New Orleans levees passed their first major test(nationalgeographic.com)
nationalgeographic.com
New Orleans levees passed their first major test
https://www.nationalgeographic.com/environment/article/new-orleans-levees-passed-their-first-major-test
142 comments
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.
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.
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.
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.
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.
Cities across the country will die much sooner from economic and political reasons than New Orleans will die from subsidence. (Although New Orleans is likely included in that first set as well, based on current leadership.)
But we don't discourage economic development in those places. My amortization comment was perhaps not explicit enough, but as long as people think the city will last beyond amortization periods, future abandonment/inundation/end-of-days predictions are not a rational reason to preclude investment.
Most businesses shoot for a payback period of 10 years or less.
I expect you're right about slow death, but it won't be for climatic or geologic or hydraulic reasons.
Fear of those reasons might contribute, but then we've gone full circle back to "alarmist BS".
But we don't discourage economic development in those places. My amortization comment was perhaps not explicit enough, but as long as people think the city will last beyond amortization periods, future abandonment/inundation/end-of-days predictions are not a rational reason to preclude investment.
Most businesses shoot for a payback period of 10 years or less.
I expect you're right about slow death, but it won't be for climatic or geologic or hydraulic reasons.
Fear of those reasons might contribute, but then we've gone full circle back to "alarmist BS".
You're being unrealistic about the reality of living in New Orleans and the level of capital investment in New Orleans vs Baton Rouge or other cities that aren't under constant threat of destruction.
People just aren't going to come in and build nice shopping centers in New Orleans. It isn't happening and hasn't happened. Why would it when they could build in another city where it won't get destroyed and it will be more profitable?
It is extremely stressful every year watching hurricanes and wondering if your house is going to be destroyed. Then when your house is destroyed it is no fun at all to be involved in gutting it and rebuilding it. On top of that no one is making investments in the city so it hardly has any good jobs.
It isn't alarmist to recognize what is already happening. The climate is creating more extreme weather events that are undermining New Orleans. It doesn't need to be some fake "The Day After Tomorrow" style disaster that people can easily recognize. It is an insidious, slow, hollowing out of the city.
How many water boil warnings have their been since Katrina? How often has electricity been inconsistent in the city? I can tell you it happens a lot more now than it did before Katrina, and it is going to be even worse after Ida.
People just aren't going to come in and build nice shopping centers in New Orleans. It isn't happening and hasn't happened. Why would it when they could build in another city where it won't get destroyed and it will be more profitable?
It is extremely stressful every year watching hurricanes and wondering if your house is going to be destroyed. Then when your house is destroyed it is no fun at all to be involved in gutting it and rebuilding it. On top of that no one is making investments in the city so it hardly has any good jobs.
It isn't alarmist to recognize what is already happening. The climate is creating more extreme weather events that are undermining New Orleans. It doesn't need to be some fake "The Day After Tomorrow" style disaster that people can easily recognize. It is an insidious, slow, hollowing out of the city.
How many water boil warnings have their been since Katrina? How often has electricity been inconsistent in the city? I can tell you it happens a lot more now than it did before Katrina, and it is going to be even worse after Ida.
Climate isn't the problem with any of those issues, politics is.
It's not fear of flooding that prevents anyone from investing in, eg New Orleans East. It's two decades of zero policing.
And there's a reason Entergy continues to operate as a completely separate corporate entity in the city, and it's not because "used to be nopsi".
The water guys can't even operate a billing system, let alone engineer the distribution network. They ran through probably a dozen companies post- Katrina just to do an assessment and map and maintenance plans, and they all quit for having to deal with the city.
That's why they can't keep the water on. But an unnecessary new airport? They had no problem throwing a billion dollars at contractors for that.
If people were afraid of sea level rising, they wouldn't just be moving into another swamp/marsh outside of city limits or across the lake. People don't want to live at sea level without a levee on the North Shore, they just don't want to live in New Orleans, despite the +20ft msl and up levees.
It's not fear of flooding that prevents anyone from investing in, eg New Orleans East. It's two decades of zero policing.
And there's a reason Entergy continues to operate as a completely separate corporate entity in the city, and it's not because "used to be nopsi".
The water guys can't even operate a billing system, let alone engineer the distribution network. They ran through probably a dozen companies post- Katrina just to do an assessment and map and maintenance plans, and they all quit for having to deal with the city.
