* Water tops levee in Plaquemines Parish on city outskirts

* New Orleans mayor says levees in city are holding

* Storm moving slowly, torrential rains continue

* Energy companies start damage assessments

By Ellen Wulfhorst and Scott Malone

NEW ORLEANS, Aug 29 (Reuters) - Hurricane Isaac dumped heavy rains on the U.S. Gulf Coast and caused widespread flooding on Wednesday, but elaborate defenses built to protect New Orleans after the 2005 Hurricane Katrina disaster withstood the onslaught, officials said.

The massive cyclone, which weakened to a tropical storm on Wednesday afternoon as it moved slowly into Louisiana, pushed water over a levy on the outskirts of New Orleans and threatened to flood oil refineries and towns in the state and neighboring Mississippi.

But fears of a repeat of the catastrophe of Katrina that swamped large parts of New Orleans exactly seven years ago and killed 1,800 people, did not materialize and there were no immediate reports of injuries or deaths.

Police and National Guard units, many armed with assault rifles, patrolled the virtually empty downtown area of New Orleans, a port city which normally hums with tourists drawn to its jazz bars, Creole cuisine and French colonial architecture. They were deployed to prevent a repeat of 2005's widespread looting.

Authorities reported four arrests for looting on Wednesday. The mayor said he was clamping a dusk-to-dawn curfew on New Orleans nonetheless.

Storm surges climbed up to 12 feet (3.7 meters) and top sustained winds were up to 70 miles per hour (110 km per hour).

Highway 90, a key interstate roadway on Mississippi's Gulf Coast, was washed out by the storm, which triggered widespread power outages and was expected to bring rainfall accumulations totaling as much as 25 inches (64 cm) to some areas.

New Orleans Mayor Mitchell Landrieu told local radio the city's flood defenses, strengthened since 2005 with a $14.5 billion system of walls, floodgates, levees and pumps had done their job.

"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."

Still, as torrential rains continued to hammer the city -- one location reported 17 inches (43 cm) -- Landrieu later cautioned that it was too soon to declare victory.

The storm taxed the city's sewage system, prompting Landrieu to urge residents to "keep the flushing to a minimum."

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

Isaac was wobbling northwestward near six mph (10 kph), a slow pace that increases the threat of rain-induced flooding.

Outside the city, in low-lying Plaquemines Parish, which stretches southeast from New Orleans, emergency officials said floodwaters had flowed over an 8-foot (2.4-metre) high levee between the Braithwaite and White Ditch districts.

Parish President Billy Nungesser said about 2,000 residents had been ordered to evacuate but only about half were confirmed to have left before Isaac made landfall late on Tuesday.

About 118 people were rescued in Plaquemines, including 25 trapped on their roofs or attics as water rose 14 feet (4.3 meters), authorities said.

"This storm has delivered more of a punch than people thought," Nungesser told CNN. "We're not out of the woods yet."

Plaquemines Parish is cut in two lengthwise by the Mississippi River as it flows to the Gulf of Mexico. Much of it lies outside the greater New Orleans levee system, and construction projects to bolster protection are not complete.

Private citizens in their boats led the rescue effort, Nungesser said, referring to boatmen from the Mississippi Delta and bayous popularly known as the "Cajun Navy."

Jesse Shaffer, a 25-year-old Braithwaite resident, told reporters he and his father, 53, personally rescued more than 20 people during several outings in their fishing boat.

Local television showed rescuers in a small boat chopping through the attic window of a house to pull a man and his four dogs to safety in the Braithwaite subdivision, a neighborhood of brick houses that were submerged up to the first floor.

In Belle Chase, in Plaquemines Parish, canals overflowed and threatened to swamp houses by midday on Wednesday, though several residents said they planned to ride the storm out even as forecasts threatened another 10 to 12 hours of rain.

Patty Mattison, 58, was watching floodwater rise in her yard, threatening to swamp her laundry room. "I'm looking at a little water in the back," Mattison said.

Crews were also rescuing residents after a levee breach in Madisonville in St. Tammany Parish, on the north bank of Lake Pontchartrain on the opposite side from New Orleans, a also outside the federally operated flood protection ring.

Rescue crews used boats and jet-skis to rescue up to 100 people in houses and condominiums there, Jindal said.

