13 ms·

As the article rightly points out, levees will do nothing for a slow moving hurricane like Harvey that dumps tons of rain or for a large cat5 hurricane with sto

by ahnick 5y ago

As the article rightly points out, levees will do nothing for a slow moving hurricane like Harvey that dumps tons of rain or for a large cat5 hurricane with storm level surges that are much higher than Ida. The place is sinking while sea level rise is already locked in with current levels of CO2 in the atmosphere. The only solution is relocation, but nobody wants to hear that. It is an inevitability that New Orleans will be uninhabitable. The only question is when.

candiddevmike 5y ago
This is my fear as well. All of these coastal cities are at risk for relocation, who's footing the bill for the government to buy the houses, relocate the people, provide them new houses, jobs, etc? There is a ton of self interest in keeping people in places like New Orleans (and even growing the population), but we need to accept the reality that these places will be uninhabitable in the near future. I already foresee a bunch of folks getting tons of money for Hurricane Ida claims only to rebuild houses in the same exact spot. We should encourage them to take the money and move away, not stick around.
- bostonsre 5y ago
  I can't imagine flood insurance is very cheap in these locations and I don't think this is an imminent domain type situation where the government would buy houses. At some point, people will be ruined financially and won't be able to rebuild. Other wealthier places may be able to use municipal bonds to fight sea level rise. In the valley in Foster City, the choice was between pricey flood insurance and a cheaper municipal bond to construct a robust levee and the latter was chosen. The city is small enough and the residents were wealthy enough to do it. I'm kind of curious if anyone will attempt to damn up or construct locks under the golden gate bridge. I think the valley could be wealthy enough to do it.
  - beerandt 5y ago
    The federal government actually does have block grant programs to buy out homeowners, or will pay to raise their house, if the cost is cheaper than building a levee or similar flood protection.
    - bostonsre 5y ago
      Interesting.. That kind of sounds like it would be impossibly expensive for the government as the sea level rises.
      - beerandt 5y ago
        Depends- at some point it usually becomes cheaper to provide flood protection, if enough houses are close to one another. Plus those grants are kinda complex to navigate, and you can't do it as an individual. It has to be part of a local communities overall flood mitigation / risk-reduction plan.
- Animats 5y ago
  It's mostly river deltas that have this problem. A small sea level rise reduces flow at the river outlet, causing flooding out of proportion to the sea level rise. The only big river delta in the US is the Mississippi. East Asia has far worse problems. Most of China's port cities are on river deltas. Tapei is on a river delta. Ho Chi Min City is on a river delta. Singapore is on a river delta. These are all areas where the land to water slope is very low. The western US is mountainous enough that there's more than enough land rise to prevent flooding more than a short distance inland. Even in places that look flat, like LA near Venice, go three blocks inland and you're tens of feet higher. Places that built on fill, such as San Francisco and Foster City, do exist, but are small enough for barriers and not fed by upstream rivers.
  - Clewza313 5y ago
    Singapore is a small island, and the mighty Singapore River, located on that island, is all of 3 km long.
    - blahedo 5y ago
      But it sits in the delta of a river that is, if not mighty, at least bigger than 3km. The real question is, is the island flat enough to trigger the river-delta problems the gp post indicates.
      - Clewza313 5y ago
        I remain genuinely confused about what river you are referring to here. The Johor River?
- treeman79 5y ago
  Government doesn’t need to do a thing. Assuming flood insurance prices are realistic (not propped up by government), eventually no new construction will happen because no one will approve/afford insurance. Existing places will get cheaper / hell hole as rates keep going up. Federal flood insurance has distorted market prices drastically in many places
- MisterBastahrd 5y ago
  New Orleans and Port Fourchon are pretty vital to US economic interests because of their ports.
selimthegrim 5y ago
The article fails to point out that New Orleans' drainage system is actually better than Houston's.
- dangerbird2 5y ago
  Moving ungodly volumes of rainwater away from homes and out of the streets is one of the few things New Orleans' infrastructure does really well. I remember times when I'd be walking down the sidewalk through knee-deep water to get to class, and on my way back 45 minutes later it's basically all gone. A Harvey-level rainstorm would certainly cause damage, but NOLA would probably handle it better than any major city in the country.
