The catastrophic aftermath of Hurricane Katrina in 2005 provide many lessons on infrastructure resilience. The threat of storm surges remains because of the city’s average elevation level is six feet (or almost 2 meters) below sea level and being bodies of water surround the city.
In 2005, the 28-foot storm surge that Hurricane Katrina created left some areas of New Orleans flooded. There were breaches on the floodwall due to foundation failure and water over topping the levees.
Learning from Hurricane Katrina experience, New Orleans and the U.S. Army Corps of Engineers’ Hurricane and Storm Damage Risk Reduction System embarked on the Inner Harbor Navigation Canal Surge Barrier or IHNC Surge Barrier project.
Its construction begun in 2008, and with an aggressive four-year timeline to beat. Despite many complications and technical challenges, the barrier was completed ahead of time in 2011. Construction cost reached $1.1 billion. It’s was a simultaneous design and build civil work project.
The IHNC Lake Borgne Surge Barrier is one of the largest civil works project designed and constructed in the US Army Corp’s history. It extends through the Gulf Intracoastal Waterway and the Mississippi River Gulf Outlet near New Orleans.
It was designed to reduce the effect of storm surge and prevents damage to the most vulnerable areas around New Orleans. The barrier specifically protects the surrounding area against storm surge coming from the Gulf of Mexico and Lake Borgne.
The structure consists of three gates that allow vessel passage through a concrete barrier wall, 10,000 feet long and 26 feet high. There’s a complete floodwall closure of the Mississippi River Gulf Outlet. The Seabrook Floodgate was also constructed, another navigation gate in the vicinity of Seabrook that meets and blocks possible storm surge from the Lake Ponchartrain.
With the breaches repaired and fortified, the level of protection in New Orleans is much better than any time in their entire history. The New Orlean’s surge barrier proved its mettle and served its purpose when Hurricane Isaac came in August 2012.
With its complex structural design, the edifice stands as an infrastructure resilience landmark. This year, the infrastructure garnered the 2014 Outstanding Civil Engineering Achievement (OCEA) Award by the American Society of Civil Engineers (ASCE).
Achieving 100-year storm criteria, IHNC is now considered the model of floodgate and floodwall designs all over the world. Now an infrastructure resilience icon, the IHNC Surge Barrier has become the pride of Louisiana and the US.
Calamities will continue to challenge civilization but with infrastructure management experts providing resilience plans and strategies, risks are significantly reduced.
PHOTO CREDIT: Seacity2100; American Society of Civil Engineers