“The whole of New Orleans is being evacuated”:http://www.nytimes.com/2005/08/28/national/29katrinacnd.html as “Hurricane Katrina”:http://www.nhc.noaa.gov/text/index_hls2.shtml moves toward the coast. It’s been known for a long time that New Orleans could be devastated by a hurricane under just the right (meaning, very, very wrong) circumstances. The city is located in a bowl-shaped depression with water on three sides, and under the “worst-case”:http://www.findarticles.com/p/articles/mi_m0BJK/is_15_11/ai_68642805 “outcome”:http://americanradioworks.publicradio.org/features/wetlands/hurricane1.html, if it flooded severely it would be tremendously difficult to get rid of the water. There’s a scholarly literature on the danger. “One government report says”:http://water.usgs.gov/wrri/02grants/prog-compl-reports/2002LA4B.pdf:

bq. New Orleans is the most vulnerable major city on the Gulf Coast and perhaps in the entire United States. Had Hurricane Georges not taken a last minute turn to the east in 1998, major portions of New Orleans would have flooded. It would likely have been one of the worst disasters of the century in terms of loss of life and damage. Additionally, Louisiana has extensive infrastructure of oil and gas facilities, chemical plants, and hazardous, industrial and residential landfills. Most of these facilities are in flood prone areas and within the confines of levee systems protecting housing and other structures from flooding. Even in areas where mitigation strategies have been engineered (i.e., levee, drainage, and pumping systems), such designs are unable to capture and control all storm water runoff from occasional extreme rain events.

“Another, from LSU,”:http://www.publichealth.hurricane.lsu.edu/Adobe%20files%20for%20webpage/LevitanHurrVulnBR&NO.pdf, tries to map the likely range of flooding from a category 2 or 3 storm. It’s not pretty. Hopefully things won’t go so badly, of course. But then again it might be the biggest thing to hit the region since the “Great Mississippi Flood”:http://www.amazon.com/exec/obidos/ASIN/0684840022/kieranhealysw-20/ref=nosim/ of 1927.

_Light Relief Update_: In the “CNN story on this event”:http://www.cnn.com/2005/WEATHER/08/28/hurricane.katrina/index.html, the mayor of New Orleans is quoted as saying “About 70 percent of New Orleans is below sea level, and is protected by a series of levies.” I’m sure our “libertarian friends”:http://www.highclearing.com/ would heartily endorse this statement, but I don’t think the transcript quite conveys the mayor’s meaning.