DigitalKoans

After the New Orleans Hurricane Katrina disaster, I'm sure that awareness about the possibility of long-lasting devastation from U.S. hurricanes increased significantly. After all, who could have imagined that the U.S. response to such a catastrophe would be so pathetic?

About a month after Katrina, Houston was threatened by Hurricane Rita, and the panic was unbelievable as millions tried to flee, creating one of the most massive traffic jams in U.S. history, with cars stranded by the thousands as they ran out of gas idling in gridlock and local service stations were closed or dry as a bone. Again, officials were slow to act, and in-town trips that would normally take about 15 minutes took as long as 12 hours.

Why the panic? To some degree, I'm sure that it was fueled by media images of Hurricane Katrina; however, it was also driven by the potential devastation that a Category 4 or 5 hurricane would cause in Houston.

For those of you who don't have the Saffir-Simpson Hurricane Scale memorized, here's what the National Weather Service says about Category 4 and 5 hurricanes (Katrina was a Category 3 hurricane):

Category Four Hurricane:

Winds 131-155 mph (114-135 kt or 210-249 km/hr). Storm surge generally 13-18 ft above normal. More extensive curtainwall failures with some complete roof structure failures on small residences. Shrubs, trees, and all signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows. Low-lying escape routes may be cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of structures near the shore. Terrain lower than 10 ft above sea level may be flooded requiring massive evacuation of residential areas as far inland as 6 miles (10 km). . . .

Category Five Hurricane:

Winds greater than 155 mph (135 kt or 249 km/hr). Storm surge generally greater than 18 ft above normal. Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. All shrubs, trees, and signs blown down. Complete destruction of mobile homes. Severe and extensive window and door damage. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of all structures located less than 15 ft above sea level and within 500 yards of the shoreline. Massive evacuation of residential areas on low ground within 5-10 miles (8-16 km) of the shoreline may be required.

Here's a map showing the greater Houston and Galveston areas' evacuation zones.

Here's a PDF file that shows this in more detail.

Here's an explanation of the zones (zone C is the zone closest to Houston):

For example, those in Evacuation Zone C should plan to evacuate for a Category 4 or 5 hurricane. Those in Evacuation Zone B should plan to evacuate for a Category 3, 4 or 5 hurricane. Those in Evacuation Zone A should plan to evacuate for all hurricanes.

To understand the reason why there are such large-scale evacuation plans, read this article, which discusses how severe hurricane damage could cost up to $50 billion: "Models Show 'Massive Devastation' in Houston."

That's why Houston worries about hurricanes, especially Category 4 or 5 ones.

This entry was posted on Saturday, August 18th, 2007 at 12:46 pm and is filed under Houston. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.