There are certainly lower and higher parts of N.O. but I remember standing on a terrace of a building by the river where I could seen over the levee. It was clear that the river level was above the level of the streets. A levee breach there would be catastrophic.

Of course the city began on the natural levees but there was not enough room there for the population that collected around the major port it became. The major building of levees along the lower Mississippi was triggered, if my recollection of history is correct, after the disastrous flood of 1927. When faced with an invasion, people tend to build a high wall. It is not always the best choice.

You are probably correct, Baton Rouge may well become the next major port on the Gulf. As sea level rises and the SE LA parishes become completely submerged there will be no alternative. N.O. will probably be just a legend by the 22nd century.

US-made goods have nothing to do with why New Orleans is where it is. French trade, on the other hand …

Right, the French were a bit more realistic when they settled the city …

Yes it does. It is surrounded by levees about as high as they can be built. Inside, much of it is lower than mean sea level and normal Mississippi River level. When it is destroyed either by flooding from torrential rains (Katrina), the sea via Lake Pontchartrain (Katrina), or from the river (the levees there were nearly overtopped in the 1970s), it will have to be rebuilt.

In hindsight, levees were a bad choice for the long term, When floods were prevented from spreading out into the city, some of the sediment was deposited in the channel bottom itself, thus raising normal river level. The levees were raised and the same thing happened and so the present situation evolved. In addition to that, New Orleans is sinking along with much of the Gulf Coast and, of course, sea level is rising by thermal expansion and addition of meltwater.

New Orleans is worth seeing — a lot of people love it — but I’d suggest not putting off a visit too very long. .

I guess I wasn’t clear. I presumed no such thing. What I did presume was that the buyers did not have enough education to even know to look for indications of mass movement — or know what to look for.

In the U. S., geological concepts and information are taught in elementary school, in some high schools, and is an elective in college for everyone but geo majors. So many adults have an essentially pre-19th century outlook when it comes to evaluating hazards such as weathering, erosion, flooding, earthquakes, volcanism. Some, of course, develop some practical knowledge from bitter experience. In our states’ rightsy country not all states have any useful requirements related to siting of buildings etc. to avoid the most likely geohazards. Maybe it’s different in the UK.

Cheaper and it gets the right thing (reduction of CO2) done. It also prevents leaks. No pipeline, no leaks.