Damage to NO from powerful hurricane comparable to Asian t

[sunny]

I don't know if this is the right place to post this or not...
wwltv.com

Damage to city from powerful hurricane comparable to Asian tsunami

10:37 AM CST on Wednesday, January 12, 2005

Dave McNamara / WWL-TV Reporter

An LSU hurricane researcher suggests that if you want to see what could happen to New Orleans during a catastrophic hurricane, the tsunami devastation in Southeast Asia offers a good example. And he says that level of destruction came as close as Hurricane Ivan.

The images of the killer Asian tsunami are haunting, as a river of water rushes through towns and washes away property and lives. LSU hurricane researcher Dr. Ivor Van Heerden says New Orleans could have faced similar destruction and death if last year's Hurricane Ivan had not veered away from Louisiana.

“If you combine that, the wind damage, and damage from waves as well as the surge, we could very well see very significant damage akin to what we've seen with tsunamis in Asia,” said Van Heerden.

Van Heerden has developed a computer model of a category 3 hurricane, which he claims represents just what would happened if Ivan had come ashore at Grand Isle. First, the storm surge would pile up against the outside of the Mississippi River levee in St. Bernard and Plaquemines Parishes.

“We're looking at between 20 and 24 feet of water in this area back up against the artificial levees,” he said.

Then the floodwaters surge up the industrial canal on the East, and the Bonnet Carre Spillway on the West, flooding the city from both directions. Water fills up the inside of New Orleans' hurricane protection levees. A 17-foot high storm surge reaches as far north as I-12 in St. Tammany Parish.

The storm surge that would flood the city would be 11 to 14 feet above sea level, meaning a typical neighborhood that's 5 feet below sea level would be covered with 19 feet of water. Van Heerden says that kind of flooding could kill tens of thousands of people.

“What could have happened with Ivan, would flood so high that you would eventually have to look for a light post or a live oak tree or something to hang onto,” he said.

Van Heerden’s computer model shows that the water would rise in the city at a rate of two feet an hour; not the wall of water we've seen in the Asian tsunami. But that could change if hours of soaking rains and battering waves cause a levee to collapse, something that Van Heerden says has a fairly high probability of happening in a major hurricane.

Add to that, the punishing winds that would tear apart buildings and the toxic chemicals from industries that would mix with the flood waters. Van Heerden is convinced that it's only a matter of time before a hurricane like Ivan doesn't make a last-minute turn away from New Orleans.

“Louisiana, in the last 50 years, has had seven close calls from Ivan size storms,” Van Heerden said.

Unlike countless thousands of people in Southeast Asia who got no warning that a tsunami was heading their way, people in Southeast Louisiana will know a hurricane is coming. Dr. Van Heerden hopes that people here understand why they should evacuate, saying emergency planners need to make sure they provide transportation to evacuate people who don’t own any transportation.

[depotoo]

it's scary isn't it? i've read this before - or the effects a direct hit could have and just pray it never happens.

[Pburgh]

Sunny, I've read this before about New Orleans. The fact that you would have warning is probably negated by the fact the New Orleans flood waters would not recede as quickly as the tsunami waters. The city could be under 15 feet of water for days or weeks.

[sunny]

it's scary isn't it? i've read this before - or the effects a direct hit could have and just pray it never happens.

Oh, no doubt this city would be devestated. I kind of worry after last year's evacuation, though. People complained because we were told to evacuate and got very little of Ivan. I'm afraid that if the order came again this year, it might be ignored by a lot of people. Not by me, mind you. They'll only have to tell me once and I'm out of here.

[depotoo]

i understand - after the first hurricane here a lot did not heed the warning for the next one (3 wks. later) and it wa more ferocious - just didn't last as long. if it had come in as predicted strength wise it could have been devastating - many lives could have been lost!

[sunny]

Sunny, I've read this before about New Orleans. The fact that you would have warning is probably negated by the fact the New Orleans flood waters would not recede as quickly as the tsunami waters. The city could be under 15 feet of water for days or weeks.