  - malkuth23 5y ago
    Our pumps are so old many are still using wooden screws and run on 25 cycle power. Think how much water we could pull out if the system was upgraded? New Orleans is more prepared to survive than any other city with a few hundred miles of it, including mega cities like Houston.
    - selimthegrim 5y ago
      As was clarified upthread, Wood pumps are not wooden pumps.
      - dangerbird2 5y ago
        Also, there were new pumping stations built after Katrina.
- MisterBastahrd 5y ago
  Vastly better than Houston's. Not even remotely comparable. The same rainfall amount that would put Houston under water would have a few streets and underpasses rendered impassible for a few hours in New Orleans and the surrounding areas. My hometown was on the east side near the eyewall when the storm stalled over them for a few hours. Tons of wind damage, virtually zero flooding aside from parking lots and one levee that was damaged from the storm surge.
nickthemagicman 5y ago
Nola has the most shipping tonnage of any port in the hemisphere. There's many billions of dollars of port and plant infrastructure there. Its way cheaper and easier just to rebuild the city every few years and pay to buffer it against disaster than to relocate all of that. Just like it's easier to keep a legacy code base that's working and making money than fully rebuild it. Nola's not going anywhere anytime soon.
- justinator 5y ago
  You're right! There's too much money invested - and to be made! People will just have to suffer. Let's keep our focus on what's important.
  - nickthemagicman 5y ago
    I think most people there would rather the rich chaos of New Orleans than the cultural blandness of the rest of the country. "America has only three cities: New York, San Francisco, and New Orleans. Everywhere else is Cleveland" - Tennessee Williams Am currently evacuated from Ida, and drove all the way to Kentucky from Nola and from what I'm seeing so far, can confirm that quote is depressingly accurate. Why does the rest of the country look like one giant strip mall from coast to coast? What happened to America?
    - justinator 5y ago
      Yeah, that was sarcasm. Also eat orphans.
      - nickthemagicman 5y ago
        In New Orleans they would throw anything in a frier. Have a fried Orphan and catfish basket.
    - selimthegrim 5y ago
      Am in DC, but I toast you with an imaginary glass of Early Times.
SmellTheGlove 5y ago
How does New Orleans compare to the Netherlands in terms of long term flood risk?
mcast 5y ago
People said the same cynical comments about not being able to build skyscrapers alongside the coast of New York City, which would be impossible to excavate deep underground without flooding the city. We should look into improving the infrastructure and innovating our urban planning layouts to better handle these natural disasters rather than just abandoning them. Yes, hurricanes will continue to strengthen, but improving building codes and adding more canals and waterways for flood control can mitigate many of the deadly problems. For what it's worth, New Orleans is a historic city with a rich culture.
- kibwen 5y ago
  > For what it's worth, New Orleans is a historic city with a rich culture. Nobody wants to lose New Orleans. It's a great city. But the problem is accurately summed up by the OP: "How much can places where millions of people live be fortified? At what cost? And who pays for it?" The only good news is that the Port of South Louisiana is the biggest and arguably most important port in the Western Hemisphere (and that's without even taking into account the Port of New Orleans or the Port of Baton Rouge, both in the top 10). There is enormous nationwide economic and geopolitical incentive to protect the city. The bad news is that New Orleans would be sinking even without rising sea levels.
  - mdorazio 5y ago
    Not sure where you’re getting your port numbers from, but you must be referring to something non-standard. Neither of those are top 10 and definitely not even remotely as important as the west coast ports or NJ. See [1]. [1] https://www.logisticsmgmt.com/article/top_30_u.s._ports_big_ports_got_bigger_in_2020 https://www.logisticsmgmt.com/article/top_30_u.s._ports_big_...
    - selimthegrim 5y ago
      These are for containers, New Orleans/BR/S LA is also big in bulk grain, oil and gas, etc, and as for breakbulk see https://www.freightwaves.com/news/port-of-new-orleans-sees-22-bump-in-breakbulk-cargo https://www.freightwaves.com/news/port-of-new-orleans-sees-2...
Spooky23 5y ago
In some ways, levees make it worse by damaging the delta, which ultimately protects the city.
- MisterBastahrd 5y ago
  Nope. Different levee system. The system that harms the delta is the one that keeps the Mississippi from cutting a path wherever it wants. This other one is a system that simply protects populations from storm surge.
