The world's biggest drainage pumping station, sector gate will help block storm surge
Marking a milestone in construction of the world's biggest drainage pumping station Friday, four large hoses draped over a cofferdam began re-watering the area around the massive concrete structure south of Harvey.
But the sheer size of the $1 billion project made the occasion a bit anti-climactic. It took five days to flood the 50-plus-acre site with 18 feet of water.
"It's like when the swimming pool was finally finished at my house, and the kids were all excited to jump in right away," said Kevin Wagner, an Army Corps of Engineers senior project manager. "Then we put the garden hose in, and they had to wait two days for it to fill up."
This portion of the project wrapped up Tuesday after a contractor cut into a levee adjacent to the cofferdam Monday to allow water from the Gulf Intracoastal Waterway to flow freely into the area around the 11-bay pump station, which has a footprint equal to two football fields.
"We wanted to take it slow at first to make sure there is no erosion from rushing water," Wagner said.
The pump station and a 225-foot sector gate to be installed in April are part of the West Closure Complex to block storm surge from entering the Harvey and Algiers canals, the centerpiece of the corps' efforts to upgrade 66 miles of West Bank levees and floodwalls.
To prevent interior flooding from rain when the gate is closed, the new pumping station must match the output of nine smaller pumping stations that discharge rainwater runoff into the two canals, which drain all or parts of Algiers, Gretna, Terrytown, Harvey, Marrero and Belle Chasse.
With a capacity of 19,140 cubic feet, or 143,000 gallons, of water per second, the station could fill an Olympic-size pool in less than five seconds.
Construction began less than 18 months ago, and the project is 61 percent complete. Although the complex isn't expected to be completed until the end of 2012, Wagner said it will be far enough along by June to meet the corps' goal of providing protection from a 100-year storm.
Wagner praised the contractor, Gulf Intracoastal Constructors, a joint venture of Kiewit Corp. and Traylor Bros. Inc., for keeping the sprawling project on schedule without compromising safety.
He said workers have logged 1.4 million hours with just one relatively minor accident that resulted in lost time.
"That's a very significant achievement given how fast we're moving and how many moving parts there are on this project," Wagner said.
A quick tour of the cavernous pumping station showed that all but one of the 11, 11-foot-diameter flower-pot pumps have been installed. Each pump will be powered by a 12-cylinder, 5,400-horsepower diesel engine that is bigger than a cargo van.
This week, the corps plans to release a time-lapse photo sequence of the five-day re-watering process.
But the real drama will unfold in April or May when the contractor begins testing the massive pumps, creating a Niagara Falls-like cascade of water from the 500-foot-wide pumping station.
"You're going to want to bring your bathing suit," joked Col. Edward Fleming, commander of the corps' New Orleans District.
"And a surfboard," Wagner added.
•••••••
Paul Rioux can be reached at prioux@timespicayune.com or 504.826.3785.