NEW ORLEANS Isaac pulled away from the Louisiana coast Thursday morning, leaving New Orleans largely unscathed but still spinning off deadly scenarios in surrounded parishes.
Seven years after Hurricane Katrina leveled the city when man-made levees failed, Hurricane Isaac's power was held at bay by the $14.5 billion fortified federal levee protection system.
But an automatic control panel at a pumping station failed, causing Corps of Engineers crew to manually start two pumps at the 17th Street canal, where one of the levees failed during Katrina. The Corps stressed that the pumps worked as planned, passing the system's biggest test.
'Oft-maligned pumps performed admirably throughout a serious rain event,' said Ken Holder, spokesman for the Corps of Engineers, New Orleans District. 'When something doesn't work, it is inspected manually and the process begins to get it functioning. That's what happened here.'
President Barack Obama declared federal emergencies in 35 Louisiana parishes late Wednesday, a number Gov. Bobby Jindal said he hopes increases to all 64 in the state.
A tropical storm warning remained from Morgan City, La., to the Alabama-Mississippi border, including Lake Pontchartrain and Lake Maurepas more than 41 hours after Isaac first made landfall in Plaquemines Parish early Tuesday night.
While Isaac spared New Orleans, it continued hammering surrounding parishes and Mississippi.
A dam holding back the lake at Percy Quin State Park outside of McComb, Miss., was given a '50-50 chance' of breaking, prompting a mandatory evacuation of points in Tangipahoa Parish along the Tangipahoa River from Kentwood, La. to Robert, La.
If the dam were to fail, the Tangipahoa River would reach 211/2 feet, its highest recording ever at Osyka, Miss., while in Robert, the river would reach 191/2 feet, nearing the height reached in the 1983 flood.
The evacuation in the north part of the parish was only the latest thing officials there had to deal with thanks to Isaac. Evacuations were ongoing Thursday morning for southern portions near Lee's Landing as tidal surge continued to push north. Middendorf's, a famous catfish restaurant in Manchac, took on nearly 5 feet of water.
And officials weren't sure how much damage they were going to find.
'The areas south of Hammond, we really don't know yet,' Tangipahoa Parish President Gordon Burgess said.
Meanwhile, river flooding will remain a concern on the Northshore for the next four days. The Bogue Falaya is expected to crest at Boston Street nine feet above flood stage while the Tchefuncte is set to crest 51/2 feet above its flood stage Thursday night. And the Bogue Chitto could end nearly 10 feet above its flood stage on Saturday.
Rain levels were staggering in places, with Arabi inundated with 25 inches of rain by midmorning Thursday while Hammond received 16.82 inches and New Orleans had 11.06 inches.
Focus shifted Thursday morning to Slidell, where water from bayous was backfilling into the city, including Old Town and much of the southern parts of the city.
A reverse 911 call alerted residents of the flooding throughout the predawn hours, a move St. Tammany Parish President Pat Brister said was made to give people time to get out before water from the overflowing canal reached them.
But officials expressed that they didn't believe the water would get high enough to force roof rescues, a scene that played out throughout the day Wednesday in Plaquemines Parish.
'We're not panicking by any means,' Brister said. 'We absolutely feel that it is under control. We have plenty of resources out there.'
Meanwhile, in LaPlace, a community nearly 30 miles west of New Orleans, officials re-started search-and-rescue efforts as the sun rose for residents as nearly 7-8 feet of water remained in more than 15 areas of the St. John the Baptist Parish town.
Wednesday afternoon, boats and high-water vehicles were put to use rescuing people from areas that haven't flooded in the past from passing tropical systems.
'Clearly there was not an expectation for any of these neighborhoods to flood,' said Natalie Robottom, St. John Parish president. 'There is something wrong with this picture. This has never happened. Water flowed over I-10.'
So far, 3,300 St. John Parish residents had been evacuated. Ninety-five percent of St. John Parish remained without power and officials already had shut water off to Laplace for fear of contamination of the system from Lake Pontchartrain.
In Plaquemines Parish, officials were set to purposely cut a hole in a non-federal levee that was overtopped by storm surge when Isaac made landfall. The flooding trapped more than 125 people in Braithwaite, some of them rescued from their roofs by boat.
Overtopping of a non-federal levee guarding the parish from Barataria Bay allowed water to completely cover Hwy. 23, making it accessible only by boat. The water pushed cattle onto front porches.
But there was some good news a combination of a levee and HESCO baskets held back surge in Jesuit Bend, a small community on the west bank of the Mississippi River in Plaquemines .