Muromec 5y ago
>The place is sinking while sea level rise is already locked in with current levels of CO2 in the atmosphere. Biggest airport in The Netherlands is 3 meters below the sea level, but at least we don't have hurricanes here, just North Sea https://en.wikipedia.org/wiki/Amsterdam_Airport_Schiphol https://en.wikipedia.org/wiki/Amsterdam_Airport_Schiphol
- kibwen 5y ago
  Europe is generally protected from hurricanes due to how far north everything is, but as the north Atlantic warms tropical storms will become more frequent, potentially graduating into legitimate hurricanes every once in a while.
reddog 5y ago
>New Orleans will be uninhabitable. The only question is when. A very, very long time from now. According to the IPCC Sixth Assessment Report sea levels are projected to rise between .57 and 1.25 meters by 2120. So unless you have waves currently lapping against your back porch you, your kids, your grandkids and your great-grandkids will be OK in NO. For context, sea levels have risen about .3 meters over the last hundred years and we have adapted without city evacuation and relocation. https://sealevel.nasa.gov/ipcc-ar6-sea-level-projection-tool https://sealevel.nasa.gov/ipcc-ar6-sea-level-projection-tool
- ahnick 5y ago
  The midway point in the sea level tool you linked is actually 1.41m by 2100. That's 4.6 feet of sea level rise by the end of the century and this is based on our current models where we are continuously discovering more and more positive feedback mechanisms that is accelerating sea level rise. (https://www.science.org/news/2020/11/seas-are-rising-faster-ever https://www.science.org/news/2020/11/seas-are-rising-faster-...) Now those levee walls that were originally 13 feet high are now less than 9 feet from the water and no longer really capable of doing the job they were designed for. So we better build bigger walls to keep all the water out, so let's go back and spend billions and billions more to have bigger walls, which by the way encourages more and more people to move into flood prone areas. Then you really set things up for a black swan event where something unexpected causes a levee failure (b/c that's never happened before) and then a bunch of people die. So maybe you and your kids MIGHT be okay, but your grandkids and your great-grandkids? probably not.
  - reddog 5y ago
    >The midway point in the sea level tool you linked is actually 1.41m by 2100. No. Not sure where 1.41m is coming from. Take a closer look at the linked NASA site. You will need to click on the link labled "View global projection" (sorry, there isn't a direct link). You will see a graph labeled "Projected Sea-Level Rise Under Different SSP Scenarios". The midpoint highest rise of all seven of the scenarios for 2100 is just .88 meters and that's for the most pessimistic SSP5-8.5 Low Confidence scenario. The more likely scenarios are about 1-2 feet. Your great-grandkids will be fine.
beerandt 5y ago
This is alarmist BS. I worked on the surveys and cors equipment that directly measures subsidence in Louisiana, and have worked on many of the levees and other coastal civil works. Relocation? For a problem that hasn't happened yet and isn't likely to happen in the foreseeable future is absurd. New York City is at a much greater risk and will be inundated long before New Orleans. The fastest rate of subsidence in New Orleans is/was due to organics in the soil decomposing once the groundwater table was lowered (drainage projects going back 300 yrs), allowing oxygen to infiltrate. This decomposition is mostly complete in most areas of the city. Piles under everything from skyscrapers to personal homes penetrates the organic layers, so buildings don't subside even if the ground does. The biggest risk to the city and state is environmental activists, the EPA & the Army Corps of Engineers, and the largely untouchable Mississippi River levee system, preventing the delta land building process that counteracts subsidence by depositing new sediment in yearly floods. Additionally, erosion/ runoff prevention and dams through out the Mississippi, Missouri, and Ohio river watersheds have decreased the amount of sediment flowing down river, and results in less sediment available for natural land building. The coastal barrier marshes and islands are dying because we've stopped the natural processes that sustain them. Each mile of marsh results in the natural lowering of storm surge by 1/2' to 2'. The federal government, environmental groups and others fight the restoration of these natural processes. For example, they argue fresh water introduction will hurt dolphin populations in coastal bays, but they are only capable of being there in the first place because of man made interference: the bays were freshwater until the levees cut off their natural supply of freshwater. As for global warming? Infrastructure, business and homes are amortized at 30yrs or less. Maybe up to 50yrs for very large civil projects. Worst case sea level rise estimates easily gives New Orleans 300+ more yrs, likely much longer, a time frame longer than the current age of the city.
