NO might be drained within a week

Col. Duane Gapinski, commander of the Unwatering Task Force for the Corps of Engineers says: "It's a winnable battle... We had the city under control before Rita, and I'm pretty optimistic we're going to do it again."
On Sunday, he said that Plaquemines Parish would take another three weeks.

Hurricane Rita flooded the lower 9th Ward on Friday when water cascaded over four sections of the Industrial Canal...
"I believe that water was pushed from the Intracoastal Waterway into the Industrial Canal by Rita," Gapinski said.
...Water has stopped from flowing over three sections of the Industrial Canal levee. "There is still one section where water is seeping into the 9th Ward," Gapinski said. "As it turns out, there was a breach in that section of the levee. The water is down to seepage and by today we should have that under control."
On Saturday, the Corps of Engineers maintained that repairs it made on levees had remained intact and there were no new breaches when Hurricane Rita struck.
As Gapinski spoke, four helicopters lined up behind him over the Lake Pontchartrain shoreline, waiting to drop 7,000-pound sandbags hooked to cables beneath the aircraft. The sandbags were taken to the breach on the east side of the Industrial Canal just north of the Claiborne Street Bridge. The helicopters dropped 200 sandbags in the breach Saturday. Gapinski said another 200 were to have been dropped Sunday...

The bolded section above might be a bit controversial. There appears to be a question of whether the repairs did indeed hold or not.