Corrosion in parts of New Orleans' hurricane protection system will force the Army Corps of Engineers to install temporary pumps at a key location ahead of the June 1 start of hurricane season, the agency announced Thursday.
The decision comes after the Corps in March publicly detailed heavy corrosion that had turned up in one of the 17 pumps at the city's three main outfall canals, and that lesser damage was found in others.
The corrosion has occurred only five years after construction was complete. The pumps were intended to last 35 years.
Temporary pumps will be installed at the London Avenue Canal station, where the heavy corrosion was found in what is known as Pump #1, the Corps said. The corroded pump at London Avenue is being repaired and is expected to be ready ahead of hurricane season. Corrosion was identified as the cause of its failure in February.
The discovery of corrosion at that pump set off an inspection of the other 16 pumps at the three stations, which also include the 17th Street and Orleans Avenue canals.
"To date, nine of the 16 pumps have been inspected and, after minor repairs, returned to operational status," the Corps said in a statement. "Each of nine inspected pumps exhibited significantly less corrosion than identified on the London Ave. Pump #1."
'All necessary precautions'
It was unclear how many temporary pumps will be installed at London Avenue, but there will be enough to add capacity for 1,000 cubic feet per second of water. Corps spokesman Ricky Boyett said London Avenue was designed to have more capacity than needed, but the agency wants to ensure enough is in place should any pumps there remain down during hurricane season. A total of six pumps are located at London Avenue, four with a capacity of 1,800 cfs and two at 900 cfs.
Kelli Chandler, regional director for the Southeast Louisiana Flood Protection Authority-East, which oversees operation of the three stations, called the extra capacity "a belt-and-suspenders approach as we come to storm season."
"Hopefully, we won't need them," she said of the temporary pumps. "But we are glad that the Corps is taking all the necessary precautions."
Meanwhile, Boyett said the hunt for the cause of the corrosion is ongoing, including analysis by metallurgists. It is not yet clear whether the issues related to the severe corrosion at Pump #1 at London Avenue are different from what has been detected elsewhere, he said.
The design-build contractor, PCCP JV, is involved in the investigation. The joint venture includes Kiewit Louisiana Co., whose parent headquarters is in Omaha, Nebraska; Traylor Bros. Inc., based in Evansville, Indiana; and the M.R. Pittman group, located in St. Rose. The pump manufacturer was Patterson Pump, based in Georgia.
The state will not have to foot the bill for either the short- or long-term repairs, though it is unclear to what degree any of the companies involved may be required to pay.
Once inspections are complete and the cause identified, the Corps and the joint venture "will develop a path forward for long-term repairs to ensure reliable and sustainable pumps that meet the 35-year design specifications," the Corps said. "This subsequent work will occur outside of hurricane season to minimize the risk of reduced pumping capacity during a tropical weather event."
Vital infrastructure
The pumps, separate from those operated by the Sewerage & Water Board, are part of an elaborate, $14.6 billion flood protection system put in place after the levee breaches that inundated the city during Hurricane Katrina in 2005.
They are located in three structures designed to both keep storm surge out of the canals and pump water from within them into Lake Pontchartrain during hurricanes.
Floodwalls along two of the canals – London Avenue and 17th Street – failed in the 2005 storm, contributing immensely to the engineering failures that flooded 80% of New Orleans and killed hundreds of people.
The structures at the end of each canal, built at a cost of $726 million, are known as permanent canal closures and pumps, or PCCPs. When hurricanes arrive, the canals are shut off to block storm surge from rushing into them and prevent breaches.
But because water continues to build up inside the canals while the gates are shut, it must be pumped out into the lake to assure it doesn't rise above 8 feet, the level the Corps has determined would threaten floodwalls.
Editor's note: This story was updated on April 27 with further details.