- pfisch 5y ago
  It is and it isn't. His scenario won't happen but what will happen is fairly similar. No one is going to make large capital investments in a city that gets blown away all the time. Every time New Orleans takes a big hit like this people leave, and less money is put back into the city. The population of New Orleans was higher in 1980 than it is now. I am from New Orleans, and since Katrina the infrastructure has been getting worse, not better. There probably isn't going to be some big dramatic event that kills New Orleans. It will just keep shrinking and pulling in towards the French Quarter as it gets hit repeatedly by extreme weather events. It will just become smaller and more impoverished over time until it is maybe abandoned at some distant point in the future. It will be a death by inches.
malkuth23 5y ago
That might be the only solution you can think of, but that does not make it the only possibility. What you are really saying is you don't think New Orleans is worth saving. New Orleans infrastructure consists of far more than just levees. Our pumping system is currently rated to remove 1 inch of rain the first hour and 1/2 inch each additional hour. We can remove this much rain with wooden screw pumps that still run on 25 cycle power. Upgrading or adding to the pumps in New Orleans to handle more water makes far more sense than giving up on what I believe is the most special city in America. https://www.atlasobscura.com/articles/new-orleans-wood-screw-pumps-history-power-drainage-flooding-infrastructure https://www.atlasobscura.com/articles/new-orleans-wood-screw... You say that nobody want to hear your hot take on abandoning New Orleans, a city with one of the most important ports in the country, yet I hear this proposed constantly (and upvoted) by people that have almost no specialized knowledge of infrastructure. It is armchair nihilism and imo not helpful at all. The army corps of engineers thinks differently. Agencies like the CPRA are working to restore land on the coast. There are ways to mitigate the damage, to reduce the risk and protect the city. Yes it is expensive. No it is not cheaper than losing our ports, our people, our culture. https://gnoinc.org/news/ports-of-south-louisiana-new-orleans-plaquemines-ranked-1-4-11-in-america/ https://gnoinc.org/news/ports-of-south-louisiana-new-orleans... Soon enough, if we don't invest in NOLA, you will likely be right, but I doubt it will be because there was no other option. It will be because we as a country made a huge mistake and failed to act. The truth is, a lot of America does not care about people or cities in the south. New Orleans gets a bit more attention because tourists had a good time on Bourbon once, but overall it is treated as an oddity and not an essential piece of the both the economic and cultural fabric of America. There are people down here that feel the same way about California with its earthquakes and wild fires and I make similar arguments when arguing with them. Speaking of which, NYC fared far worse against the remnants of a storm we took head on. Should we abandon it or improve it? Hell no we should not give up on NYC, nor SF with it's earthquakes, or LA with it's water shortages, or Baltimore with its crime, or Detroit with its collapse of industry and definitely not New Orleans.
- ahnick 5y ago
  It's not the only solution I can think of, but it's the only practical one. Sure you could build giant sea walls around the area or bring in land and start literally raising all the buildings above sea level (similar to what Chicago did in the mid 1800s), but you are talking billions of dollars, maybe hundreds of billions. Once you get into that situation it just makes sense to move everything upstream and perhaps only fortify key infrastructure like ports until even those pieces have to be relocated. The army corps of engineers is not given the option of not trying to save New Orleans. People in government tell them to go build levees and protect the city from flooding and they do the best job that they can, but they are fighting a losing war. The time to introduce relocation assistance programs is now, so you spread the cost and process out over many years; otherwise, you are going to just end up doing the same thing later, but it will cost more money and more lives will have been lost.
jazzyjackson 5y ago
Well going by Hurricane Ida, New Jersey will have to relocate themselves before New Orleans, but not before they build a seawall under the Verrazzano bridge. To describe the destruction of a city as "inevitable" is just admitting you don't want to spend the billions of dollars necessary to protect it.
sjs382 5y ago
> levees will do nothing for [...] a large cat5 hurricane with storm level surges that are much higher than Ida Of course they will. Over-topping of a levee is a MUCH LESS SEVERE outcome than a levee breach.

