Geography Reference
In-Depth Information
The reports that followed the disaster highlighted serious shortcomings in the
design, implementation and maintenance of the flood protection system the walls of
which were, in fact, much lower than previously thought. Their continuity was
compromised and their foundations were, in places, much less deeply rooted than
required by engineering specifications. In 2005, the Hurricane Protection System
(HPS) remained unfinished as a result of irregular federal funding cut in half by the
Bush administration.
In addition, local governments could not always pay the 30% co-share of funding
for which they were responsible. It was for this reason that the Orleans Levee
Board
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opposed construction of floodgates on the Dutch model (the Barrier Plan)
resulting in the plan's abandonment in 1977. While the 1966 draft proposal called
for raising protection capable of withstanding “bi-centenary” flooding, local
authorities pressed for a contingency plan to anticipate “centenary” flooding
according to 1965 standards and a reference altitude set in 1929.
As it happened, the centenary protection in question was for a Category 3 storm
to occur every 100 years as shown in the records between 1900 and 1956. Hurricane
Betsy (1965) was much more powerful than the “reference hurricane”, but the model
was not updated until 1979.
It is estimated today that the return period for a Category 3 hurricane is 19 years
in New Orleans (see Chapter 1). The possibility of a centenary hurricane should
therefore at least factor in a Category 4 storm with a return period of 80 years.
Improvements, however, were not made, even when a 1983 USGS study showed
that ground elevations had dropped significantly since 1929.
The reference to a centenary flood was, according to Burby [BUR 06], the
paradox of a local government benefiting from federal flood insurance (the National
Flood Insurance Program (NFIP) 1968) while minimizing its own insurance
expenditures.
Finally, non-compliance with specifications for the depth of floodwall
foundations protecting the 17th Street Canal raises at least the suspicion of
corruption and diversion of at least some of the available funds.
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. Management and maintenance of levees is the responsibility of each county (parish).
Management of levees in the metropolitan area is therefore divided into four separate
authorities. The Orleans Levee Board is solely responsible for the levees that protect the city
center, consolidated with its parish (see Chapter 8).
