A mini-New Orleans? Galveston ponders its vulnerabilities (Houston Chron.)

[highplainsdem]

http://www.chron.com/cs/CDA/ssistory.mpl/metropolitan/3344353


This article was published September 8, but seems more relevant now with Rita's projected track going over Galveston:


As New Orleans discovered last week in Hurricane Katrina's wake, however, walls can fail. So where does this leave Galveston, arguably the country's second-most vulnerable city to a hurricane, behind only New Orleans?

-snip-

While New Orleans counted on its levee system, Galveston's sense of security comes from a 15-foot wall. After the great storm of 1900, which killed 8,000, Galveston's leaders constructed a seawall along much of the island's eastern end. They also raised the city directly behind it from a peak of 8 feet above sea level to about 15 feet.

The island now reaches its highest point at the seawall, gently sloping back to sea level at bayside.

A Katrina-size storm would not destroy the seawall, and indeed the wall would absorb much energy from the biggest, crashing waves. But Katrina's storm surge crested at 22 feet, enough height to easily clear the seawall. And the city has no protection from bayside waters.



I wish I could post the entire article, and I hope people will click on that link to read it. It explains in detail just how vulnerable Galveston is, especially the western end of the island, which is less than 5 feet above sea level.

[babylonsister]

1. This sure doesn't inspire confidence; my fingers

are crossed that Rita goes elsewhere, though I don't want to wish her on anyone. Thanks for the article.

[Silverhair]

2. The problem is that a hurricane is so DAMNED BIG.

Katrina hit N.O. and caused problems in Mobile, AL, over 100 miles away.

If Freeport is hit by the eye, almost the entire Texas coast will get some of the storm, and Galveston is close enough for a big storm surge that could hit the parts that are unprotected.

[Rex]

3. The mayor told the people today to get out!

Is "Good Hair" Parry getting the national guard ready to help out the victims? No confidence at all in Ricky! You guys down on the coast should flee because Perry will only help the well off.

[msongs]

4. storm surge is NOT a wave.......->

My understanding of this is that a storm surge is not a wave with a crest like ones the surfers ride. a 25 foot storm surge is NOT a wave that breaks on the beach and is say 25 feet high at the crest and maybe 100 feet wide at the base.

a storm surge is a general increase in sea level that may be miles wide (25 feet high times 30 miles wide along its highest point times maybe miles from beginning to end..I am making these numbers up but you get the idea).
This surge is pushed ahead of the storm by the surface winds and aggravated by the lower air pressure that allow the ocean as a whole to be sucked up to a higher than sea level height, compounded by storm SURF on top of the surge.

Seems to me a 25 storm surge over this 15 foot barrier would flood the whole place with just a bit less violence than if the city was sea level.

A storm surge is more like a tsunami than a wave.

Msongs
www.msongs.com/clark2008.htm