by ahnick 5y ago

candiddevmike 5y ago

This is my fear as well. All of these coastal cities are at risk for relocation, who's footing the bill for the government to buy the houses, relocate the people, provide them new houses, jobs, etc? There is a ton of self interest in keeping people in places like New Orleans (and even growing the population), but we need to accept the reality that these places will be uninhabitable in the near future. I already foresee a bunch of folks getting tons of money for Hurricane Ida claims only to rebuild houses in the same exact spot. We should encourage them to take the money and move away, not stick around.

bostonsre 5y ago
I can't imagine flood insurance is very cheap in these locations and I don't think this is an imminent domain type situation where the government would buy houses. At some point, people will be ruined financially and won't be able to rebuild. Other wealthier places may be able to use municipal bonds to fight sea level rise. In the valley in Foster City, the choice was between pricey flood insurance and a cheaper municipal bond to construct a robust levee and the latter was chosen. The city is small enough and the residents were wealthy enough to do it. I'm kind of curious if anyone will attempt to damn up or construct locks under the golden gate bridge. I think the valley could be wealthy enough to do it.
- beerandt 5y ago
  The federal government actually does have block grant programs to buy out homeowners, or will pay to raise their house, if the cost is cheaper than building a levee or similar flood protection.
  - bostonsre 5y ago
    Interesting.. That kind of sounds like it would be impossibly expensive for the government as the sea level rises.
    - beerandt 5y ago
      Depends- at some point it usually becomes cheaper to provide flood protection, if enough houses are close to one another. Plus those grants are kinda complex to navigate, and you can't do it as an individual. It has to be part of a local communities overall flood mitigation / risk-reduction plan.
Animats 5y ago
It's mostly river deltas that have this problem. A small sea level rise reduces flow at the river outlet, causing flooding out of proportion to the sea level rise. The only big river delta in the US is the Mississippi. East Asia has far worse problems. Most of China's port cities are on river deltas. Tapei is on a river delta. Ho Chi Min City is on a river delta. Singapore is on a river delta. These are all areas where the land to water slope is very low. The western US is mountainous enough that there's more than enough land rise to prevent flooding more than a short distance inland. Even in places that look flat, like LA near Venice, go three blocks inland and you're tens of feet higher. Places that built on fill, such as San Francisco and Foster City, do exist, but are small enough for barriers and not fed by upstream rivers.
- Clewza313 5y ago
  Singapore is a small island, and the mighty Singapore River, located on that island, is all of 3 km long.
  - blahedo 5y ago
    But it sits in the delta of a river that is, if not mighty, at least bigger than 3km. The real question is, is the island flat enough to trigger the river-delta problems the gp post indicates.
    - Clewza313 5y ago
      I remain genuinely confused about what river you are referring to here. The Johor River?
treeman79 5y ago
Government doesn’t need to do a thing. Assuming flood insurance prices are realistic (not propped up by government), eventually no new construction will happen because no one will approve/afford insurance. Existing places will get cheaper / hell hole as rates keep going up. Federal flood insurance has distorted market prices drastically in many places
MisterBastahrd 5y ago
New Orleans and Port Fourchon are pretty vital to US economic interests because of their ports.

selimthegrim 5y ago

The article fails to point out that New Orleans' drainage system is actually better than Houston's.