"This is a slow-moving storm and it is going to cause a tremendous amount of damage," Jindal warned. He said Louisiana could face 18-26 hours of tropical storm-force winds before Isaac leaves the state on Friday

"This is not over, and there is no such thing as just a tropical storm," said Craig Fugate, director of the Federal Emergency Management Agency and U.S. President Barack Obama's top advisor on disaster response. "You have significant weather impacts still to occur to the state."

Official estimated that Lake Pontchartrain had risen nine feet (three meters) since the start of the storm with peak expected at 6 p.m., according to WWL radio.

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.

Before moving to the Gulf Coast, Isaac killed at least 23 people and caused significant flooding and damage in Haiti and the Dominican Republic before skirting the southern tip of Florida on Sunday.

"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 from a Category 1 hurricane," said Rick Knabb, National Hurricane Center director.

"It's human nature to think that if I think back to my experience with some past hurricane, if this one's a lower category, then I'm going to be fine," Knabb said.

More than 700,000 Louisiana customers of Entergy Corp and other local utilities were without power as of midday. Entergy warned that it would be unable to begin restoring power until winds drop below 30 mph (48 kph).

At 5 p.m. EDT (1900 GMT), Isaac was centered about 60 miles (95 km) west of New Orleans, the NHC said.

Oil production in the U.S. Gulf of Mexico nearly ground to a halt as Isaac closed in on Louisiana on Tuesday and ports and coastal refineries curtailed operations.

But on Wednesday, big oil companies including Royal Dutch Shell and Exxon Mobil Corp began making plans to assess or restart operations.

Intense hurricanes such as Katrina -- which took out 4.5 million barrels per day of refining capacity at one point -- have flooded refineries, keeping them closed for extended periods and reducing fuel supplies.

Louisiana usually processes more than 3 million barrels per day of crude into products like gasoline.

Perceptions that the area's oil facilities would not sustain major damage left international benchmark Brent crude little changed in Wednesday afternoon trading at about $112.70 a barrel.

Loading Slideshow...
  • People rescue cows from floodwaters after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • Angela Serpas, Lainy Serpas

    Angela Serpas cries as she sees her flooded home for the first time since Hurricane Isaac pushed a 10-foot storm surge into Braithwaite, La., Saturday, Sept. 1, 2012. At right is her daughter Lainy Serpas, 11. While New Orleans streets were bustling again and workers were returning to offshore oil rigs, thousands of evacuees couldn't return home to flooded low-lying areas of Louisiana and more than 400,000 sweltering electricity customers in the state remained without power. (AP Photo/Gerald Herbert)

  • A tree falls against a home after Hurricane Isaac passed the area in Braithwaite, La., Saturday, Sept. 1, 2012. While New Orleans streets were bustling again and workers were returning to offshore oil rigs, thousands of evacuees couldn't return home to flooded low-lying areas of Louisiana and more than 400,000 sweltering electricity customers in the state remained without power. (AP Photo/Gerald Herbert)

  • US-VOTE-REPUBLICANS-ROMNEY-WEATHER

    Storm-affected residents make their way out of their flooded neighborhood following Hurricane Isaac in Crown Point, off the road to LaFitte, outside of New Orleans, on August 31, 2012 in Louisiana, where Republican White House hopeful Mitt Romney rushed to visit in a bid to burnish his presidential credentials ahead of his November battle with President Barack Obama. Coming off the back of a rousing Republican convention, Romney sought to build momentum by taking his new campaign plane to New Orleans, where rescue crews are clearing up after Hurricane Isaac unleashed a torrential downpour. AFP PHOTO / Frederic J. BROWN (Photo credit should read FREDERIC J. BROWN/AFP/GettyImages)

  • US Gulf Coast Copes With Aftermath Of Hurricane Isaac

    PLAQUEMINES PARISH, LA - AUGUST 31: Cattle are stuck in a mixture of mud debris washed in by Hurricane Isaac's storm surge on August 31, 2012 in Plaquemines Parish, Louisiana. Officials are attempting to conduct a cattle roundup in Plaquemines in an attempt to save around 200 cattle stranded by the storm. (Photo by Mario Tama/Getty Images)

  • US Gulf Coast Copes With Aftermath Of Hurricane Isaac

    BRAITHWAITE, LA - AUGUST 31: Tombs dislodged by a levee breach from Hurricane Isaac's flood waters sit by a roadway amongst debris on August 31, 2012 in Braithwaite, Louisiana. Louisiana residents continue to cope with the aftermath of Hurricane Isaac with ongoing flooding, destroyed property and many still without electricity. (Photo by Mario Tama/Getty Images)

