|Woman drags suitcase past submerged welcome sign in downtown New Orleans. (Photo courtesy of Reuters/Rick Wilking)|
As levels in Lake Pontchartrain drop slowly, the U.S. Army Corps of Engineers and private contractors are moving to close three lakefront drainage canals to stop the flow of water into New Orleans through breaches in the levee system.
Elsewhere they are punching holes in levees, so that floodwaters trapped behind the floodwall system can drain. At the same time, repair crews are trying to plug gaps that hurricane Katrina punched in two of the canals, so that the New Orleans Sewerage and Water Board can restart its system of 21 pumping stations to speed the draining of the water inside the city's flood protection system.
"We have contractors with heavy equipment, moving stone and gravel to clear debris and cut roads alongside the canal walls, so we can get access to the mouths of the canal, where they spill into the lake," said Al Naomi, the corps' project manager of hurricane protection.
Local contractor Boh Bros. will drive 50-ft sheet piles to close the openings at the 17 St. and London Ave., Naomi said on the morning of Sept. 1. The Orleans St. canal may be closed as well. The canals are trapezoidal, 140-ft across at the top and 40-ft at the base. The channel is 18-ft deep, he added. Inspection crews are also evaluating integrity of the remaining floodwalls.
At the same time, crews have begun to punch holes in the levees in East New Orleans and Chalmette, in St. Bernard's parish. Those areas are lower, Naomi explained, and the holes will help accelerate the drainage, which Corps and city officials say may take 30 days or longer. While contractors are deliberately breaching portions of the system on the hard-hit, low-lying eastern and southern sides of the city, others continue to try to plug breaches in the 17th Ave. and Industrial canals to the north near Lake Pontchartrain. The effort involves dumping super-sized sandbags and concrete jersey barriers from helicopters. Another approach is under consideration as well: sinking concrete-filled barges in the gaps, which are as much as 500-ft across.
The Corps and the New Orleans Sewerage and Water Board are also sending teams to assess the pumping stations, which were taken offline as the storm hit. Once the floodwalls were overtopped and breached, much more water was coming in than the system could pump out, explained John Hall, Corps spokesman. The system can move about 25,000 cubic feet per second, the volume expected from an inch of rainfall in an hour. But once the 17th Ave. and Industrial Canal walls failed, much more water was coming, possibly 1 million cfs or more, said Hall.
Access is more of a problem than contractors and equipment, says Naomi. "I'm told that Interstate 95 from Hammond (La.) is one big parking lot of heavy equipment, waiting to go to work. We're sorting that out right now."
Despite widespread accounts of looting and civil disorder, Naomi said the drainage situation is improving, if only incrementally. "The lake level is dropping, reaching equilibrium with the water behind the flood walls. It will go faster if we can close the canal mouths, patch the breaches and punch holes where it will speed drainage. It's already dry near the airport, in Jefferson Parish. We have a long way to go, but we're making progress."
The situation in Mississippi was also showing slight improvement, according to Gov. Haley Barbour (R). Many of the survivors in the devastated Gulfport-Biloxi area are complaining about the absence of assistance. "When you have total devastation along 50 miles of the Gulf Coast, you are overwhelmed," Barbour said in a television interview. But, he noted, repair crews restored power to some of the petroleum pipelines on Aug. 31. The pipelines are a key infrastructure component, crucial in restoring electricity, telecommunications and other lifelines, Barbour said. "We had some people get electricity back yesterday and the night before," he said. Still, power outages in Mississippi and Alabama are widespread and utility officials say it will be weeks, maybe longer, before the grid is functioning again.