dangerbird2 5y ago
Moving ungodly volumes of rainwater away from homes and out of the streets is one of the few things New Orleans' infrastructure does really well. I remember times when I'd be walking down the sidewalk through knee-deep water to get to class, and on my way back 45 minutes later it's basically all gone. A Harvey-level rainstorm would certainly cause damage, but NOLA would probably handle it better than any major city in the country.
- malkuth23 5y ago
  Our pumps are so old many are still using wooden screws and run on 25 cycle power. Think how much water we could pull out if the system was upgraded? New Orleans is more prepared to survive than any other city with a few hundred miles of it, including mega cities like Houston.
  - selimthegrim 5y ago
    As was clarified upthread, Wood pumps are not wooden pumps.
    - dangerbird2 5y ago
      Also, there were new pumping stations built after Katrina.
MisterBastahrd 5y ago
Vastly better than Houston's. Not even remotely comparable. The same rainfall amount that would put Houston under water would have a few streets and underpasses rendered impassible for a few hours in New Orleans and the surrounding areas. My hometown was on the east side near the eyewall when the storm stalled over them for a few hours. Tons of wind damage, virtually zero flooding aside from parking lots and one levee that was damaged from the storm surge.

nickthemagicman 5y ago

Nola has the most shipping tonnage of any port in the hemisphere. There's many billions of dollars of port and plant infrastructure there. Its way cheaper and easier just to rebuild the city every few years and pay to buffer it against disaster than to relocate all of that. Just like it's easier to keep a legacy code base that's working and making money than fully rebuild it. Nola's not going anywhere anytime soon.

justinator 5y ago
You're right! There's too much money invested - and to be made! People will just have to suffer. Let's keep our focus on what's important.
- nickthemagicman 5y ago
  I think most people there would rather the rich chaos of New Orleans than the cultural blandness of the rest of the country. "America has only three cities: New York, San Francisco, and New Orleans. Everywhere else is Cleveland" - Tennessee Williams Am currently evacuated from Ida, and drove all the way to Kentucky from Nola and from what I'm seeing so far, can confirm that quote is depressingly accurate. Why does the rest of the country look like one giant strip mall from coast to coast? What happened to America?
  - justinator 5y ago
    Yeah, that was sarcasm. Also eat orphans.
    - nickthemagicman 5y ago
      In New Orleans they would throw anything in a frier. Have a fried Orphan and catfish basket.
  - selimthegrim 5y ago
    Am in DC, but I toast you with an imaginary glass of Early Times.

SmellTheGlove 5y ago

How does New Orleans compare to the Netherlands in terms of long term flood risk?

mcast 5y ago

People said the same cynical comments about not being able to build skyscrapers alongside the coast of New York City, which would be impossible to excavate deep underground without flooding the city. We should look into improving the infrastructure and innovating our urban planning layouts to better handle these natural disasters rather than just abandoning them. Yes, hurricanes will continue to strengthen, but improving building codes and adding more canals and waterways for flood control can mitigate many of the deadly problems. For what it's worth, New Orleans is a historic city with a rich culture.

kibwen 5y ago
> For what it's worth, New Orleans is a historic city with a rich culture. Nobody wants to lose New Orleans. It's a great city. But the problem is accurately summed up by the OP: "How much can places where millions of people live be fortified? At what cost? And who pays for it?" The only good news is that the Port of South Louisiana is the biggest and arguably most important port in the Western Hemisphere (and that's without even taking into account the Port of New Orleans or the Port of Baton Rouge, both in the top 10). There is enormous nationwide economic and geopolitical incentive to protect the city. The bad news is that New Orleans would be sinking even without rising sea levels.
- mdorazio 5y ago
  Not sure where you’re getting your port numbers from, but you must be referring to something non-standard. Neither of those are top 10 and definitely not even remotely as important as the west coast ports or NJ. See [1]. [1] https://www.logisticsmgmt.com/article/top_30_u.s._ports_big_ports_got_bigger_in_2020 https://www.logisticsmgmt.com/article/top_30_u.s._ports_big_...
  - selimthegrim 5y ago
    These are for containers, New Orleans/BR/S LA is also big in bulk grain, oil and gas, etc, and as for breakbulk see https://www.freightwaves.com/news/port-of-new-orleans-sees-22-bump-in-breakbulk-cargo https://www.freightwaves.com/news/port-of-new-orleans-sees-2...

Spooky23 5y ago

In some ways, levees make it worse by damaging the delta, which ultimately protects the city.

MisterBastahrd 5y ago
Nope. Different levee system. The system that harms the delta is the one that keeps the Mississippi from cutting a path wherever it wants. This other one is a system that simply protects populations from storm surge.