  • Peter Roccaforte

    Peter Roccaforte walks through floodwaters from Hurricane Isaac at his home in Reserve, La., as some of his clothing hangs out to dry Saturday, Sept. 1, 2012. Floodwaters cover many streets and power remains out in some areas. Louisiana's Public Service Commission said more than 443,000 customers remained without electricity around Louisiana on Saturday morning, days after Hurricane Isaac crept across the state. (AP Photo/David J. Phillip)

  • The exits off of I-10 in Slidell, La. are flooded in the aftermath of Isaac on Thursday, Aug. 30, 2012. Isaac hovered over Louisiana for a third day Thursday, shedding more than a foot of additional rain that forced authorities to hurriedly evacuate areas ahead of the storm and rescue hundreds of people who could not escape as the rapidly rising waters swallowed entire neighborhoods. (AP Photo/The Times-Picayune, Michael Democker) MAGS OUT; NO SALES; USA TODAY OUT

  • Hurricane Isaac Hits New Orleans, Gulf Coast

    SLIDELL, LA - AUGUST 30: Residents travel through their neighborhood by jetski during flooding from Hurricane Isaac's storm surge on the north shore of Lake Pontchartrain on August 30, 2012 in Slidell, Louisiana. The large Category 1 hurricane had slowly moved across southeast Louisiana, dumping huge amounts of rain and knocking out power to Louisianans in scattered parts of the state. The weather system has now been downgraded to a tropical storm but is still producing heavy rains and flooding as it moves north. (Photo by Mario Tama/Getty Images)

  • Anthony Segrave rides in his boat as he leaves his son's flooded home in the aftermath of Hurricane Isaac in Slidell, La., Friday, Aug. 31, 2012. Isaac is now a tropical depression and the center was on track to cross Arkansas on Friday and southern Missouri on Friday night, spreading rain as it goes. (AP Photo/David J. Phillip)

  • Homes in LaPlace, La., west of US 51 and south of I-10, are covered in floodwaters in the aftermath of Isaac on Thursday, Aug. 30, 2012. Isaac hovered over Louisiana for a third day Thursday, shedding more than a foot of additional rain that forced authorities to hurriedly evacuate areas ahead of the storm and rescue hundreds of people who could not escape as the rapidly rising waters swallowed entire neighborhoods. (AP Photo/The Times-Picayune, Michael Democker) MAGS OUT; NO SALES; USA TODAY OUT

  • An intentional levy breach that was created to alleviate trapped floodwater is seen in the community of Braithwaite, La., in the aftermath of Hurricane Isaac, Thursday, Aug. 30, 2012. (AP Photo/Gerald Herbert)

  • Tony Rodriguez, right, carries his baby daughter Nicole as they and his wife Jodi Clelland leave their flooded home in the aftermath of Hurricane Isaac in Slidell, La., Friday, Aug. 31, 2012. Isaac is now a tropical depression and the center was on track to cross Arkansas on Friday and southern Missouri on Friday night, spreading rain as it goes. (AP Photo/David J. Phillip)

  • The city of New Orleans lies under a heavy band of storms in the aftermath of Isaac on Thursday, Aug. 30, 2012. Isaac hovered over Louisiana for a third day Thursday, shedding more than a foot of additional rain that forced authorities to hurriedly evacuate areas ahead of the storm and rescue hundreds of people who could not escape as the rapidly rising waters swallowed entire neighborhoods. (AP Photo/The Times-Picayune, Michael Democker) MAGS OUT; NO SALES; USA TODAY OUT

  • Interstate 10 in LaPLace, La. at the approach of the Twelve Mile Bridge is underwater because of Hurricane Isaac Thursday, August 30, 2012. Isaac soaked Louisiana for yet another day and pushed more water into neighborhoods all around the city, flooding homes and forcing last-minute evacuations and rescues. New Orleans itself was spared, thanks in large part to a levee system built after Katrina. (AP Photo/The Times-Picayune, John McCusker) MAGS OUT; NO SALES; USA TODAY OUT

  • This aerial photo shows the pumping station at the 17th Street Canal, built after Hurricane Katrina breached the wall and flooded New Orleans, Thursday, Aug. 30, 2012. Isaac soaked Louisiana for yet another day and pushed more water into neighborhoods all around the city, flooding homes and forcing last-minute evacuations and rescues. New Orleans itself was spared, thanks in large part to a levee system built after Katrina. (AP Photo/Gerald Herbert)

