Thursday, July 30, 2009

Uncertain levees and the aftermath of Hurricane Katrina

Matthew Cardinale in IPS: Today, the population of New Orleans is still about 175,000 people fewer than it was before Hurricane Katrina hit four years ago next month. Along with concerns about jobs and housing costs, the city's vulnerability to flooding has weighed heavily on the minds of many evacuees, many of whom have not returned.

In the first part of this series, IPS explained how the levees are being built up to a new standard of protection - essentially 99 percent protection each year - scheduled to be completed by the end of 2011, and that Holland, by comparison, uses a higher standard of 99.99 percent protection.

Unfortunately, most New Orleanians, both current residents and in the diaspora, have very little understanding of what level of protection is being promised. Neither the local nor national media have asked the tough questions, said Sandy Rosenthal, executive director of Levees.org.

People in New Orleans see work being done on the levees, but they generally sense that the level of protection being promised would not be strong enough to handle another hurricane on the scale of Katrina. The street wisdom is that the new levees might be strong enough for a Category 3 or 4 hurricane, but certainly not a 5.

In reality, the scale which measures hurricanes in categories 1 through 5, the Saffir-Simpson scale, speaks to intensity or wind speed, not to flood levels, the latter of which are more important to the issue of levee protection, several experts told IPS. Ed Link of the Interagency Performance Evaluation Task Force, which studied the Hurricane Katrina levee failures, said the scientific community is debating whether to create a new category system that is both meaningful and that people can understand. He declined to identify a category level which would describe the level of protection, using Saffir-Simpson, that would be offered by the new levees....

New Orleans flooded by Hurricane Katrina in 2005

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