Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Monday, May 16, 2011

The hundred-year flood

Are there some places in the world that people just shouldn't live?

I am watching with some horror as the floodwaters of the Mississippi River continue their slow progression down into my home state of Louisiana.  The opening of the Morganza Spillway, done ostensibly to protect the much larger population of New Orleans, will release those floodwaters into the Atchafalaya Basin, home of thousands of people in little towns like Morgan City, Henderson, and Butte Larose.

All of this, of course, demands a question that few of us are willing to ask.  Should people be living in these areas in the first place?  New Orleans included?

The levy and spillway system, designed by the Army Corps of Engineers in the early 20th century, was intended to keep the Mississippi River in its course.  The Mississippi has been "trying" to change course for hundreds of years -- this is a completely natural process, in which progressive silting and extension of the delta effectively raise the mouth of the river, slow down water flow, and gravity impels the river to find a shorter course.  That shorter course is through the Atchafalaya Basin Swamp and out into the Gulf of Mexico through Atchafalaya Bay.

Of course, such a switch would leave New Orleans high and (relatively) dry, commercially irrelevant as a seaport.  Politicians and business leaders declared that there was no way could that be allowed to occur.  So levies were built to hold the river to its present path, with spillways to accommodate periodic flooding.

This created more problems than it solved.  The levies didn't stop the silting; in fact, it made it worse, because silt that would have been deposited on the lands surrounding the river during floods was now deposited on the river bottom and delta, further raising the bottom of the river (and thus its water level).  So the levies had to be raised to match.  Simultaneously, the installation of huge pumping systems to deal with the saturated soil in New Orleans caused the entire city to subside, just as a sponge shrinks when it dries out.

The city is sinking; the river is rising.  The response?  Raise the levies again.  When you're done, raise them some more.  There are parts of New Orleans that are now over ten feet below the level of the river.

And then Katrina came along, and showed that the people who had said fifty years ago that this was a bad idea were actually right.

But this hasn't stopped the building and reinforcement of levies; it hasn't stopped politicians in Louisiana from pretending that this is a problem that is fixable.  What no one wants to say is that maybe it's time to make the politically inexpedient call that there are places in this world where people just shouldn't live.  The canyon walls of California, the sides of volcanoes in Indonesia, the barrier islands of the Carolinas -- all are places where the risks are known, and excessive, and yet we still live there, crossing our fingers and hoping that nothing bad will happen.

Don't get me wrong; I am far from immune to the emotional side of the tragedy that is unfolding in Louisiana.  I haven't lived there for thirty years, but I remain a Louisianian to the core still.  The idea of abandoning places where my ancestors have lived for two hundred years is a devastating idea.  But shouldn't knowledge sometimes trump sentiment?  There is no way to fix this problem; that is certain.  Also certain is the fact that what we are currently doing is progressively making the problem worse.  A "hundred-year flood," like the one currently occurring, or (worse) another major hurricane, could exact a human toll that is unacceptable given our prior knowledge of the risks. 

We have a poor track record for listening to the people who know the most about the problems we face.  Scientists who warn of inconvenient and expensive potential disasters on the local, national, or global scale become Cassandras, warning of dangers and going unheard.  Perhaps in this case, it's time to listen.  The politicians may be cheered for saying "New Orleans will rise again" -- but unfortunately, the reality is that it is sinking.  Are we prepared to see "hundred-year floods" become a yearly event?

1 comment:

  1. Weren't you just talking about this in APES the other day?

    ReplyDelete