Divide the city into sections so that flooding is limited to smaller areas
Submarines and aircraft carriers are divided into many compartments. Should one begin to leak, crew members can seal hatches and isolate the flooded compartment before the entire vessel sinks. It's a strategy that Joseph Suhayda, former director of the Louisiana Water Resources Research Institute and a retired civil engineering professor, says could be easily incorporated into a new levee system for New Orleans. Under the current system, he says, "there is no internal management of water if the levees fail."
Suhayda's solution is to create an interlocking network of reinforced floodwalls that would divide New Orleans into what he dubs "community havens." "There are natural topographic ridges in the city that could be linked together and subdivided to compartmentalize the city," he explains. "Then if there were a leak or a breach in one place, the water could be confined."
Community haven floodwalls would be less obtrusive than existing earthen levees, which require about three feet of width to support every foot of height. Floodwalls used to partition the city would resemble the narrow concrete sound barriers used to flank freeways. Surface streets would pass through steel floodgates.
Should a storm surge penetrate earthen levees along Lake Pontchartrain, floodgates would be automatically sealed to stop water from spreading south over the city. Suhayda proposes ringing hospitals, power stations, evacuation shelters, police and fire stations, and other essential buildings with a second tier of floodwalls. "You want to make sure that even if the city floods, you're not going to lose the critical sites," he says.
Suhayda estimates the cost to erect a floodwall network at less than $1 billion and says it could be completed in two to three years. "We could join together some of the internal topography in New Orleans," he says, "and immediately provide flood protection."
Even the most attractive floodwalls would change the character of New Orleans-blocking light and views and creating isolated neighborhoods.
The Louisiana-based company Hesco
Bastion has designed a product called the Concertainer that looks like a 15-foot-long ice tray and can be filled with earth or sand and stacked Lego-style. A wall made from Concertainers and positioned along Lake Pontchartrain survived Hurricane Katrina unscathed. But so far, there are no official plans to build similar walls to enclose and protect neighborhoods.
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