One of the biggest problems with evacuating New Orleans is that it would take 72 hours to do a proper evacuation.

The problem with the water would be huge. We have to pump the water out of the streets here. Well, the pumps would be under water, therefore they would not work.

I used to be sceptical about the stories of the river "flowing backwards" until Georges came our way. My brother-in-law is a tug boat pilot, and they always have to move the boats to this little town named "Paulina", which is about thirty miles this side of Baton Rouge. With what little bit of Georges we got, the river rose three feet where he was. That told me everything I needed to know, and I will not take that chance.

[sunny]

i understand - after the first hurricane here a lot did not heed the warning for the next one (3 wks. later) and it wa more ferocious - just didn't last as long. if it had come in as predicted strength wise it could have been devastating - many lives could have been lost!

I am still amazed at the tracks!!

[Derek Ortt]

Georges would have been several times worse than Ivan. Georges was not that much weaker than Ivan (I am not convinced it was weaker at all, but thats for another debate). Not only would we have had wind gusts approaching 100 m.p.h. in NO, it was so slow moving that there would have been up to 30 inches of rainfall in the city as well

Ivan may not have been as bad because of the angle of approach being more from the south than the east so had it have made landfall, the 105KT winds would have been down to no more than 80KT after tracking the 60 miles over land to NO and its fairly fast motion would have resulted in less rainfall.


Now, where NO got the big break was Elena in 1985 or even Erin in 1995. A change in heading of no more than 5 degrees would have resulted in an actual landfall at NO, meaning the cat 3 winds and worst of the surge would have moved directly into the city, which as we found from Pensacola, even strong cat 1 winds and a 10 foot surge is very efficient at leveling parts of a major city

[mobilebay]

Georges would have been several times worse than Ivan. Georges was not that much weaker than Ivan (I am not convinced it was weaker at all, but thats for another debate). Not only would we have had wind gusts approaching 100 m.p.h. in NO, it was so slow moving that there would have been up to 30 inches of rainfall in the city as well

Ivan may not have been as bad because of the angle of approach being more from the south than the east so had it have made landfall, the 105KT winds would have been down to no more than 80KT after tracking the 60 miles over land to NO and its fairly fast motion would have resulted in less rainfall.


Now, where NO got the big break was Elena in 1985 or even Erin in 1995. A change in heading of no more than 5 degrees would have resulted in an actual landfall at NO, meaning the cat 3 winds and worst of the surge would have moved directly into the city, which as we found from Pensacola, even strong cat 1 winds and a 10 foot surge is very efficient at leveling parts of a major city

You can look at all the Data you want. This is a fact. I was on the East side of Georges, and on the West side of Ivan. Ivan was BY FOR the worst of the two(wind).

[sunny]

Georges would have been several times worse than Ivan. Georges was not that much weaker than Ivan (I am not convinced it was weaker at all, but thats for another debate). Not only would we have had wind gusts approaching 100 m.p.h. in NO, it was so slow moving that there would have been up to 30 inches of rainfall in the city as well

Ivan may not have been as bad because of the angle of approach being more from the south than the east so had it have made landfall, the 105KT winds would have been down to no more than 80KT after tracking the 60 miles over land to NO and its fairly fast motion would have resulted in less rainfall.


Now, where NO got the big break was Elena in 1985 or even Erin in 1995. A change in heading of no more than 5 degrees would have resulted in an actual landfall at NO, meaning the cat 3 winds and worst of the surge would have moved directly into the city, which as we found from Pensacola, even strong cat 1 winds and a 10 foot surge is very efficient at leveling parts of a major city

You can look at all the Data you want. This is a fact. I was on the East side of Georges, and on the West side of Ivan. Ivan was BY FOR the worst of the two(wind).

I have to agree with Derek. New Orleans got more out of Georges than we did Ivan.

