New Orleans flood defenses hold, 16 years after Katrina failure

New Orleans, still scarred by the devastation wrought 16 years ago by Hurricane Katrina, held its breath as Ida bore down this week. But this time, the city's flood defenses prevailed.

In the wake of the 2005 storm that killed over 1,800 people and submerged whole swaths of New Orleans, the US government spent $14.5 billion on levees, pumps and other protections for the city and nearby suburbs.

"Ida came onshore with everything that was advertised: the surge, the rain, the wind," Louisiana governor John Bel Edwards told a briefing Monday.

"The good news, first, is all of our levee systems... performed magnificently," he added.

Located at the mouth of the Mississippi River and in an area below sea level, New Orleans is surrounded by water, with the giant, briny Lake Pontchartrain to the north and the Gulf of Mexico to the south.

Given the city's geography, as well as Ida's lashing 150-mile (240-kilometer) per hour winds, storm surge and heavy rains, the danger to New Orleans' 390,000 people was very real.

But no levee in the city was breached or overtopped. Edwards said that feat could be traced to 16 years ago.

Under the battering from Katrina's flood waters, more than 50 levees broke and 80 percent of the city was submerged, with water reaching 20 feet (six meters) in places. Billions of dollars in damage was done.

The storm and the failed response that followed unleashed suffering that was captured in images of desperate people stranded on the roofs of their flooded homes in sweltering heat, violent looting and fetid evacuation sites.

Authorities from then-president George W. Bush on down faced ferocious criticism, and since then New Orleans' flood-protections have been rebuilt and improved.

The system "performed as it was designed, that is, to keep water out of the city," said Rene Poche, spokesman for the Army Corps of Engineers in New Orleans, which was responsible for designing and building the levee system.

• 'You may be next' -

After Katrina, a 130-mile ring of barriers was built to withstand a storm surge of up to 30 feet.

Huge gates now allow water to drain away to Lake Ponchartrain or the Gulf of Mexico, while preventing water from entering the city, said Poche.

The protection system also includes more than 70 pumps, which drain water in the event of street flooding.

"After Katrina... it was important that the system was structurally superior -- higher levees, higher wall and resilient," he added.

The levees in Louisiana's largest city had already passed an initial test during Hurricane Isaac in August 2012, which caused little damage.

But some neighboring cities weren't so lucky this week, as Ida roared ashore as a ferocious Category 4 storm.

In LaPlace, west of New Orleans, roads and homes were submerged under Ida's floodwaters.

Ida has since lost strength and is now continuing northeastward as a tropical depression.

"Hurricane Ida's lesson, therefore, is not that Louisiana's storm protections are good enough. Its lesson is that investments in infrastructure save lives," historian Andy Horowitz wrote in a New York Times guest essay.

"Demand that Congress take meaningful action, because Louisiana is not unique, and you may be next," he tweeted Tuesday.