Muromec 5y ago

>The place is sinking while sea level rise is already locked in with current levels of CO2 in the atmosphere. Biggest airport in The Netherlands is 3 meters below the sea level, but at least we don't have hurricanes here, just North Sea https://en.wikipedia.org/wiki/Amsterdam_Airport_Schiphol https://en.wikipedia.org/wiki/Amsterdam_Airport_Schiphol

kibwen 5y ago
Europe is generally protected from hurricanes due to how far north everything is, but as the north Atlantic warms tropical storms will become more frequent, potentially graduating into legitimate hurricanes every once in a while.

reddog 5y ago

>New Orleans will be uninhabitable. The only question is when. A very, very long time from now. According to the IPCC Sixth Assessment Report sea levels are projected to rise between .57 and 1.25 meters by 2120. So unless you have waves currently lapping against your back porch you, your kids, your grandkids and your great-grandkids will be OK in NO. For context, sea levels have risen about .3 meters over the last hundred years and we have adapted without city evacuation and relocation. https://sealevel.nasa.gov/ipcc-ar6-sea-level-projection-tool https://sealevel.nasa.gov/ipcc-ar6-sea-level-projection-tool

ahnick 5y ago
The midway point in the sea level tool you linked is actually 1.41m by 2100. That's 4.6 feet of sea level rise by the end of the century and this is based on our current models where we are continuously discovering more and more positive feedback mechanisms that is accelerating sea level rise. (https://www.science.org/news/2020/11/seas-are-rising-faster-ever https://www.science.org/news/2020/11/seas-are-rising-faster-...) Now those levee walls that were originally 13 feet high are now less than 9 feet from the water and no longer really capable of doing the job they were designed for. So we better build bigger walls to keep all the water out, so let's go back and spend billions and billions more to have bigger walls, which by the way encourages more and more people to move into flood prone areas. Then you really set things up for a black swan event where something unexpected causes a levee failure (b/c that's never happened before) and then a bunch of people die. So maybe you and your kids MIGHT be okay, but your grandkids and your great-grandkids? probably not.
- reddog 5y ago
  >The midway point in the sea level tool you linked is actually 1.41m by 2100. No. Not sure where 1.41m is coming from. Take a closer look at the linked NASA site. You will need to click on the link labled "View global projection" (sorry, there isn't a direct link). You will see a graph labeled "Projected Sea-Level Rise Under Different SSP Scenarios". The midpoint highest rise of all seven of the scenarios for 2100 is just .88 meters and that's for the most pessimistic SSP5-8.5 Low Confidence scenario. The more likely scenarios are about 1-2 feet. Your great-grandkids will be fine.

beerandt 5y ago

This is alarmist BS. I worked on the surveys and cors equipment that directly measures subsidence in Louisiana, and have worked on many of the levees and other coastal civil works. Relocation? For a problem that hasn't happened yet and isn't likely to happen in the foreseeable future is absurd. New York City is at a much greater risk and will be inundated long before New Orleans. The fastest rate of subsidence in New Orleans is/was due to organics in the soil decomposing once the groundwater table was lowered (drainage projects going back 300 yrs), allowing oxygen to infiltrate. This decomposition is mostly complete in most areas of the city. Piles under everything from skyscrapers to personal homes penetrates the organic layers, so buildings don't subside even if the ground does. The biggest risk to the city and state is environmental activists, the EPA & the Army Corps of Engineers, and the largely untouchable Mississippi River levee system, preventing the delta land building process that counteracts subsidence by depositing new sediment in yearly floods. Additionally, erosion/ runoff prevention and dams through out the Mississippi, Missouri, and Ohio river watersheds have decreased the amount of sediment flowing down river, and results in less sediment available for natural land building. The coastal barrier marshes and islands are dying because we've stopped the natural processes that sustain them. Each mile of marsh results in the natural lowering of storm surge by 1/2' to 2'. The federal government, environmental groups and others fight the restoration of these natural processes. For example, they argue fresh water introduction will hurt dolphin populations in coastal bays, but they are only capable of being there in the first place because of man made interference: the bays were freshwater until the levees cut off their natural supply of freshwater. As for global warming? Infrastructure, business and homes are amortized at 30yrs or less. Maybe up to 50yrs for very large civil projects. Worst case sea level rise estimates easily gives New Orleans 300+ more yrs, likely much longer, a time frame longer than the current age of the city.

