Isaac has weakened to tropical storm status, though the U.S. National Hurricane Center warns that life-threatening hazards stemming from storm surges and inland flooding persist.

The Hurricane Center downgraded Isaac from a Category 1 hurricane to a tropical storm shortly after 2 p.m. CDT Wednesday.

After stalling near Louisiana’s Gulf Coast, Isaac is slowly moving northwest, drenching New Orleans and the Mississippi Gulf Coast with heavy rains. The storm has led to floods and power outages as it batters the region with powerful winds.

Early Wednesday evening, a state official in Louisiana announced that a levee in rural Plaquemines Parish will be breached to relieve pressure as soon as equipment can be brought to the site.

A storm surge was enough to "overtop" a nearly 30-kilometre stretch of levee in the parish, flooding some homes.

Garret Graves, head of the State Coastal Protection and Restoration Authority, said weather conditions will prevent equipment from arriving on Wednesday.

Meanwhile, officials have had to rescue dozens of residents by boat in the area, after they were stranded by floodwaters.

Louisiana Gov. Bobby Jindal said the Louisianna National Guard has deployed 14 high-water vehicles and 10 boats to the parish to assist with the search and rescue efforts of the nearly 3,000 residents remaining in the area.

As of 7 p.m. CDT, the Hurricane Center pegged the storm around 50 kilometres south of Baton Rouge and 95 kilometres west of New Orleans, with maximum sustained winds of 90 km/h.

Forecasters at the Hurricane Center expect the storm to keep on its northwesterly path overnight Wednesday, before turning north-northwest toward Arkansas.


Since Isaac blew ashore as a Category 1 hurricane at 7:45 p.m. Tuesday evening, it has not packed the force that saw Hurricane Katrina devastate the region in 2005, but its slow pace moving inland means the threat of flooding from storm surges and heavy rain remains high.

In a bulletin, the centre warned of a coastal storm surge and inland flood threat expected to last through Wednesday night.

The centre estimates that rising flood water levels could reach up to 3.6 kilometres around Mississippi and southeastern Louisiana, although Alabama and the Florida panhandle may experience flooding as well.

A tropical storm warning is in effect for a region stretching east from Cameron, La. to the Alabama-Florida border.

Earlier hurricane watches and warnings have been discontinued.

Meanwhile an estimated 700,000 people throughout southern Louisiana are believed to be without power, after the storm made landfall bringing a 3-metre wall of water with it.

Jindal warns of ‘slow-moving storm’

Earlier on Wednesday, Jindal warned that Louisiana would continue to face the effects of the storm throughout the coming days.

“Bottom line is this storm is a very slow-moving storm. It will be moving through our state and we’ll be dealing with this storm through early Friday morning,” he said.

Jindal said that 56 parishes have declared a state of emergency, including Plaquemines Parish.

The governor updated the status on several other parishes and said there are unconfirmed reports of one death in the Gretna Parish due to a fire in a commercial building.

Storm batters New Orleans on anniversary of Katrina

Issac’s winds and rains lashed New Orleans on the seventh anniversary of Hurricane Katrina – causing a flood of memories to resurface, said Mayor Mitch Landrieu.

“We all recognize the irony that today is the seventh anniversary of Katrina,” he said. “For those of us who live here this brings back very painful memories. Our lives in this area of the country are defined by before Katrina and after Katrina.”

Landrieu said the devastating 2005 hurricane -- which killed more than1,800 people – changed many things about the city and the city’s residents.

“It has redirected the way we do many things,” he said before his connection was cut out.

Landrieu has ordered a dusk-to-dawn curfew in New Orleans in an effort to prevent the kind of looting that plagued the city after Katrina tore through the region. But police have reported few problems so far.

Katrina, now considered the costliest natural disaster in U.S. history, made landfall as a Category 3 hurricane. Katrina's 220 km/h winds tore through Louisiana and Mississippi, leaving 1,800 dead and countless more lives uprooted.

Many saw Katrina as an engineering disaster, as well as a natural disaster.

Isaac is seen as a test of the New Orleans levee system that has since been repaired and improved at a cost of US$14 billion.

With files from The Associated Press