The Mississippi River, with its sand and silt, has created most of Louisiana, and it could not have done so by remaining in one channel. If it had, southern Louisiana would be a long narrow peninsula reaching into the Gulf of Mexico. Southern Louisiana exists in its present form because the Mississippi River has jumped here and there within an arc about two hundred miles wide, like a pianist playing with one hand—frequently and radically changing course, surging over the left or the right bank to go off in utterly new directions. Always it is the river’s purpose to get to the Gulf by the shortest and steepest gradient. As the mouth advances southward and the river lengthens, the gradient declines, the current slows, and sediment builds up the bed. Eventually, it builds up so much that the river spills to one side. Major shifts of that nature have tended to occur roughly once a millennium. The Mississippi’s main channel of three thousand years ago is now the quiet water of Bayou Teche, which mimics the shape of the Mississippi. Along Bayou Teche, on the high ground of ancient natural levees, are Jeanerette, Breaux Bridge, Broussard, Olivier—arcuate strings of Cajun towns. Eight hundred years before the birth of Christ, the channel was captured from the east. It shifted abruptly and flowed in that direction for about a thousand years. In the second century a.d., it was captured again, and taken south, by the now unprepossessing Bayou Lafourche, which, by the year 1000, was losing its hegemony to the river’s present course, through the region that would be known as Plaquemines. By the nineteen-fifties, the Mississippi River had advanced so far past New Orleans and out into the Gulf that it was about to shift again, and its offspring Atchafalaya was ready to receive it. By the route of the Atchafalaya, the distance across the delta plain was a hundred and forty-five miles—well under half the length of the route of the master stream. For the Mississippi to make such a change was completely natural, but in the interval since the last shift Europeans had settled beside the river, a nation had developed, and the nation could not afford nature. The consequences of the Atchafalaya’s conquest of the Mississippi would include but not be limited to the demise of Baton Rouge and the virtual destruction of New Orleans. With its fresh water gone, its harbor a silt bar, its economy disconnected from inland commerce, New Orleans would turn into New Gomorrah. Moreover, there were so many big industries between the two cities that at night they made the river glow like a worm. As a result of settlement patterns, this reach of the Mississippi had long been known as “the German coast,” and now, with B. F. Goodrich, E. I. du Pont, Union Carbide, Reynolds Metals, Shell, Mobil, Texaco, Exxon, Monsanto, Uniroyal, Georgia-Pacific, Hydrocarbon Industries, Vulcan Materials, Nalco Chemical, Freeport Chemical, Dow Chemical, Allied Chemical, Stauffer Chemical, Hooker Chemicals, Rubicon Chemicals, American Petrofina—with an infrastructural concentration equalled in few other places—it was often called “the American Ruhr.” The industries were there because of the river. They had come for its navigational convenience and its fresh water. They would not, and could not, linger beside a tidal creek. For nature to take its course was simply unthinkable. The Sixth World War would do less damage to southern Louisiana. Nature, in this place, had become an enemy of the state.
- John McPhee, The Control of Nature: Atchafalaya : The New Yorker
McPhee captures the deep hubris of the US Corps Of Engineers trying to control the Missippippi from going where it wants, or more specifically, to block the monstrous waters of the Missippippi from shortcutting through the Atchafalaya to the Gulf of Mexico.
Inevitably, some series of events will lead to the Missippippi jumping its current banks, pushing past our fragile impediments to the river's headlong flight, and leave New Orleans and Baton Rouge castaways in an alluvial plain, river cities no more.
The current flooding is much like that of 1973, when torrential rains in the norther tributary regions had led to a perfect storm, and the Corps of Engineers nearly lost the river to the enticements of the low and empty Atchafalaya.
Today, the Corps of Engineers are letting water flow from the river into the Atchafayala to spare New Orleans, where the flood waters are predicted to reach 19.5 feet, with levees of 20 feet: a difference too close to contemplate.
Somewhere in their workings, though, the Corps is increasing the enduring risk: that something will go wrong, and they will loose the river. A barge, lost to the flood, smashing into the Old River Control of the monumental containment system that the Corps has built and maintained for decades, well, that could lead to an escape. And once the might Missippippi has jumped, the river will not come back. Or not in our lives, at the very least.
It has wandered as far west as Texas, and east as well. As McPhee concludes,
The water attacking Old River Control is of course continuous, working, in different ways, from both sides. In 1986, one of the low-sill structure’s eleven gates was seriously damaged by the ever-pounding river. Another gate lost its guiding rail. When I asked Fred Smith, the district geologist, if he thought it inevitable that the Mississippi would succeed in swinging its channel west, he said, “Personally, I think it might. Yes. That’s not the Corps’ position, though. We’ll try to keep it where it is, for economic reasons. If the right circumstances are all put together (huge rainfall, a large snowmelt), there’s a very definite possibility that the river would divert—go down through the Atchafalaya Basin. So far, we have been able to alleviate those problems.”
