Flooding from Hurricane Isaac was severe in Plaquemines Parish, La. (Carolyn Cole, Los Angeles…)
NEW ORLEANS — On the seventh anniversary of Hurricane Katrina on Wednesday, this city absorbed a rough reminder of the Gulf Coast's vulnerability as big, slow Hurricane Isaac delivered a punishing but less powerful blow than its catastrophic predecessor.
The massive storm lingered all day, lashing the coast with torrential rains and hurricane-force winds. Flooding was widespread from New Orleans through Mississippi and Alabama as downed trees and power lines left more than 600,000 customers without electricity.
An upgrade of New Orleans' 133-mile flood-control system largely withstood the deluge, but to the west, St. John the Baptist Parish was inundated by storm surge from Lake Pontchartrain and Lake Maurepas. Gov. Bobby Jindal said Wednesday night that officials had evacuated about 1,500 people and had about that many to go.
PHOTOS: Isaac lashes Gulf Coast
Elsewhere along Lake Pontchartrain, 60 people were rescued from a flooded area of St. Tammany Parish, said Christina Stephens, spokeswoman for the Governor's Office of Homeland Security and Emergency Preparedness.
And in isolated Plaquemines Parish, where Isaac came ashore Tuesday night, floodwaters spilled over part of a locally maintained 81/2 -foot-high levee, putting parts of the sparsely populated area under 12 feet of water. More than 100 residents were rescued by a flotilla of police, National Guardsmen and volunteers.
Most of those trapped had ignored a mandatory evacuation order issued Monday for Plaquemines, located on a finger of land that juts south of New Orleans and is bisected by the Mississippi River. On Wednesday, authorities ordered a mandatory evacuation for about 3,000 people protected by an 8-foot levee along the river's west bank, south of Belle Chasse, Jindal said.
MAP: The path of Isaac
For all the flooding and dislocation, Isaac was nothing like Katrina, in part because local and federal officials had learned from the 2005 catastrophe. Emergency efforts were much better coordinated, most residents were evacuated in good order and the revamped flood-control system held up. Statewide, at least 7,700 people have been evacuated, Stephens said.
Even with relentless rain, Isaac lacked Katrina's catastrophic maximum 28-foot storm surge and 125-mph winds. Katrina, a strong Category 3 hurricane when it came ashore, caused more than 1,800 deaths, mostly in Louisiana. By Wednesday night, there were no reports of deaths directly attributable to Isaac.
The storm made landfall as a Category 1 hurricane with maximum sustained winds of 80 mph and a storm surge of 6 to 12 feet. It was downgraded to a tropical storm Wednesday afternoon, as the rain and wind continued, floodwaters rose and tornado warnings were issued. By 10 p.m., the storm's sustained winds had dropped to 60 mph.
The National Hurricane Center warned that "life-threatening hazards from storm surge and inland flooding are still occurring."
Isaac was expected to lumber through Louisiana overnight and into Thursday, passing into Arkansas on Thursday evening. The hurricane center warned of rainfall accumulations of up to 25 inches, and reported that 22.5 inches had fallen in Arabi, next to the Lower 9th Ward.
For many in New Orleans, Isaac's chief offense was its glacial pace, 6 mph.
"Unfortunately, the storm just won't seem to leave us," Mayor Mitch Landrieu said.
The storm is also noteworthy for its 350-mile girth. Tropical-force winds extended 175 miles from the storm center.
Louisiana officials warned residents not to relax, because Isaac's effects could last into Friday. "Now is not the time to let your guard down," Landrieu said.
"There is much more coming," Jindal said.
By late Wednesday, one-third of Louisiana households — roughly 660,000 homes — were without power, including 160,000 in Orleans Parish, according to spokesperson Chanel Lagarde of New Orleans-based Entergy. Thousands were also without power in Mississippi.
"We haven't been able to get crews out today because of the weather; it continues to be bad here," Lagarde said. "We're hoping to get scouts out in the field in the morning to do damage assessments."
Louis Armstrong New Orleans International Airport had no power. All of its commercial flights were canceled for Thursday, the third straight day, officials said.
A dusk-to-dawn curfew was imposed in New Orleans, where police and the National Guard patrolled the streets.
In Plaquemines, water reached rooftops as police and volunteers in small boats plucked stranded residents from the tops of their homes. Animals were rescued as well, including about 15 dogs, a cat in a cage and even a fawn.
Between nine and 40 people could still be stranded there, Jindal said. Officials planned to send out teams Thursday to decide when and where to breach the levee to relieve the pressure.
"If that's a Category 1 storm, I don't want to go through anything stronger," parish president Billy Nungesser told WWL-TV.
In Mississippi, where residents in three Gulf Coast counties generally obeyed mandatory evacuation orders, roads were flooded and blocked by fallen trees, and all-night curfews were in effect.
"The storm has decided to sit, pretty much unmoved — it's just pushing up water to our tributaries and low-lying areas," said Monica Cooper, spokeswoman for Jackson County, Miss., which includes Pascagoula. "We are preparing for a night of continued rain and flooding."
Susman and Teague reported from New Orleans and Zucchino from North Carolina. Molly Hennessy-Fiske in Los Angeles contributed to this report.