Sea of Atlantis
The Future City of New Orleans
To demonstrate that human control of nature is an illusion, look no further than the perceived permanence of the Old River Control Structure, 135 miles upriver from New Orleans, Louisiana. Atlantean elite labels and slogans are often so audacious, that their unrealistic goals sound heroic or mythical. Imagine the audacity of using poles stuck in the mud to control the largest river in North America. In anticipation that their designated mounds of earth would stay where expected, the Army Core of Engineers (COE) named it a “river control structure”. Prefacing that moniker, should be the word “temporary”.
- When a Katrinaesque hurricane makes landfall at New Orleans, resultant storm surge and overflow from Lake Pontchartrain floods much of the city.
- As the storm travels north, it stalls and dumps unprecedented rainfall on the Middle and Upper Mississippi River Valleys.
- When the resulting flood crests at the Old River Control Structure, catastrophic failure ensues, sending one uncontrolled torrent down the Mississippi River Channel and another down the Atchafalaya River.
- As an unprecedented flow reaches New Orleans, the city floods yet again, only this time there are few if any levees still standing to protect it.
In the aftermath of a simultaneous Katrina-style storm surge and a Pakistan-style river flood, New Orleans could well be unsalvageable. After such a super flood, the Mississippi River Channel through New Orleans would become a silt-clogged riverbed, rather than the deep channel of today. Unless stakeholders plan now for decreased reliance on river and port traffic for economic vitality, New Orleans faces the possibility of a flood-induced economic collapse.
Since Katrina in 2005, the federal government has spent an estimated $125 billion in and around New Orleans. As a citizenry, we should now determine how much we plan to spend on any flood prone region. More important, what we wish to accomplish with those funds? As long as the option for rebuilding a full-sized, old style New Orleans is on the table, the cost may well be too high to bear. Currently, few of the local, state or federal stakeholders are willing to downscale their ambitions. Instead, they attempt to resolve the issue with public proclamations, featuring new and soon to be inadequate levees. Dubbed “The Great Wall”, one new storm surge barrier reminds me of the original Great Wall of China. Astronauts report that the original Great Wall is the only manmade structure easily visible from the International Space Station. History showed that those massive bulwarks did little to prevent nomadic groups from entering the Chinese Empire. Likewise, the new Great Walls will not fully protect New Orleans from category-five hurricanes.
Extensive dredging and reworking of the watercourses throughout the Mississippi River Delta have made defending New Orleans more difficult. After it snakes through the city, the Mississippi River deposits almost none of its silt in shallow water. Instead, the river rushes past New Orleans on a fast trip to the Gulf of Mexico. Bypassing any remaining wetlands, the silt plunges deep into the Gulf. On its descent to the seafloor, the silt releases a toxic mixture of fertilizer and chemicals. Suspended in the water column above the silt beds is a vast hypoxic dead zone. Not even bacteria can survive in its oxygen-depleted environment.
In June 2010, the federal government dedicated over $14 billion to rehabilitation of Louisiana wetlands. At the same time, rumor had it that President Obama supported a redirection of the Mississippi River as a mechanism for providing silt to those wetlands. To accomplish that goal, he might order the COE to flip-flop the water delivery ratios at the Old River Control Structure. New Orleans would henceforth receive huge amounts of silt, but far less water. Concurrently, the Atchafalaya River would take its place as the terminal distributary of the Mississippi River. Upon settling downstream from New Orleans, the newly redirected silt would naturally rebuild fisheries, bayous and marshes. In turn, the larger wetlands would form a natural storm surge barrier for the city.
Only the Mississippi River can discharge the silt volume required to rebuild the wetlands. If humans or Nature can slow the velocity of the river, soils from more than a dozen states might begin to precipitate out near New Orleans. Only then would the river become a useful tool for rebuilding the wetlands of the Mississippi River Delta. If ever there was a good argument for letting Nature take her course, this may be it.
As a cultural landmark and a great historical city, I love New Orleans. Sadly, it has now become a poster child for Atlantean mythical thinking. As a society, we must be willing to create an infrastructure and investment strategy for New Orleans that has finite goals and limits. What budgetary amount we agree upon is less important than being realistic about our attempts to control Nature. Once realism returns to the process, scientists and engineers can combine efforts and create appropriate defenses for core locations and critical functions throughout the region.
Although almost no one wants to hear it, New Orleans should utilize its lowest lying and most vulnerable areas as storm surge basins. After relocating low-income residents to safer areas, the city could afford to sacrifice low-lying areas to flooding, while protecting and preserving a more defensible city core. Ultimately, it will be less expensive to provide a Brad Pitt House in a new neighborhood for each low-lying family than to leave entire neighborhoods in peril. Once the lowest lying residents move out, those areas could become parks or urban farms. With no fulltime residents in harm’s way, the cost of future flood protection and reconstruction would be far lower.
Any legitimate plan for New Orleans must recognize the near inevitability of storm surge and river related flooding. Even with a pragmatic plan, rather than a political one, there is no guarantee that a great flood will not inundate New Orleans. The strategy that I suggest would allow a smaller city to survive longer than the current “full city” strategy, while saving both money and the environment in the process.
at 01:43 PM |
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