My suspicion is that either the cost is too great, or that it doesn’t help the far-flung residential neighborhoods.
But it still seems to me feasible that the most important areas of New Orleans could be jacked up in the way that Galveston was a century ago, or significant parts of Venice are today.
Why am I wrong?
Well, for starters, the underlying land isn’t bedrock, it’s just sediment, so as long as the weight remains there, it will continue to sink. Jacking things up would be a (difficult, expensive) temporary solution, but it would just be prolonging the inevitable.
Yes, like Smeghead said (hey that rhymes) the soft marshland soil will still compact.
I take it this is different from Galveston and Venice?
New Orleans sits on a huge alluvial fan of silt that is so heavy it is actually pushing down on the bedrock.
Normally the spring floods would replenish the silt. However, the levees that line the Mississippi River prevent this natural process from occurring. The city will continue to sink under its own weight as well as the alluvial fan.
There is nothing we humans can to to mitigate this, except move out of the delta.
Much wiser and knowledgeable posters have given technical reasons why the idea isn’t feasible or possible, but it should also be noted that New Orleans is a city with very little in the way of financial resources. The New Orleans public schools, for instance, are notoriously ill-equipped and has a crumbling infrastructure. They can’t raise a bond because there is no way to finance it through public money. It’s really tragic.
[fantasy]Set up a “silt pump” (which I’ve just invented, patent application pending), which is powered by a spinner sunk in the Mississippi current, and which sucks up the thickest flowing mud at the bottom of the river. This slurry is piped over the levee into an area, say one city block at a time per pump. The area is dammed to constrain the solids, and the water is pumped back out by the city’s existing pumps.
The first areas chosen are the blocks where few or no buildings are salvageable. As each block fills up to the height of the levee, add a new dam for the next block.
As you get to salvageable buildings, jack them nice and high and let the mud fill in underneath. Pour foundations and set’em down glossing over minor technical details here, such as mud settling*. Line the Miss. shore with these silt pumps until New Orleans has been levitated.[/fantasy]
[fantasy#2] The gummint buys out all the property in New Orleans, declares a new N.O. nearby, moves a lot of earth in raise that to 20’ above the surrounding, and sells lots in the new N.O. to all the original owners by preference. Even zones the new N.O. as French Quarter, etc. Probably cheaper and quicker than fantasy #1, but not as cool.[/fantasy]
End fantasy for sure, as this type of move was suggested in Santa Cruz after the '89 earthquake, and in the Oakland Hills after the great fire, and in both cases no one would go for it. In both those cases, the areas are sure to repeat the same disasters over time. We appear to be dealing with humans here.
*You could probably deal with the settling issue by some move such as putting vibrators to work jiggling the water out of the settling mud, giving a nice dense non-squishable packed silt.
Nice try, but silt/sediment will not compact. The soil particles are too fine. Also, there is not enough clay material to give cohesion - that element which holds soil particles together. Didn’t you play on the creek bank as a child? Even a child knows you can’t build on mud. (no offense intended, Mary.)
Now seems like a good time to do so, right? Being that my news is Mexican, all I get are the fantastic scenes – nothing deeper that I’d get at home. Is there any talk of just abandoning the place among credible experts? Yeah, I know, next we abondon Florida and then California and then tornado alley – but we could squeeze everyone else in the rest of the country. Just a shame that I’ve never gotten around to going to Mardi Gras.
Well, we could ring the city with a dozen nuclear plants, use the energy to liquify nitrogen from the atmosphere, and pump that down hundreds of wells into the muck underlying the city. The resultant ice lens would provide a stable ‘bedrock’ upon which to rebuild.
I’ve heard this idea of relocating the city. It seems so far-fetched. Would the buildings be moved or abandoned or torn down? What would it cost?
You’re a little over a century too late to get a patent. Besides, raising the grade of Galveston took decades (I’m ignoring the 1911 date in that article; my father, born in 1921, had a memory of falling into the slurry and being carried a few blocks before being pulled back onto the catwalks.) Galveston also had the advantage of being built on sand, not silt. The organic soil that New Orleans lays on compacts only slightly better than a pile of leaves compacts. I’m exaggerating, but the soil is not stable.
By the way, they did jack up the buildings in Galveston… using screw jacks. Somewhere out there is a picture of a school or other large brick building held over six feet off of the ground with screwjacks and cribbing. To raise it, they dug a series of tunnels under the building. Once the jacks and workers were in place, a worker outside the building started slowly beating a drum. Evey time he hit the drum, all of the laborers under the building put a quarter turn on their screw jacks.
One of the cities just South of St. Louis MO was relocated after on of the major floods. Flooded town abandoned and completely re-established on higher ground nearby.
Valmeyer was the town and more information is located here: http://www.sustainable.doe.gov/freshstart/case/valmeyer.htm
And here: http://maps.google.com/maps?oi=map&q=Valmeyer,+IL you can see the old town on the left that’s beed abandoned and to the right, on higher ground, the new town.
Yes, but New Orleans is considerably larger than that town. Regular homeowner’s insurance doesn’t cover floods, so I wonder how many people in New Orleans had flood insurance.
What do common, middle-class landowners do when the whole town is relocated? I can’t imagine that the federal government just swaps land one-for-one with everyone, right?
Heck, there is plenty of room in the state of Dakota.
Never heard of it.
My point exactly.
You mean that the Dakota Territory is a state now?
There’s actually two Dakotas now. The one on the South, where their motto is “At least it’s not North Dakota”, and the one on the North who’s motto could be “Oh yeah!”