If New Orleans desires to rebuild on higher ground - I would think they could dredge the Mississippi for the material to build higher. You would be killing 2 birds with 1 stone as the river needs periodic dredging anyway. I know this wouldn't work for the whole city, as the devastation was not complete, but for areas of near total loss, why not? I would think with some work you could put steel beams under the buildings you wanted to keep (French Quarter), and jack them up high enough (20 feet) to put material under them. Skyscrapers, well - no hope for them, or the Superdome, but who knows if those will be reused anyway. In any event, more high ground could create some natural barriers to flooding - would have to have some streets like in San Francisco (steep) to transition, but shouldn't be too bad.

My concern is the toxicity of the Mississippi dredge, but how could it be worse than the streets as they are now?
-- trekbody, Sep 09 2005

Elevation map for New Orleans http://www.gnocdc.org/maps/elevation.html
[ldischler, Sep 09 2005]

Subsidance Effects on a Major Coastal City http://www.beg.utex...dsatlas_v1_2000.pdf
This is Houston, but the principles are similar. [reensure, Sep 22 2005]

The French Quarter and skyscrapers are dry, anyway.

I doubt the dredging could produce enough mass to raise the sunken city even inches. I've been puzzling over this myself; where will the soil come from if flooded communities elect to rebuild on raised earth?
-- gerwitz, Sep 09 2005


The Mississippi delivers a colossal amount of silt every year. The Army Corps of Engineers has constructed shutes in the Mississippi to ensure this is eject far out to sea.

Much more sensible to abandon the shutes, and let the river deliver its silt to the river delta, stopping further erosion.

So although I think trekbody needs to do some more research to hone his/her plan, croissant - s/he is thinking along the right lines.
-- DrCurry, Sep 09 2005


Why would there be no hope for the skyscrapers? Look at the pictures. Except for the Hyatt and a few others that lost windows, what damage do you see?
There was minimal flooding in the Quarter and in the CBD. Very little uptown in the Garden District, in Algiers, or in several other neighborhoods. The idea that New Orleans is below sea level is wrong. Some parts are, sure, but most of the old city is above sea level, by as much as eight feet.
-- ldischler, Sep 09 2005


Even if much of New Orleans is not currently below sea level - the coming decades of predicted ocean rises will change that. This is the time to protect the city for the future - not later. I don't think that every block of the city needs to be "raised" but if you could bring large sections out of the "depths" I think it would protect the city in the future. As for there possibly not being enough material - that doesn't make sense to me - you simply would have to dredge an area the size you wanted to landfill to the depth you want to raise it. There is more than enough square miles of Mississippi mud to accomplish the task. This would easily be replaced by the Mississippi in short order - as detailed from "http://www.nps.gov" Sediment Load: The Mississippi carries an average of 436,000 tons of sediment each day. Over the course of a year, it moves an average of 159 million tons of sediment. Averages have ranged from 1,576,000 tons per day in 1951 to 219,000 in 1988.

I wasn't trying to say there was no hope for the skyscrapers - I was just commenting that you couldn't easily raise them. I think you raise the areas around and when reconstructing buildings try to raise their ground level as well.
-- trekbody, Sep 13 2005


If you look at the elevation map, you’ll see it makes more sense to dredge Lake Pontchartrain, as it's closer to the problem areas.
-- ldischler, Sep 13 2005


It would smell.

Rivermuck, especially from a large river, smells.
-- DesertFox, Sep 13 2005


How long do you think it would smell - once exposed to the air, the organisms would start breaking down wouldn't they? I would think a few days/weeks of smell - would be tolerable - especially since you would eventually be covering it all with concrete, pavement, dirt, lawns, houses, buildings, etc. As for using Pontchartrain - if it needs dredging - agreed, but no need to destroy a natural ecosystem unnecessarily - the Mississippi already artificially manipulated - hence my thinking to use it.
-- trekbody, Sep 13 2005



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