[Rhodes22-list] Why Rebuild New Orleans?

[Robert Skinner]

Folks:

The following article raises a serious question.
Apparently, New Orleans is doomed regardless of
what resources we throw at it.

Tough, but worthwhile reading.

/Robert Skinner

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Time for a Tough Question: Why Rebuild?

By Klaus Jacob

Washington Post, Tuesday, September 6, 2005; Page A25

It is time to swim against the tide. The direction of 
public discourse in the wake of Katrina goes like 
this: First we save lives and provide some basic 
assistance to the victims. Then we clean up New 
Orleans. And then we rebuild the city. Most will 
rightly agree on the first two. But should we rebuild 
New Orleans, 10 feet below sea level, just so it can 
be wiped out again?

Some say we can raise and strengthen the levees to 
fully protect the city. Here is some unpleasant 
truth: The higher the defenses, the deeper the floods 
that will inevitably follow. The current political 
climate is not conducive to having scientific 
arguments heard before political decisions are made. 
But not doing so leads to the kind of chaos we are 
seeing now.

This is not a natural disaster. It is a social, 
political, human and -- to a lesser degree -- 
engineering disaster. To many experts, it is a 
disaster that was waiting to happen. In fact, Katrina 
is not even the worst-case scenario. Had the eye of 
the storm made landfall just west of the city 
(instead of to the east, as it did) the wind speeds 
and its associated coastal storm surge would have 
been higher in New Orleans (and lower in Gulfport, 
Miss.). The city would have flooded faster, and the 
loss of life would have been greater.

What scientific facts do we need before making 
fateful political, social and economic decisions 
about New Orleans's future? Here are just two:

First, all river deltas tend to subside as fresh 
sediment (supplied during floods) compacts and is 
transformed into rock. The Mississippi River delta is 
no exception. In the early to mid-20th century, the 
Army Corps of Engineers was charged with protecting 
New Orleans from recurring natural floods. At the 
same time, the Corps kept the river (and some related 
canals) along defined pathways. These well-intended 
defensive measures prevented the natural transport of 
fresh sediments into the geologically subsiding 
areas. The protected land and the growing city sank, 
some of it to the point that it is now 10 feet below 
sea level. Over time, some of the defenses were 
raised and strengthened to keep up with land 
subsidence and to protect against river floods and 
storm surges. But the defenses were never designed to 
safeguard the city against a direct hit by a Category 
5 hurricane (on the Saffir-Simpson scale) or a 
Category 4 hurricane making landfall just west of the 
city.

Second, global sea levels have risen less than a foot 
in the past century, and will rise one to three feet 
by the end of this century. Yes, there is 
uncertainty. But there is no doubt in the scientific 
community that the rise in global sea levels will 
accelerate.

What does this mean for New Orleans's future? 
Government officials and academic experts have said 
for years that in about 100 years, New Orleans may no 
longer exist. Period.

It is time to face up to some geological realities 
and start a carefully planned deconstruction of New 
Orleans, assessing what can or needs to be preserved, 
or vertically raised and, if affordable, by how much. 
Some of New Orleans could be transformed into a 
"floating city" using platforms not unlike the oil 
platforms offshore, or, over the short term, into a 
city of boathouses, to allow floods to fill in the 
'bowl' with fresh sediment.

If realized, this "American Venice" would still need 
protection from the worst of storms. Restoration of 
mangroves and wetlands between the coast and the city 
would need to be carefully planned and executed. Much 
engineering talent would have to go into anchoring 
the floating assets to prevent chaos during storms. 
As for oil production, refining and transshipment 
facilities, buffer zones would have to be established 
to protect them from the direct onslaught of coastal 
storm surges.

Many ancient coastal cities of great fame have 
disappeared or are now shells of their former 
grandeur. Parts of ancient Alexandria suffered from 
the subsidence of the Nile delta, and earthquakes and 
tsunamis toppled the city's famed lighthouse, one of 
the "Seven Wonders of the Ancient World."

It is time that quantitative, science-based risk 
assessment became a cornerstone of urban and coastal 
land-use planning to prevent such disasters from 
happening again. Politicians and others must not make 
hollow promises for a future, safe New Orleans. Ten 
feet below sea level and sinking is not safe. It is 
time to constructively deconstruct, not destructively 
reconstruct.

The writer, a geophysicist, is an adjunct professor 
at Columbia University's School of International and 
Public Affairs. He teaches and does research on 
disaster risk management.