Drenched New Orleans passes post-Katrina hurricane test

NEW ORLEANS, (Reuters) – Hurricane Isaac brought widespread flooding to the U.S. Gulf Coast yesterday, but elaborate defenses built to protect New Orleans after it was devastated by Hurricane Katrina seven years ago seemed to pass their first major test.

The huge, slow moving weather system, downgraded to a tropical storm on Wednesday, dumped massive amounts of rain to test new levees and flood containment systems and officials were careful not to declare a premature victory.

“This is a slow-moving storm and it is going to cause a tremendous amount of damage,” said Louisiana Governor Bobby Jindal, warning of another day of wind and rain ahead. Water flooded over the top of a levy on the outskirts of New Orleans and threatened to flood oil refineries and towns in the state and neighboring Mississippi. It looked, though, as if most energy facilities had escaped damage, and no deaths or serious injuries were reported.

While not nearly as strong as Katrina – a Category 3 hurricane on the five-step Saffir-Simpson scale when it slammed into New Orleans on Aug. 29, 2005 – authorities have warned repeatedly against underestimating Isaac.

Isaac slowed dramatically as it approached land and hugged the coast for hours before turning inland. This allowed it to take on more strength than many forecasters had expected, said Tim Doggett, the principal scientist at AIR Worldwide, a disaster modeling agency.

U.S. President Barack Obama’s top advisor on disaster response, said the storm downgrade was not grounds for complacency.

“There is no such thing as ‘just’ a tropical storm,” said Craig Fugate, director of the Federal Emergency Management Agency. “You have significant weather impacts still to occur.”

At 8 p.m. EDT (0000 GMT), Isaac was still only 60 miles (95 km) west of New Orleans, the National Hurricane Center said.

Isaac made landfall in southeast Louisiana on Tuesday afternoon as a Category 1 hurricane before crawling up the coast and toward New Orleans and Baton Rouge on Wednesday. It brought high winds, storm surges, and torrents of rain.

“The slow motion and large size of this system are making the impacts more severe and more wide ranging than some folks might have perceived would be the case,” said Rick Knabb, National Hurricane Center director.

The center said isolated maximum rainfall could reach 25 inches (64 cm) over much of Louisiana and parts of Mississippi and Alabama through Friday. A few spots in New Orleans already approached those totals.

New Orleans Mayor Mitchell Landrieu said the city’s flood defenses, strengthened since 2005 with a $14.5 billion system of walls, floodgates, levees and pumps, had done their job in the face of the torrential rain.

“The federal levee system … is fine,” he told local radio. “There are no risks. It is holding exactly as we expected it to and is performing exactly as it should.”

The storm taxed the city’s sewage system, though, prompting Landrieu to urge residents to “keep the flushing to a minimum.”

Tree limbs and street signs littered the streets on Wednesday, drainage canals filled with storm water and power was out in much of the city.

VENTURING OUT

After a night of hunkering down, some residents braved the winds and rain on Wednesday.