  • A car sits submerged after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • Buster stands behind sand bags as he stares at the flood waters around his home, Thursday, Aug. 30, 2012, in LaPlace, La. Isaac has caused major flooding in the region. (AP Photo/Eric Gay)

  • Lonney Sciortino

    Lonney Sciortino prepares to cut down a tree which fell on top of his tamale stand during Isaac in Arabi, La.,Thursday, Aug. 30, 2012. Isaac's maximum sustained winds had decreased to 45 mph and the National Hurricane Center said it was expected to become a tropical depression by Thursday night. The storm's center was on track to cross Arkansas on Friday and southern Missouri on Friday night, spreading rain as it goes. (AP Photo/David J. Phillip)

  • Homes are surrounded by flooded water after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • A submerged cow is stranded amid debris in floodwaters after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • Isaac Fields, Victor Jones

    Isaac Fields, left, and Victor Jones use street signs to paddle a boat out of their flooded neighbor, Thursday, Aug. 30, 2012, in LaPlace, La. Isaac has caused major flooding in the region. (AP Photo/Eric Gay)

  • The St. Paul Missionary Baptist Church is seen flooded after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • Flooded water surrounds homes after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • Hurricane Isaac Hits New Orleans, Gulf Coast

    SLIDELL, LA - AUGUST 30: A resident evacuates from flooding from Hurricane Isaac's storm surge on the north shore of Lake Ponchartrain on August 30, 2012 in Slidell, Louisiana. The large Category 1 hurricane had slowly moved across southeast Louisiana, dumping huge amounts of rain and knocking out power to Louisianans in scattered parts of the state. The weather system has now been downgraded to a tropical storm but is still producing heavy rains and flooding as it moves north. (Photo by Mario Tama/Getty Images)

  • Hurricane Isaac Hits New Orleans, Gulf Coast

    LAPLACE, LA - AUGUST 30: A man heads to check on his house through flood water that came on shore from Lake Pontratrain during Hurricane Isaac near the Indigo Lakes subdivsion on August 30, 2012 in LaPlace, Louisiana.The large Category 1 hurricane had slowly moved across southeast Louisiana, dumping huge amounts of rain and knocking out power to Louisianans in scattered parts of the state. The weather system has now been downgraded to a tropical storm but is still producing heavy rains and flooding as it moves north. (Photo by Chris Graythen/Getty Images)

  • Chuck Cropp, center, his son Piers, left, and wife Liz, right, wade through floodwaters from Hurricane Isaac Wednesday, Aug. 29, 2012, in New Orleans. As Isaac made landfall, it was expected to dump as much as 20 inches of rain in several parts of Louisiana. (AP Photo/David J. Phillip)

  • Homes are flooded as Hurricane Isaac hits Wednesday, Aug. 29, 2012, in Braithwaite, La. As Isaac made landfall, it was expected to dump as much as 20 inches of rain in several parts of Louisiana. (AP Photo/David J. Phillip)

  • Kneaka Griffin, Ra-Maaz Williams

    Kneaka Griffin, of Davant, La., holds Ra-Maaz Williams, 5 months, at an evacuation shelter after Isaac made landfall as a hurricane, in Belle Chasse, La., Wednesday, Aug. 29, 2012. (AP Photo/Gerald Herbert)

  • Law enforcement officers and first responders help a family to reach dry land after they were rescued from floodwaters caused by Isaac in Pearlington, Miss., Wednesday, Aug. 29, 2012, during a nonstop rain. A number of residents of the small community were trapped by the rising waters and had be rescued or waited until the low tide when waters receded so they could walk out. (AP Photo/Rogelio V. Solis)

  • The waters of the Mississippi Sound surround a traffic sign along Coden Belt Road, Wednesday, Aug. 29, 2012 in Coden, Ala. as Isaac makes landfall along the Gulf Coast. Isaac, downgraded to a tropical storm, has top sustained winds of 70 mph (112 kph), just below the hurricane threshold of 74 mph (119 kph). The storm is about 50 miles (80 kilometers) west-southwest of New Orleans, where it is bringing drenching rains and fierce winds. (AP Photo/Mobile Register, G.M. Andrews MAGS OUT

