September 01, 2005

Forewarning didn't help

Yesterday L.A. Observed pointed out the amazing five part special report Washing away from The Times-Picayune in 2002. What really struck me was this passage from The Big One, one of the articles from the second part of the series which seems to have described the events from Katrina with remarkable foresight.

"So now the lake is 5 to 8 feet higher than normal, and we're talking about a lake that's only 15 or 20 feet deep, so you're adding a third to a half as much water to the lake," Suhayda said. As the eye of the hurricane moves north, next to New Orleans but just to the east, the winds over the lake switch around to come from the north.

"As the eye impacts the Mississippi coastline, the winds are now blowing south across the lake, maybe at 50, 80, 100 mph, and all that water starts to move south," he said. "It's moving like a big army advancing toward the lake's hurricane-protection system. And then the winds themselves are generating waves, 5 to 10 feet high, on top of all that water. They'll be breaking and crashing along the sea wall."

Soon waves will start breaking over the levee.

"All of a sudden you'll start seeing flowing water. It'll look like a weir, water just pouring over the top," Suhayda said. The water will flood the lakefront, filling up low-lying areas first, and continue its march south toward the river. There would be no stopping or slowing it; pumping systems would be overwhelmed and submerged in a matter of hours.

"Another scenario is that some part of the levee would fail," Suhayda said. "It's not something that's expected. But erosion occurs, and as levees broke, the break will get wider and wider. The water will flow through the city and stop only when it reaches the next higher thing. The most continuous barrier is the south levee, along the river. That's 25 feet high, so you'll see the water pile up on the river levee."

As the floodwaters invade and submerge neighborhoods, the wind will be blowing at speeds of at least 155 mph, accompanied by shorter gusts of as much as 200 mph, meteorologists say, enough to overturn cars, uproot trees and toss people around like dollhouse toys.

The wind will blow out windows and explode many homes, even those built to the existing 110-mph building-code standards. People seeking refuge from the floodwaters in high-rise buildings won't be very safe, recent research indicates, because wind speed in a hurricane gets greater with height. If the winds are 155 mph at ground level, scientists say, they may be 50 mph stronger 100 feet above street level.

The graphic packages are worth taking a look at, especially one on the bowl that looks at how a hurricane could effect the area and another on the levees.

Our knowledge of the looming danger in southern Louisiana didn't help in any real way to make the for a better outcome (except for the insurance businesses that bailed out of the region once the writing was on the wall).

Posted by Dave at September 1, 2005 03:23 PM
Trackback URL: http://homie.dijas.com/mt/mt-tb.cgi/507
Comments

Too true.

Posted by: Daniel Morris on September 8, 2005 04:30 PM commLink