Why not jack up New Orleans?

[Loopydude]

@Duckster

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.

I’ve read all about this, but on the subject of that bedrock…

I thought it was pure bollocks when I was told, but somebody at work just claimed part of the reason NO is sinking is because they’re pumping oil out from underneath it. “Cite??” quoth I, and so didst he reply: “I heard it on the radio.”

[Robot_Arm]

@Dewey Finn

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?

It would be expensive, to be sure, but it would almost be worth it just for the name, New New Orleans.

How the locals would pronounce that, I have no idea.

[Loopydude]

They could assume the proper La Nouvelle-Orléans.

[Valgard]

@MaryEFoo

[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]

Sounds like hydraulic fill, that’s how places like Treasure Island naval base in the SF Bay were created. It doesn’t do well in earthquakes.

And before someone asks, one of the big seismic worry zones is smack dab in the middle of the country, the New Madrid fault near St. Louis, MO. The last time it let go was a series of four enormous earthquakes in 1811-1812, about the same magnitude as the 1906 SF quake and felt throughout half the country. Little seismic resistance in the midwest so when that fault goes again it could be a pretty mind-blowing catastrophe.

[StarvingButStrong]

A radical suggestion, but who says we need a New Orleans? Or even a New New Orleans?

People move around all the time in America, chasing opportunities and fleeing lack of same. So this would be just a more concentrated and one-way flow of population.

Okay, maybe the refineries or pumping stations or whatever need to stay there at the mouth of the Mississippi, but why can’t the population be allowed to disperse? They can move to other states, other towns in the same state, whatever they please. Louisiana could plan out and build several smaller towns ON DECENTLY SOLID GROUND nearby for the people who need to live within commuting distance of the oil refineries, etc. Then just let natural population growth/industrial growth create a new city out of one or more of the towns – or not – as events unfold over time.

Let “New Orleans” turn into a legend. “When I was your age, I once visited…”