NEW ORLEANS (Talk1370.com/WWL) -- With a possible storm surge of 15 feet or more projected by the National Hurricane Center, Hurricane Ida could bring water over the tops of the levees protecting the west bank of Jefferson Parish.
If it does, it would be the first time since upgrades to the system made after Hurricane Katrina toppled former levees in 2005, said Nola.com.
A $14.5 billion collection of levees, floodwalls, pumps and gates now rings parts of New Orleans, Jefferson and St. Bernard parishes.
Overall, the area flood system has 350 miles of levees and floodwalls as well as a series of large pumps and gates, including the West Closure Complex, the largest pump station in the world. Officials in the area stressed that the system should be able to withstand the storm.
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“This is a very differently protected city than it was 16 years ago,” said Ramsey Green, New Orleans Mayor LaToya Cantrell’s deputy chief administrative officer for infrastructure, according to Nola.com.
In the new system levees reduce the risk of a storm surge, they do not provide unlimited protection. However, even when overmatched with high water, they should still be left standing.
“People need to know if they’re in an area that could get this surge, they need to be prepared, they need to understand that this is exactly what this system was designed to do,” said Ricky Boyett, a spokesperson for the U.S. Army Corps of Engineers in New Orleans.
“The levees' height is aimed at blocking overtopping from water levels that have a 1 percent chance of occurring in any year, a so-called 100-year event,” said Nola.com. A Category 4 hurricane – which Ida could become – would be greater than a 100-year event.
The average height of the levees is less than 14 feet, said the outlet. This means water could make it over the top during the height of the storm. But, the water would be pumped out by the same systems that would handle rain from the storm and material planted on the levees known as “anchoring” should keep them in place.
“It’s a different system than we had in Katrina. By it being designed to be overtopped, we won’t have the erosion and the scouring that leads to breaching,” Boyett said. “Once that water recedes you’ll still have a levee there. There’s a big difference between a breach where water is running uncontrolled into an area and water coming over the top for a brief period of time.”
Yet, since the levees have never been overtopped, the system hasn’t been real-world tested.
The rest of the levee system is expected to make it through the storm without significant problems, said Nola.com. By the time Ida arrives, the entire network will be closed for the first time since Hurricane Barry in 2019, according to the outlet. The West Bank Authority plans to use the West Closure Complex to protect from Ida, also the second time since Barry.
At this point, three large pumps on New Orleans’ outfall canals into Lake Pontchartrain are not expected to be needed, said Nola.com