  • Hurricane Isaac Hits New Orleans, Gulf Coast

    NEW ORLEANS, LA - AUGUST 29: A downed streetlight lies in the rain from Hurricane Isaac in the Central Business District on August 29, 2012 in New Orleans, Louisiana. The large Level 1 hurricane is slowly moving across southeast Louisiana, dumping large amounts of rain and knocking out power to Louisianans in scattered parts of the state. (Photo by Mario Tama/Getty Images)

  • Lights are reflected on Canal Street as a police officer patrolling the area passes a pedestrian as storm bands from Hurricane Isaac hit, Tuesday, Aug. 28, 2012, in New Orleans, Louisiana. Isaac, a massive storm spanning nearly 200 miles from its center, made landfall Tuesday evening near the mouth of the Mississippi River. (AP Photo/Eric Gay)

  • David Stefano

    Bay St. Louis, Miss., fireman David Stefano reacts as he and other first responders use an airboat to reach a house fire Tuesday, Aug. 28, 2012. Isaac's rainfall flooded a number of streets in this Bay St. Louis subdivision, preventing firemen from responding quickly to the fire that destroyed a house. (AP Photo/Holbrook Mohr)

  • Ronnie Willis

    Ronnie Willis makes his way across Canal Street through the wind and rain from Hurricane Isaac Wednesday, Aug. 29, 2012, in New Orleans. (AP Photo/David J. Phillip)

  • Hurricane Isaac Hits New Orleans, Gulf Coast

    NEW ORLEANS, LA - AUGUST 29: Heavy rain from Hurricane Isaac obsures the view of the Crescent City Connection Bridge over the Mississiippi River early on August 29, 2012 in New Orleans, Louisiana. The large Level 1 hurricane slowly moved across southeast Louisiana, dumping huge amounts of rain and knocking out power to Louisianans in scattered parts of the state. (Photo by John Moore/Getty Images)

  • Timbers smolder after a fire gutted a house on stilts in a Bay St. Louis, Miss., neighborhood after rising storm waters from Isaac prevented firemen from responding quickly with their trucks Tuesday, Aug. 28, 2012. First responders used an airboat to reach the house in order to make sure the flames did not affect any neighboring homes. (AP Photo/Holbrook Mohr)

  • Waves tear apart a pier along the Mobile Bay near Dauphin Island on Tuesday, August 28, 2012. Alabama took a glancing blow from Hurricane Isaac on Tuesday as it headed toward landfall in the northwestern Gulf of Mexico, but the storm still threatened the coast with high winds, torrential rain and pounding surf. (AP Photo/Butch Dill)

  • Bay St. Louis, Miss., first responders brave a driving rain storm as they use an airboat to reach a house fire in a flooded subdivision, Tuesday, Aug. 28, 2012. After several attempts to reach the house fire, flooded streets forced the fire fighters to use the airboat. (AP Photo/Holbrook Mohr)

  • A woman stands on a partially submerged picnic bench in the storm surge from Isaac, on Lakeshore Drive along Lake Pontchartrain, as the storm approaches landfall, in New Orleans, Tuesday, Aug. 28, 2012. (AP Photo/Gerald Herbert)

  • Waves tear apart a pier along Mobile Bay near Dauphin Island on Tuesday, August 28, 2012 in Coden, Ala. Alabama took a glancing blow from Hurricane Isaac on Tuesday as it headed toward landfall in the northwestern Gulf of Mexico, but the storm still threatened the coast with high winds, torrential rain and pounding surf. (AP Photo/Butch Dill)

  • First responders seek the assistance of a City of Bay St. Louis, Miss., dump truck to tow their airboat back to their launch site after running aground Tuesday, Aug. 28, 2012. Isaac's rainfall flooded a number of streets in this Bay St. Louis, Miss., neighborhood preventing firemen from using their fire trucks. First responders used an airboat to reach a burning house in order to make sure the flames did not affect any neighboring homes. (AP Photo/Holbrook Mohr)

  • Alex, left, and Adam ,three-month-old Chihuahua puppies, play in their new kennel at the Houston SPCA on Tuesday, Aug. 28, 2012, in Houston. These two were among 70 cats and dogs that were evacuated from St. Bernard Parish Animal Control in anticipation of Hurricane Isaac. (AP Photo/Houston Chronicle, J. Patric Schneider)

