A Disaster Long in the Making
How man distorted the delicate dance between the delta and the sea
New Orleans sits atop a Mississippi River delta that stretches out past the edge of North America, fading from hard ground to a blot of mud, grass, and water. It's a malleable place without clear boundaries, "a land between earth and sea-belonging to neither and alternately claimed by both," wrote geologists for the Army Corps of Engineers in a seminal 1958 study.
Most of the time, earth and sea exist in a state of low-level flux. Waves pound, ground sinks, marshes and dunes change shape. But every so often, the water erupts: A hurricane pushes the sea far inland, or the river brings a winter's worth of cold rain and melting snow down from the north. The flow sweeps away obstacles in its path, drowning, soaking, and rotting them, sometimes eliminating them altogether.
Despite that constant danger, the river and the delta's proximity to the sea has long lured settlers-first Indians, then Europeans, then people from around the world. Many prospered, even as they faced down floods, mosquitoes, and palmetto bugs. Each generation engineered defenses against high water, only to see them washed away. Then-whether because they wanted to defy nature, prove their ingenuity, or simply forgot about the risks-they started over.
By the start of the 21st century, those defenses had changed the delta into a strange hybrid of the man-made and the natural. Levees had locked the river into its course. The landscape was carved up like a jigsaw puzzle, embedded with concrete, steel, pipes, and electronics. Suburbs stretched for miles. Around this urban blotch sat hundreds of miles of earthen levees, concrete-and-steel floodwalls, gates, and locks-their heights carefully calculated to repel all but the highest floods. An intricate web of canals, pipelines, and pumps was built to expel any water that got in.
Soup bowls. None of this construction destroyed the ancient relationship between the delta and the sea-it just distorted it. Underneath buildings and streets, the marshes were sinking. Closer to the Gulf, where reeds and grass still grew, they were dissolving. Facing fewer natural obstacles, hurricane floods moved farther inland. The levees had turned the city and its suburbs into a set of giant soup bowls-sinking areas rimmed by walls. Centuries earlier, when floods washed over a place, the water would be gone in a day. Now it would be trapped.
In 1999, a computer scientist at the Massachusetts Institute of Technology named Alan Wexelblat posted a message with the Viridian movement-a virtual community devoted to a futuristic melding of ecology, technology, and design. "I don't have a word for this form of disaster, but I bet we see a lot of them in the '00s," he wrote, adding a link to an article headlined "Fecal Explosion Threatens City." The article recounted how, in 1998, Hurricane Mitch had damaged the sewage system of Tegucigalpa, Honduras, causing cracks in culverts and buildups of excrement and gas. Sewage bubbled up into the streets. Nobody knew what to do.
This type of breakdown was different from a natural disaster, Wexelblat wrote. "These Viridian Disaster events will be infrastructural in nature ... They'll be collapse, implosion, failure-type events, rather than explosive, razing-type events. The technical system will tie itself in knots, because the planet really is much bigger/more powerful than these systems were designed to accept."
advertisement
