By Verity Murphy
BBC News, New Orleans
Even now, one month after Hurricane Katrina hit, water is still flowing through the breach in New Orleans' 17th Street Canal levee despite the pile of three-ton sandbags used to plug the gap.
When the walls of the 17th Street Canal failed, the water slammed into the streets below
Admittedly the water has slowed to the trickle of a small stream, not the powerful torrent that ripped down houses and swept away cars in a swathe of destruction running for hundreds of metres.
But it is indicative of the huge challenge facing the US Army Corps of Engineers, the group tasked with fixing New Orleans levees and getting the city dry once more.
Nonetheless Mitch Frazier, New Orleans spokesman for the Corps, says their efforts are paying off.
"Things are going well, very well when you consider the difficult circumstances we are working in," he said.
"The city is now 90-95% dry. We do still have some water in the lower Ninth Ward and some in East New Orleans, but the pumps are working on that right now and we expect to be all done by tomorrow."
New Orleans famously sits below sea level, protected by a system of levees and canals designed to withstand a storm of up to Category Three strength.
When Hurricane Katrina swept into town pushing winds of almost Category Five speed hardly anyone there was surprised to see the levee system fail.
Massive breaches on the 17th Street Canal, The London Avenue Canal and the wide, navigable Industrial Canal left 80% of the city flooded.
Plugging the gaps has provided some interim protection
To staunch the water helicopters dropped huge sandbags into the gaps, before metal barges laden with yet more sandbags moved in.
Once the tide had been halted the city's pumping stations, along with mobile ones brought in by the Corps, worked round the clock to shift the water from the streets to Lake Pontchartrain.
Rita set back
After three weeks they had succeeded in drying out 90% of the city, but then Hurricane Rita arrived, pushing more heavy rain.
Knowing the patched up levees were already weak, the Corps' engineers sealed up the mouths of the 17th Street and London Avenue canals with metal sheets.
But with the Industrial Canal this simply was not an option: "The Industrial Canal is just too big, too deep and too wide," Mr Frazier said.
The breaches in the levees are an object of curiosity for local residents
The result was a second, catastrophic breach which flooded the low-lying Ninth Ward again.
But Mr Frazier insists that despite this setback the reconstruction effort is still on schedule.
"Rita did delay us, especially with all of the heavy rain it dumped, but by no more than three or four days," Mr Frazier said.
June 2006 deadline
At present the Corps' engineers say that they have patched up the levees sufficiently to withstand the majority of storms that could come before the hurricane season closes at the end of October.
"The levee heights vary across the city, but in the 17th Street Canal for example we currently have around 10 feet of protection and its getting better and better every day. The pre-Katrina level for that area was 14 or 15 feet," Mr Frazier said.
Fully protecting a city that sits below sea level will be a major challenge
Just as importantly, the engineers say they are on course for getting all of the levees back to pre-Katrina strength by the target date of 1 June 2006.
"Obviously it is a gargantuan mission, but I think we are up for it," Mr Frazier said.
The Corps already has 3,200 personnel repairing hurricane damage across Louisiana and Mississippi, 70 of whom are in New Orleans itself working in partnership with local levee boards and contractors.
Within a week they will be joined by Corps engineers from St Louis, forming the Task Force Guardian team to begin implementing the phased plan for restoring the city's storm safeguards.
But even if the levees are repaired to what they were before, many residents complain that this will still not be good enough - they want to see the levees raised to a level where they can resist a hurricane of Katrina's force.
Mr Frazier says his team are up to the job, but that is not where the problem lies.
"The Corps only has the authority from Congress to fix up the levees to their pre-Katrina level, so that is what we are doing," he explained. "We will need congressional approval and funding to do any more."