  • Debris from crashing waves lies strewn over the parkway going to Dauphin Island forcing a closure to the island on Tuesday, August 28, 2012 in Coden, Ala. Alabama took a glancing blow from Hurricane Isaac on Tuesday as it headed toward landfall in the northwestern Gulf of Mexico, but the storm still threatened the coast with high winds, torrential rain and pounding surf. (AP Photo/Butch Dill)

  • Debris lies strewn over the parkway going to Dauphin Island forcing a closure to the island on Tuesday, August 28, 2012 in Coden, Ala. Alabama took a glancing blow from Hurricane Isaac on Tuesday as it headed toward landfall in the northwestern Gulf of Mexico, but the storm still threatened the coast with high winds, torrential rain and pounding surf. (AP Photo/Butch Dill)

  • Dillard University students stay at the shelter in the gym of Centenary Colleges as they evacuated from New Orleans because of hurricane Isaac Tuesday afternoon, Aug. 28, 2012 in Shreveport, La. (AP Photo/The Times, Henrietta Wildsmith)

  • The Waterfront Seafood company is flooded as water covers Shell Belt Road in Bayou La Batre, Ala. on Tuesday, Aug. 28, 2012. The U.S. National Hurricane Center in Miami said Isaac became a Category 1 hurricane Tuesday with winds of 75 mph. It could get stronger by the time it's expected to reach the swampy coast of southeast Louisiana. (AP Photo/Butch Dill)

  • Teresa Ragas, left, and her husband Bertrand Ragas, of Port Sulphur, La., lie side-by-side in cots at an evacuation shelter in Belle Chasse, La., due to the impending landfall of Isaac, which is expected reach the region as a hurricane this evening, Tuesday, Aug. 28, 2012. The U.S. National Hurricane Center in Miami said Isaac became a Category 1 hurricane Tuesday with winds of 75 mph. (AP Photo/Gerald Herbert)

  • A concerned neighbor checks on a car as a storm surge from Isaac pushes into Panama City, Fla. on Tuesday, Aug. 28, 2012. (AP Photo/The News Herald/Panama City, Fla., Andrew Wardlow) MANDATORY CREDIT

  • Senior hurricane specialist Stacy Stewart updates Isaac to a category one hurricane at the National Hurricane Center in Miami, Tuesday, Aug. 28, 2012. Forecasters at the National Hurricane Center warned that Isaac, especially if it strikes at high tide, could cause storm surges of up to 12 feet (3.6 meters) along the coasts of southeast Louisiana and Mississippi and up to 6 feet (1.8 meters) as far away as the Florida Panhandle. (AP Photo/Alan Diaz)

  • Michelle Hice, Tommy Leonard

    Animal control officer Michelle Hice puts a temporary identification collar on "Snuggles,' as evacuee Tommy Leonard hands him over for safe keeping, at an evacuation shelter in Belle Chasse, La., due to the impending landfall of Isaac, which is expected reach the region as a hurricane this evening, Tuesday, Aug. 28, 2012. The U.S. National Hurricane Center in Miami said Isaac became a Category 1 hurricane Tuesday with winds of 75 mph. (AP Photo/Gerald Herbert)



live blog

Oldest Newest

According to BBC News, the U.S. Geological Survey found that "The storm surge ahead of Hurricane Isaac made the Mississippi River run backwards for 24 hours."

Read the full story here.

Share this:

National Hurricane Center issued the following advisory at 4 p.m. CDT:

...TROPICAL DEPRESSION ISAAC BRINGING HEAVY RAINFALL AND THE THREAT OF FLASH FLOODING TO THE MIDDLE MISSISSIPPI RIVER VALLEY...

More here.

Share this:

Share this:
@ The_Gambit : The city just announced a water boil advisory for Venetian Isles, in effect until further notice.

Share this:
@ jimwxgator : More MAJOR flooding from Isaac today in Pine Bluff, AR. via @KATV_Weather: http://t.co/9SWtF75p

Share this:
@ NOLAnews : Isaac's floodwaters should start to recede in St. Tammany Parish http://t.co/IvG0v4UY

Share this:
@ NOLAnews : Isaac evacuees database available for St. John Parish families http://t.co/BegMKyc4

Share this:
@ chadmyerscnn : #Isaac is now a trop. depression. Winds to 35mph. Lingering storms coming in from the Gulf may have higher gusts or tornadoes.

Share this:
@ wunderground : Over 1 million people without power in LA/MS due to #Isaac.

