Today, the Mississippi writes a parable about going
with the flow. The University of Houston's College
of Engineering presents this series about the
machines that make our civilization run, and the
people whose ingenuity created them.
Geologist John McPhee stands
on the banks of the Mississippi. He watches a boat
leave the river, enter locks, and drop 33 feet into
a channel called the Old River. That, of course, is
all wrong. This is where the watershed of half our
nation reaches the sea. It's a watercourse that can
reach flow rates of two million cubic feet per
second. The idea that it lies above the surrounding
landscape is more than all wrong. It's downright
frightening.
Downriver, the Mississippi meanders through Baton
Rouge, New Orleans, and all the industry in
between. This region has been called America's Ruhr
Valley -- it is so rich in industry.
But here the Mississippi has built its own bed too
high, and is ready to leave it. That threat has
been mounting steadily. By WW-II, a third of the
Mississippi was overflowing into the Old River and
from there to the Atchafalaya River. The
Atchafalaya meanders down through the Cajun
parishes of south central Louisiana. It was about
to become the outlet of the Mississippi. The Corps
of Engineers responded by building dams and locks.
The Mississippi has been jumping about like that
for thousands of years. Most of Louisiana is made
of sand and silt dumped by the River. The
Mississippi was shifting its bed during the Trojan
Wars. It was shifting again while the Romans built
their aqueducts. The Battle of Hastings occurred
during its last major move.
Today, a striking feature of the Louisiana map is a
long arm of land reaching from New Orleans to the
southeast, far into the Gulf -- the lengthening bed
of the Mississippi. That arm of silt was a mere
stump in my 1898 Britannica.
Ever since the mid-19th century, we've managed to
hold the restless River in that place. At first
slaves built levees and embankments. When the work
proved too dangerous to risk capital property, the
task went to Irish immigrants. All the while,
cities grew up along the River. Today, industries
that must be served by ocean trade march a third of
the way into the state.
We've contained the Mississippi's attempt to move
for a while. But move it will -- sooner or later.
One big flood and it will break through those
fragile barricades to reach the low ground it
hungers for. When that happens, two hundred miles
of fresh-water ports will be left dry, unless we
cut a salt-water trench across Louisiana.
Many observers look on attempts to hold the
Mississippi as pure hubris. One says, The three
most arrogant human projects imaginable are, in
descending order, to steal the sun, to make the
rivers run backward, and to contain the
Mississippi.
The longer we hold this tiger by the tail, the more
committed we are to a task that's more difficult
every year. The Mississippi warns us, yet again,
that nature's intent is inexorable. Nature will
yield to our will -- but only so far, and only for
a while.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
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