The U.S. Army Corps of Engineers has run out of slings used to drop sandbags from helicopters into the breach in a canal levee that is flooding New Orleans, says a spokesman for the Louisiana Dept. of Transportation and Development, which is assisting in the work.
The teams have airlifted in 200 Jersey barriers and 3,000-lb sandbags to dam the breach, says the spokesman, Mark Lambert.
It's a logistical nightmare, Lambert says. The slings must go with the sandbags, so teams are waiting for 250 more slings to arrive. Eventually, barges will be sunk into the lake perpendicular to the levee, with the hope that they will reverse the water's flow back into the lake.
The Corps of Engineers said Wednesday that the water levels in Lake Pontchartrain and inside the city had stabilized and that waters had begun to drop at the rate of half and inch an hour. The water may rise slightly at high tide in the evening, but barring more rainfall, floodwaters should recede, said Maj. Gen. Don Reily, head of the Corps' recovery operation. This should assist efforts of the Corps and the New Orleans sewerage and Water Board's efforts to plug the breach in the 17th St. Canal, which inflow water force expanded to 500 ft across by Aug. 31.
The Corps and the board are trying to drop sand bags and concrete jersey barriers into the gap, then drive sheet piles to stabilize the structure. If those operations are successful, then the city could start pumping equipment at Station No. 6, which can push 10,000 cu ft per sec of water from the canal back into the lake. Officials estimate that it will take 30 days to pump the water from the city once the levee breaches are closed.
Meanwhile, LADOTD officials are already planning to repair a key part of the regions road network by using a repair technique from another hurricane.
The agency plans to restore one of the eight-mile twin spans of Interstate 10 across New Orleans' Lake Pontchartrain, battered by Hurricane Katrina, by taking precast segments off its more battered counterpart, says Lambert. That's what the Florida Dept. of Transportation did for I-10 across Escambia Bay just about a year ago after Hurricane Ivan.
Speaking by cell phone Wednesday afternoon, Lambert estimates that 40% of the eight-mile-long twin spans is damaged or gone, and that the bridge's easterly span bore the brunt of the hurricane's impact. An emergency contract will go out at some point, with repairs expected to take 30 to 60 days after that. The LADOTD hopes to use barges, cranes and other equipment that were situated nearby for another bridge repair job. "We just hope the equipment survived," he says.
LADOTD officials have been on the phone with their FDOT counterparts to learn from the latter's experience in emergency repairs to the Escambia Bay Bridge (ENR 9/27/04, p.12). There, the two-mile, twin span bridge had washed out due to water upsurge when Ivan came ashore. Under a $28-million contract, Gilbert Southern Corp., Peachtree, Ga. used barge-mounted cranes to pick 200-ton concrete beams from the two-lane eastbound crossing and "patch" them into spots on the westbound crossing.
There's no set timeframe for repairing the Lake Pontchartrain spans, because right now "there's nowhere to go" on them. Normally the spans carry some 100,000 vehicles daily.
Swamped City Faces Reality as Levees Fail Sept. 5 , 2005 Issue
State Officials Claim Contractor Failed To Brace Girders Sept. 5 , 2005 Issue
Katrina Takes Out Regions Power Supply Sept. 5 , 2005 Issue
Katrina Floods Gulf Coast, Killing 55, Aug 30, 2005
FEMA Head: Katrina Was 'Catastrophic',, Aug 30, 2005
Katrina Slams Gulf Coast , Aug 29, 2005