Share this:
@ AP : BREAKING: Crews begin breaching levee stressed by Isaac flooding in La.'s hard-hit Plaquemines Parish: http://t.co/Z53F2Omf

Share this:
@ NOLAnews : Controlled release of water from Tangipahoa Lake in Miss. begins http://t.co/Cxrzf6h7

Share this:

Curfew has been lifted in New Orleans.

Share this:
@ twc_hurricane : Tornado warning: southeast Kemper, northeast Lauderdale counties in eastern MS until 2:30pm. Details: http://t.co/yaxQlZkQ #Isaac

Share this:

Share this:
@ NOLAnews : Plaquemines sheriff swept away, saved in dramatic Hurricane #Isaac rescue - http://t.co/7dzVpP51

Share this:

Share this:
@ twc_hurricane : Flash flood warning: St Charles & St John The Baptist parishes in Louisiana until 4:15pm CDT. Details: http://t.co/4wheT4cj

Share this:
@ NOLAnews : Miss. officials to breach Isaac-damaged dam on Tangipahoa River - http://t.co/uG8ir7xK

Share this:
@ twc_hurricane : Tropical Storm Isaac: 1 PM CT, 40 mph winds, 992 mb, moving NNW at 9 mph. http://t.co/yJDeDChu

Share this:
@ Jmoon901 : RT @NOLAnews: LSU officials decide to reopen Baton Rouge campus for classes on Friday http://t.co/OR01ZGlv

Share this:

From Tangipahoa.org:

MISSISSIPPI EMERGENCY MANAGEMENT HAS NOTIFIED GOHSEP AND TANGIPAHOA PARISH GOVERNMENT THAT THE DAM AT LAKE TANGIPAHOA AT PERCY QUINN STATE PARK IS DAMAGED BUT HAS NOT FAILED. OUT OF CAUTION, TANGIPAHOA PARISH PRESIDENT GORDON BURGESS CONTINUES TO CALL FOR A MANDATORY EVACUATION OF ALL AREAS ALONG THE TANGIPAHOA RIVER.

Shelter locations are as follows: Hammond West Side Elementary Montessori School, Hammond Junior High Magnet School, Natalbany Elementary School, Nesom Middle School, Amite High School, and Kentwood High Magnet School.

GOVERNOR BOBBY JINDAL AND PARISH PRESIDENT GORDON BURGESS HAVE CALLED A 2PM PRESS CONFERENCE TO BE HELD AT THE TANGIPAHOA PARISH COUNCIL CHAMBERS AT 206 EAST MULBERRY ST IN AMTE, LOUISIANA.

Click here for more information.

Share this:

From Tangipahoa.org:

MISSISSIPPI EMERGENCY MANAGEMENT HAS NOTIFIED GOHSEP AND TANGIPAHOA PARISH GOVERNMENT THAT THE DAM AT LAKE TANGIPAHOA AT PERCY QUINN STATE PARK IS FAILING. TANGIPAHOA PARISH PRESIDENT GORDON BURGESS IS CALLING FOR A MANDATORY EVACUATION OF ALL AREAS ALONG THE TANGIPAHOA RIVER.

Shelter locations are as follows: Hammond West Side Elementary Montessori School, Hammond Junior High Magnet School, Natalbany Elementary School, Nesom Middle School, Amite High School, and Kentwood High Magnet School.

Click here for more information.

Share this:
@ MikePerlstein : Landrieu: NOLA has largest police presence on the street since Katrina: 2,900 cops, troopers and Nat'l Guard troops.

Share this:
@ twc_hurricane : Tornado warning: northeastern Choctaw County in southwest Alabama until 12:45pm CDT. Details: http://t.co/rgwzMMXX #Isaac

Share this:
@ twc_hurricane : Flash flood warning: Mobile and Washington counties in AL until 5:45pm CDT. This includes the city of Mobile. #Isaac

Share this:

"But levees alone won't protect our people."

Share this:
@ The_Gambit : Jindal: Tangipahoa levee has not been breached, despite earlier reports. If breached, 90 minutes to flooding in Kentwood, La.

Share this:

Jindal: "Every storm is different. Just because your house didn't flood last time doesn't mean it won't flood this time."

Share this:

Jindal: Up to 60,000 in evacuation zone

Share this:
@ WAFB : Here is a pic of the dam in Pike County, MS. http://t.co/BNO8mQHB http://t.co/FEZaDAMl

Share this: