Crews will soon begin laying the foundations for the massive pumping stations that will drain New Orleans’ three major outfall canals into Lake Pontchartrain, officials with the U.S. Army Corps of Engineers said Wednesday, adding that the project is on schedule.
The $615 million project is the last major element of $14.5 billion in upgrades the Corps has made to the hurricane risk reduction system in the New Orleans area since Hurricane Katrina. Altogether, the pumps on the 17th Street, Orleans Avenue and London Avenue canals will be able to move more water than any other element of the system.
“It’s on track to be completed and turned over to the local sponsor by the 2017 hurricane season,” said Lt. Col. Austin Appleton, deputy commander of the Corps’ New Orleans District.
Officially known as the Permanent Canal Closures and Pumps project, the work, which began last year, is designed to reduce the risk of flooding from a hurricane that has a 1 percent chance of hitting the area each year. The stations will be able to pump about 24,300 cubic feet per second, enough water to fill the Mercedes-Benz Superdome in less than 90 minutes and enough to prevent water from building up in the canals to the point where it tops or damages the floodwalls.
Work on the foundation of those stations will begin soon, after sand is pushed into the canals to allow equipment to be moved in. Crews will then build cofferdams, barriers that allow water to be pumped out of sections of the canal so work can proceed on the floor of the waterway, and begin work on the structures.
The interim pumps, which have been used in the canals since 2006, will still be able to operate as normal because of gated bypasses that were finished and opened at the end of July, Senior Project Manager Dan Bradley said.
In the event of a storm during construction, equipment would be removed from the site, but the open bypasses would allow the existing pumps to be used to drain the canals, Bradley said.
Once the stations are complete, the bypasses will be integrated into the pumping complex and closed during storms to prevent a surge from flowing back into the canals, he said.
Building the stations will entail digging 51 feet below sea level, lower than crews have had to dig for any other pumping station in the area. That depth was necessary because the stations are required to be able to operate within the existing system, in which Sewerage & Water Board pumping stations push water through the canals to the lake, or in an alternative configuration that would allow gravity to drain the water to the pump stations.
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