pfisch 5y ago
It is and it isn't. His scenario won't happen but what will happen is fairly similar. No one is going to make large capital investments in a city that gets blown away all the time. Every time New Orleans takes a big hit like this people leave, and less money is put back into the city. The population of New Orleans was higher in 1980 than it is now. I am from New Orleans, and since Katrina the infrastructure has been getting worse, not better. There probably isn't going to be some big dramatic event that kills New Orleans. It will just keep shrinking and pulling in towards the French Quarter as it gets hit repeatedly by extreme weather events. It will just become smaller and more impoverished over time until it is maybe abandoned at some distant point in the future. It will be a death by inches.

malkuth23 5y ago

That might be the only solution you can think of, but that does not make it the only possibility. What you are really saying is you don't think New Orleans is worth saving. New Orleans infrastructure consists of far more than just levees. Our pumping system is currently rated to remove 1 inch of rain the first hour and 1/2 inch each additional hour. We can remove this much rain with wooden screw pumps that still run on 25 cycle power. Upgrading or adding to the pumps in New Orleans to handle more water makes far more sense than giving up on what I believe is the most special city in America. https://www.atlasobscura.com/articles/new-orleans-wood-screw-pumps-history-power-drainage-flooding-infrastructure https://www.atlasobscura.com/articles/new-orleans-wood-screw... You say that nobody want to hear your hot take on abandoning New Orleans, a city with one of the most important ports in the country, yet I hear this proposed constantly (and upvoted) by people that have almost no specialized knowledge of infrastructure. It is armchair nihilism and imo not helpful at all. The army corps of engineers thinks differently. Agencies like the CPRA are working to restore land on the coast. There are ways to mitigate the damage, to reduce the risk and protect the city. Yes it is expensive. No it is not cheaper than losing our ports, our people, our culture. https://gnoinc.org/news/ports-of-south-louisiana-new-orleans-plaquemines-ranked-1-4-11-in-america/ https://gnoinc.org/news/ports-of-south-louisiana-new-orleans... Soon enough, if we don't invest in NOLA, you will likely be right, but I doubt it will be because there was no other option. It will be because we as a country made a huge mistake and failed to act. The truth is, a lot of America does not care about people or cities in the south. New Orleans gets a bit more attention because tourists had a good time on Bourbon once, but overall it is treated as an oddity and not an essential piece of the both the economic and cultural fabric of America. There are people down here that feel the same way about California with its earthquakes and wild fires and I make similar arguments when arguing with them. Speaking of which, NYC fared far worse against the remnants of a storm we took head on. Should we abandon it or improve it? Hell no we should not give up on NYC, nor SF with it's earthquakes, or LA with it's water shortages, or Baltimore with its crime, or Detroit with its collapse of industry and definitely not New Orleans.

ahnick 5y ago
It's not the only solution I can think of, but it's the only practical one. Sure you could build giant sea walls around the area or bring in land and start literally raising all the buildings above sea level (similar to what Chicago did in the mid 1800s), but you are talking billions of dollars, maybe hundreds of billions. Once you get into that situation it just makes sense to move everything upstream and perhaps only fortify key infrastructure like ports until even those pieces have to be relocated. The army corps of engineers is not given the option of not trying to save New Orleans. People in government tell them to go build levees and protect the city from flooding and they do the best job that they can, but they are fighting a losing war. The time to introduce relocation assistance programs is now, so you spread the cost and process out over many years; otherwise, you are going to just end up doing the same thing later, but it will cost more money and more lives will have been lost.

jazzyjackson 5y ago

Well going by Hurricane Ida, New Jersey will have to relocate themselves before New Orleans, but not before they build a seawall under the Verrazzano bridge. To describe the destruction of a city as "inevitable" is just admitting you don't want to spend the billions of dollars necessary to protect it.

sjs382 5y ago

> levees will do nothing for [...] a large cat5 hurricane with storm level surges that are much higher than Ida Of course they will. Over-topping of a levee is a MUCH LESS SEVERE outcome than a levee breach.