World's largest drainage pumping station roars to life on West Bank
Published: Friday, June 03, 2011, 8:00 PM Updated: Friday, June 03, 2011, 9:06 PM
|photo by Chris Granger, Times-Picayune|
Belching thick black smoke from a 5,400-horsepower diesel engine, one of the 11 pumps at the world’s largest drainage pumping station south of Harvey roared to life, sending a torrent of brown water cascading into the Intracoastal Waterway.
The pumping station is part of the fast-track $1 billion West Closure Complex, which includes a 225-foot sector gate to block storm surge from rushing up the Harvey and Algiers canals and threatening thousands of structures in a 70-square-mile area.
“If you had been here 20 months ago, you would have seen nothing but pine trees as far as the eye can see. So there’s obviously been some great progress,” Col. Edward Fleming said during a news conference at the 50-plus-acre complex near the confluence of the two canals.
Eight of the 11 70-ton flower-pot pumps are operational and were tested two at a time Friday, unleashing a powerful waterfall that sent a frothy spray 15 feet into the air.
The pumps, which have 11-foot-diameter blades, cycled on and off like clockwork Friday, and the black exhaust quickly dissipated as the engines warmed up. But things didn’t go nearly as smoothly the first time the pumps were tested several weeks ago.
A bearing on one of the pumps overheated and cracked, prompting the contractor to remove all of the pumps and modify the bearings, said Kevin Wagner, a corps senior project manager who said the need for adjustments was not surprising.
“These are custom pumps,” he said. “It’s not like we can put them in a lab and test them. They had to be adjusted in the field.”
The corps also showed off the 225-foot sector gate, which is the nation’s largest. A tugboat pulled the two pie-shaped gates closed, a 15-minute job that will eventually be done by motors that aren’t finished.
The complex is 83 percent complete and is not expected to be finished until December 2012. But corps officials said it is far enough along to have met their goal of providing protection from a 100-year storm before the hurricane season started Wednesday.
Wagner said the remaining three pumps are expected to be operational by the peak of the hurricane season.
Corps officials ticked off a list of “gee-whiz facts” to convey the size of the project.
With a capacity of 19,140 cubic feet per second, the pump station could fill an Olympic-sized swimming pool in less than five seconds. About 18 million pounds of rebar were used, enough metal to build 30 747 jumbo jets. And the 770,000 cubic yards of clay used would fill the Empire State Building, a somewhat curious yardstick that may have been chosen because the clay would fill just 17 percent of the Superdome, the traditional benchmark for such volume comparisons in southeastern Louisiana.
But perhaps the most important statistic about the sprawling complex is that it will turn 26 miles of levees and floodwalls lining the Harvey and Algiers canals into a second line of defense, greatly reducing the flood risk across a vast swath of the West Bank.
“We’ve taken the perimeter defense out of people’s back yards,” Fleming said.
When the floodgate is closed, the canals will serve as reservoirs for rainwater runoff from a 70-square-mile area, including all or parts of Algiers, Gretna, Terrytown, Harvey, Marrero and Belle Chasse.
To ensure that the canals’ floodwalls aren’t overtopped, the massive pump station must match the output of nine smaller stations that discharge rainwater into the canals.
Fleming said several time-saving factors -- including expedited post-Hurricane Katrina environmental reviews, pre-financing from Congress and involving the contractor in the design stage -- are helping the corps complete what might normally have been a 20-year project in about five years.
He praised the contractor, Gulf Intracoastal Constructors, a joint venture of Kiewit Corp. and Traylor Bros. Inc., for keeping up with an aggressive schedule without compromising safety.
He said workers have logged 1.9 million hours with just one injury that resulted in lost time. A dump truck driver missed a day after his truck overturned while hauling debris when the site was cleared.
A quick tour of the cavernous 500-foot-long pumping station revealed that each pump is powered by a separate 12-cylinder diesel engine that is bigger than a cargo van.
Digital controls and computer screens line the walls, and workers were installing remote controls for the pumps in a safe house inside the thick-walled concrete pump station.
“If you had to ride out a storm, this is probably one of the best places to do it,” Wagner said. “It’s like a concrete bunker inside a concrete bunker.”
The corps may have stolen some of its own thunder for Friday’s pump demonstration when it opened the Bonnet Carre and Morganza spillways last month to divert water from the swollen Mississippi River. Those diversions gushed up to 300,000 cubic feet of water per second, more than 15 times the pump station’s capacity.
Wagner, who is overseeing the pump station project, said Fleming chided him about the flow-rate comparison.
“I was like, ‘Hey, c’mon man, show me some respect,’” Wagner said. “This is still pretty impressive.”
© 2011 NOLA.com. All rights reserved.