Environmental Engineering Reference
In-Depth Information
Should New Orleans Be Abandoned?
Despite more than 290 years of effort to protect New Orleans, the overall
vulnerability of the city and surroundings to hurricanes has increased.
The bowl-shaped location that is half below sea level along a hurricane-
prone fl at coastline cannot be changed. The vulnerability to disaster is
increased by accelerating subsidence, rising sea level, storm surges, and
the apparent increased frequency of stronger hurricanes. These natural
phenomena have been enhanced by human location decisions; extraction
of groundwater, oil, and natural gas; canal development; loss of barrier
wetlands; global warming; and the design, construction, and failure of
protective structures.
Given the enormous, increasing, and probably insurmountable obsta-
cles facing the residents of southern Louisiana, it may be time to consider
a solution that no politician or government has publicly considered:
abandoning New Orleans and the surrounding smaller communities. The
American public, not as emotionally attached to the city as its residents
are, is willing to consider this step as indicated by a poll in 2005 after
Katrina hit: more than half the respondents (54 percent) said that fl ooded
areas of New Orleans below sea level should be abandoned and rebuilt
on higher ground, a sensible approach if the city is to be saved.
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Extreme rainfalls in the Mississippi River basin are becoming more
common, the city is sinking up to 1 inch per year and is already 17 feet
below sea level in places, the ground is subsiding as the mud it is built
on compacts, and breaks in the earth's crust parallel to the shoreline are
lowering the ground surface. In its 291-year history, major pre-Katrina
hurricanes or fl oods have swamped the city twenty-seven times—about
once every eleven years. Home insurance is prohibitively expensive.
The existing levee system is not only inadequate and sinking, but also
poorly designed and built. In 2006, two independent investigations and
the Corps of Engineers' own $25 million study gave a detailed picture
of fl aws in the planning, design, and construction of the levee system.
The Corps of Engineers blamed the defi ciencies on political infl uences
on engineering decisions over the years and the lack of adequate fi nanc-
ing. An engineering professor at Louisiana State University examined the
levee system and concluded that it was not capable of withstanding even
a category 1 hurricane, much less a category 3 or higher. He noted that
“New Orleans' future is very hard to predict. The big unknown is global
warming. If sea level rises by another meter [3.25 feet] in the next 50 to
60 years, if we see far more of these major hurricanes, we could well
reach a point where we see the need to abandon these cities like New
Orleans.”
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