The last big piece of the multibillion-dollar system built after Hurricane Katrina to protect the New Orleans area from flooding during a hurricane or other severe storm is in place, officials said Thursday, marking the end of construction on a set of enormous pumps that will empty the city's three main drainage canals into Lake Pontchartrain.
The three pumping stations, designed to push water out of the 17th Street, Orleans and London Avenue canals during severe storms, form one of the most state-of-the-art flood protection systems in the world.
Working together, they can move enough water to fill the Mercedes-Benz Superdome in about an hour and a half.
Local, state and federal officials celebrated the end of the project during a ribbon-cutting ceremony Thursday at the 17th Street Canal pumping station, nearly 13 years after the levee failures that caused the city to flood during Katrina.
“The metro area now has the most robust flood defense system it has ever had,” Southeast Louisiana Flood Protection Authority-East President Joe Hassinger said.
“I can assure the public that with the Flood Protection Authority operating these structures, the barriers will be properly manned, the barriers will be properly maintained, and when the water comes they will perform.”
The pumps were formally declared complete earlier in May by the Army Corps of Engineers, which was responsible for building $14.5 billion in flood protection upgrades in the metro area after Katrina.
They've now been turned over to the Flood Protection Authority-East, which is responsible for the rest of the system of floodwalls, levees and gates that protect most parts of the east banks of Orleans, Jefferson and St. Bernard parishes.
That system is designed to handle storms that have a 1 percent chance of occurring each year, but Col. Michael Clancy, the Corps’ district commander and engineer for the New Orleans district, warned that storms could still exceed its capabilities.
“We still live in a high-risk area, and it’s a matter of fact that the full fury of Mother Nature can overwhelm our system, as great as it is — and it’s safe to say we’re the most risk-reduced city, structurally, in the world,” Clancy said. “But we’re still a high-risk city. With the surrounding area, we’re essentially an island in the Gulf of Mexico.”
The Permanent Canal Closures and Pumps, as the project is officially known, are located at the lake end of the canals that normally drain most of the east bank of New Orleans, Old Metairie and Old Jefferson.
They are designed to be used only in storms that cause the water level of Lake Pontchartrain to rise by 4 feet or more, a height that could push water back into the canals and cause their floodwalls to fail, as happened during Katrina.
In such a storm, gates that block off the entrance to the canals would be closed, keeping out water from the lake. The stormwater pumped into the canals by the New Orleans Sewerage & Water Board would then be pushed over the gates by the pump stations, which can move a combined 24,300 cubic feet of water per second.
Temporary pumps and closures on the canals have been performing those functions since shortly after Katrina.
When needed, the pump stations can operate more or less autonomously. When run in what Derek Boese, chief administrative officer of the Flood Protection Authority, termed “storm mode,” the stations will automatically determine the water levels in the canals and make adjustments to the pumps' operation accordingly.
Crews can also control the pumps using computers from within a safe-house inside the station at the mouth of each canal or else manually at the pumps themselves.
All three buildings are designed to withstand the sustained winds of a Category 5 hurricane and 200-mph gusts of wind.
The Corps originally bid out the pumps and gates project in 2013, with PCCP Constructors JV winning the $615 million contract. The price of the project, which was supposed to be completed last year, grew by about $100 million over the years, and Clancy said the total cost — when other, related projects are taken into account — will be about $850 million.
Plans originally called for the Sewerage & Water Board to operate the stations, but the Flood Protection Authority, which operates most of the rest of the hurricane protection system on the east bank, offered to step in after last summer’s flooding revealed serious deficiencies at the city agency.
The S&WB will be responsible for paying half of the estimated $4 million annual cost of operating the stations.
The Flood Protection Authority is still negotiating with Jefferson Parish to determine how much of the operating costs that parish will be responsible for, Boese said.
While the pump stations represent the final link in the protective system that rings the New Orleans area, there is still about $1.3 billion worth of work left to do on other projects funded in the aftermath of Katrina.
Most of that money is going toward "armoring" of levees to reduce the risk that they will fail if water overtops them, drainage improvements that are part of the Southeast Louisiana Urban Flood Control Project and levee improvements along the highway from New Orleans south to Venice in Plaquemines Parish.