph in the Big Easy. Given that the city nevertheless came close to suffering another big flood, Gustav served as a reminder of the gaps in New Orleans's defenses and the susceptibility of its citizens in the lowest-lying areas. "Bottom line," says Ed Link, who led a post-Katrina investigation into the levee failures for the corps, "New Orleans dodged the bullet with the help of the hard work that everyone has accomplished since Katrina, but much remains to be done."

The corps has certainly made progress. It has repaired or restored 220 miles of levees and floodwalls in the New Orleans area. It has built floodgates to seal off three drainage canals from Lake Pontchartrain, which during Katrina surged through those waterways and flooded the city. And it has installed massive pumps along those canals that can suck out water at a rate that would empty an Olympic pool in seconds. The canal upgrades were put to the test during Gustav, and they performed well. Two of the floodgates were closed, blocking off the lake, and the pumps ensured that water in the canals didn't overtop the levees. As the corps put it in a recent report, "the New Orleans area now has the best flood protection in its history."

But Gustav also underscored the system's weaknesses. Unlike the three drainage canals, the Industrial Canal lacks floodgates at its meeting point with Lake Pontchartrain. It's also connected to two manmade channels--the Mississippi River Gulf Outlet (nicknamed "Mr. Go") and the Gulf Intracoastal Waterway--that proved disastrous during Katrina, funneling water from the Gulf and a nearby lake toward the heart of New Orleans. Moreover, the corps has replaced and raised only portions of the Industrial Canal's floodwalls, such as the stretch that gave way during Katrina and flooded the Lower Ninth Ward. The section that looked shakiest during Gustav was one that had only been reinforced, not raised. In Link's view, Gustav "dramatically demonstrated" the need to erect barriers to prevent the lake and gulf waters from gushing into the Industrial Canal.

Indeed, that's part of the corps's future plans. Among the remaining projects it envisions to help shield New Orleans: the closure of Mr. Go, the construction of a two-mile-long barrier at the confluence of Mr. Go and the Gulf Intracoastal Waterway to impede a storm surge, and the erection of a barrier where the Industrial Canal meets Lake Pontchartrain. To complete all of these plans and others, the corps has secured funding of about $14.6 billion. The result, it assures, will be to protect New Orleans against a so-called 100-year flood event—one with a 1 percent chance of occurring in a given year. The government currently estimates that it will finish all of this by 2011, though the end date has been repeatedly pushed back.

Not everyone is confident that the corps will pull it off. After all, these are the folks who brought New Orleans such catastrophic creations as Mr. Go in the first place. Critics like H. J. Bosworth Jr., a civil engineer and research director for the watchdog group Levees.org, blame previous levee failures on the corps's shoddy construction, including the use of unstable soils. And Robert Bea, an engineering professor at the University of California, Berkeley, who led an independent investigation of the levee failures after Katrina, questions the wisdom of corps projects like the surge barrier planned for the Intracoastal Waterway. Dutch and Japanese engineers, who are at the cutting edge of flood protection, "wonder what we are thinking or if we are really thinking," Bea wrote in an e-mail to NEWSWEEK. "We are clearly out of step—behind—parts of the world that have struggled with keeping water friendly for more than 2,000 years."