NationStates Jolt Archive

According to CNN, the 9th ward of New Orleans is flooding again thanks to Rita.




Phoey.

I hope they don't just rebuild the city. Move it inland a bit, or rebuild it on higher ground. This crap's just going to keep happening if they don't.

I hope they don't just rebuild the city. Move it inland a bit, or rebuild it on higher ground. This crap's just going to keep happening if they don't.

I must agree.. definitely in land or on higher ground. I'm sorry but who had the bright idea of building it below sea level? Look at Houston.. it is very much in land... even Galveston has protection against 17 foot storm surge.

They should at least rebuild with shutters and strengthen the levvy system. The buildings that were built old school French styled apparently held up at least in part because of the shutters.

Do what you did in Seattle and build a new street level a few floors up.

The French Quarter survived, because the original Orleans Parish was built above sea level. It was afterwards when we started expanding, that foolish construction began.

You can perfectly well live below sealevel. About ten million Dutch prove that on a daily basis. But you gotta be sure that the dikes and levees are in good condition.

You can perfectly well live below sealevel. About ten million Dutch prove that on a daily basis. But you gotta be sure that the dikes and levees are in good condition.

Yeah, but when was the last time they were hit with a category 4 hurricane?

You can perfectly well live below sealevel. About ten million Dutch prove that on a daily basis. But you gotta be sure that the dikes and levees are in good condition.
You've got to be sure the taxpayers are willing to shell out the cash before building the dikes. Apparently the government in Louisiana didn't think they could raise the funds for dikes as good as those in the Netherlands, so they let a hurricane raze the city instead.

Yeah, but when was the last time they were hit with a category 4 hurricane?

If the defences are sufficent then they should be fine. The dykes/levees just need to be up to scratch.

Its an expensive lesson but a valuable one none the less.

Yeah, but when was the last time they were hit with a category 4 hurricane?
Levies or dikes are rated according to how often an event likely to breach them can be expected. The NO levies were rated at 100 years. The Duch ones are rated at 10,000 years. They could sustain a category 5 hurricane.

If the defences are sufficent then they should be fine. The dykes/levees just need to be up to scratch.

Its an expensive lesson but a valuable one none the less.

I agree, the defences are to blame, the location simply exarcapates the problem.

New Orleans relies on huge pumps every time it rains, just to pump the water out of the streets. At full cpapacity they can pump 1 inch of water per hour.

The problem is that only 23 of the 48 pumps are functioning. The heavy rain from Rita will compound the job of pumping out the city, and the swollen Lake Pontchartrain pressures the levees and canals.

The most dangerous time is a day or two after the storm because it takes a while for the watershed to fill the lake.

That's two Category 5 hurricanes this month. It's starting to turn into 2004 all over again.

I talked about this editorial on another thread, but I didn't have the link--I found it today (http://www.nytimes.com/2005/09/02/opinion/02fischetti.html?ex=1283313600&en=46e397319b1b7011&ei=5090&partner=rssuserland&emc=rss), and I'll excerpt the ideas below:

What can we do to restore these natural protections? Although the parties that devised Coast 2050, and other independent scientists and engineers who have floated rival plans, may disagree on details, they do concur on several major initiatives that would shield New Orleans, reconstitute the delta and, as a side benefit, improve ports and shipping lanes for the oil and natural gas industries in the Gulf of Mexico.

Cut several channels in the levees on the Mississippi River's southern bank (the side that doesn't abut the city) and secure them with powerful floodgates that could be opened at certain times of the year to allow sediment and freshwater to flow down into the delta, re-establishing it.

Build a new navigation channel from the Gulf into the Mississippi, about 40 miles south of New Orleans, so ships don't have to enter the river at its three southernmost tips 30 miles further away. For decades the corps has dredged shipping channels along those final miles to keep them navigable, creating underwater chutes that propel river sediment out into the deep ocean. The dredging could then be stopped, the river mouth would fill in naturally, and sediment would again spill to the barrier islands, lengthening and widening them. Some planners also propose a modern port at the new access point that would replace those along the river that are too shallow to handle the huge new ships now being built worldwide.

Erect huge seagates across the pair of narrow straits that connect the eastern edge of Lake Pontchartrain, which lies north of the city, to the gulf. Now, any hurricane that blows in from the south will push a wall of water through these straits into the huge lake, which in turn will threaten to overflow into the city. That is what has filled the bowl that is New Orleans this week. But seagates at the straits can stop the wall of water from flowing in. The Netherlands has built similar gates to hold back the turbulent North Sea and they work splendidly.

Finally, and most obviously, raise, extend and strengthen the city's existing but aging levees, canal walls and pumping systems that worked so poorly in recent days.
The author, Mark Fischetti, is a contributing editor to Scientific American magazine.

So that's a place to start, at least as far as ideas are concerned.