[Derek Ortt]

Ivan went closer to Mobile than did Georges (Georges destructive winds were concentrated around the eye wall, outside of those, there were no hurricane force sustained winds), which is why there was more wind in Mobile (surge, well, water street earned its name during Georges)

[sunny]

Ivan went closer to Mobile than did Georges (Georges destructive winds were concentrated around the eye wall, outside of those, there were no hurricane force sustained winds), which is why there was more wind in Mobile (surge, well, water street earned its name during Georges)

I knew that I really did!

[Rainband]

with a Huirricane there is a warning. Thats the only important difference. Scary

[Derek Ortt]

<i>with a Huirricane there is a warning. Thats the only important difference. Scary</i>

Except in the French Caribbean. Only get 6-9 hours at most

[Rainband]

<i>with a Huirricane there is a warning. Thats the only important difference. Scary</i>

Except in the French Caribbean. Only get 6-9 hours at most

Wow . but thats better than none at all

[Derek Ortt]

in Marilyn in 1995, despite all other islands being under a hurricane warning, Guadeloupe which received the actual landfall, was not put under a warning until after the hurricane made landfall. Kind of like an old time tornado warning, no warning until the tornado is on the ground

[cajungal]

It is true. They showed it on the news. If a major hurricane ever hit New Orleans head on, or veered just a little to the west like the Houma area, it would be devastating. Water would be above the average rooftops. As many as died in the Asian Tsunami, could die in New Orleans. Maybe more. Because a lot won't leave the city. Because of gridlock leaving for Hurricane Ivan, a lot won't leave now. And they figure that since Canes to affect New Orleans directly are extremely rare. Most veer off to the east at the last minute and hit either the MS Coast or the Florida panhandle. And you could also kiss my area (Terrebonne Parish) goodbye. We are 60 miles below New Orleans and the erosion is severe here.

[sunny]

It is true. They showed it on the news. If a major hurricane ever hit New Orleans head on, or veered just a little to the west like the Houma area, it would be devastating. Water would be above the average rooftops. As many as died in the Asian Tsunami, could die in New Orleans. Maybe more. Because a lot won't leave the city. Because of gridlock leaving for Hurricane Ivan, a lot won't leave now. And they figure that since Canes to affect New Orleans directly are extremely rare. Most veer off to the east at the last minute and hit either the MS Coast or the Florida panhandle. And you could also kiss my area (Terrebonne Parish) goodbye. We are 60 miles below New Orleans and the erosion is severe here.

They said that after Georges, too. BUT - they did leave for Ivan. Let us hope they will once again heed the warning to leave, if it should come down.

[cajungal]

We did not leave for Ivan. Never evacuated before in my life. My dad kept insisting on heading for central Louisiana. But, we still never actually left. A lot of people down here in Terrebonne Parish don't leave. They are stubborn and I guess they are tired of leaving their homes. Because the storms almost always turn away from us at the last minute. But, I know another Betsy will happen in our lifetime.

[MGC]

Dereck, for your information, there is not 60 miles of land between New Orleans outter levee system and water. In places the levee starts where the water ends. What little land is nothing more than marsh scant inches above mean high tide. Having witnessed both Georges and Ivan, I'd have to agree that a large slow moving hurricane that approaches NO from the SE is the biggest threat. Of course, a powerful hurricane moving north up Barataria Bay would also cause major flooding. I was a young child when Betsy moved just south of New Orleans. At least Betsy was moving fast. At the time of Betsy, the levee system was much less than it is today. Basically, the levees were dirt with grass holding it all together. The levees were breeched in a couple of spots in St Benard Parish to the east of downtown NO. Water reached the roofs of houses. If I had to choose between flooding by rain or a breached or topped levee I'd take the rain. At least todays levees are reinforced with concree in vernable areas. If a large hurricane of both intensity and area would hit NO than there would be a big mess. The coast line from Mississippi to the mouth of the river would trap water. The surge of an Ivan type hurricane would be far higher than the surge observed in Pensacola since the water would have nowhere to flow away down the coast. NO has dodged many a hurricane since 1965..........MGC