That's why they can't keep the water on. But an unnecessary new airport? They had no problem throwing a billion dollars at contractors for that.
If people were afraid of sea level rising, they wouldn't just be moving into another swamp/marsh outside of city limits or across the lake. People don't want to live at sea level without a levee on the North Shore, they just don't want to live in New Orleans, despite the +20ft msl and up levees.
>And there's a reason Entergy continues to operate as a completely separate corporate entity in the city, and it's not because "used to be nopsi".
Because the City Council-as-regulator can be astroturfed and snowed easily by false promises about "black-start" capability for power plants and work on distribution systems?
Because the City Council-as-regulator can be astroturfed and snowed easily by false promises about "black-start" capability for power plants and work on distribution systems?
I don't think that's the counter point you think it is.
The fact that Entergy has to do so much to convince the city to allow a power plant to be built, should be all the proof you need, as far as why no one wants to invest in the city.
And that black start capability proved it's worth this week.
The fact that Entergy has to do so much to convince the city to allow a power plant to be built, should be all the proof you need, as far as why no one wants to invest in the city.
And that black start capability proved it's worth this week.
What kind of "islanded" black start is this where they have to hook up an external transmission line? That isn’t what they told city council. They could have had solar and batteries, even MISO knew this.
It was an option presented to the politicians and they rejected it in favor of starting in sync with the grid.
If they would have done a black start, rejoining the grid would have apparently been more complicated.
But the bigger point is: why does the city fight local investment and improvement of infrastructure? As if the city is doing everyone a favor that wants to build something.
That's what's killing the city, not fear of flooding.
If they would have done a black start, rejoining the grid would have apparently been more complicated.
But the bigger point is: why does the city fight local investment and improvement of infrastructure? As if the city is doing everyone a favor that wants to build something.
That's what's killing the city, not fear of flooding.
The city doesn't want some capital investment that Entergy execs can soak the ratepayers on, sell bonds (which will be underwater when people shift to solar+batteries), and bounce with their bonus package instead of actually shelling out for operating expenses. When I went before the council I made sure Giarrusso read this report UMN [1] generated about the entire MISO system, about the payoff on a gas plant vs solar+batteries, and they went ahead and voted for the plant anyway.
[1] https://energytransition.umn.edu/modernizing-minnesotas-grid...
[1] https://energytransition.umn.edu/modernizing-minnesotas-grid...
People are perfectly happy to come and drop hundreds of millions on developing apartment complexes in the CBD for some reason, so why not shopping centers? The good jobs bit I agree with, I am about to leave Tulane with a PhD and barring some remote offers from Houston I can't find a means, motive or opportunity to stay here as much as I enjoy it.
>People are perfectly happy to come and drop hundreds of millions on developing apartment complexes in the CBD for some reason
The amount of real estate investment in New Orleans is incredibly low compared to other cities. They build more buildings in Atlanta in one year than they have in the last 30 years in New Orleans.
The amount of real estate investment in New Orleans is incredibly low compared to other cities. They build more buildings in Atlanta in one year than they have in the last 30 years in New Orleans.
Still gonna argue that's more politics than fear of flooding.
How many homes were destroyed and will need to be rebuilt due to ida?
Probably high 5 figures to mid 6 figures, depending on what you count as rebuilding. Lots of houses with no roof, or with trees through them that could go either way re teardown or repair.
I don't think anyone knows just yet. It took 4 days just to do the preliminary power outage assessment.
I don't think anyone knows just yet. It took 4 days just to do the preliminary power outage assessment.
That seems hard to believe, tbh, but now I'm really bothered that I don't have any definitive source.
But "high 5 figures" would be >50k. According to this: https://www.usatoday.com/story/news/nation/2021/09/05/hurric... they are looking at 22k power poles.
Were homes twice as likely to be destroyed than power poles were to be damaged?
But "high 5 figures" would be >50k. According to this: https://www.usatoday.com/story/news/nation/2021/09/05/hurric... they are looking at 22k power poles.
Were homes twice as likely to be destroyed than power poles were to be damaged?
Here's Entergy's visual: worse than the next 4 hurricanes on the list, combined, including Katrina. (This is part of what I meant when I said msm isn't covering it well up thread.)
https://www.entergy.com/hurricaneida/damage/
And Entergy only covers a portion of the area, but includes all of New Orleans and most of Baton Rouge.
There are a lot more trees than power poles to fall. Lots of trees fell through houses, which allowed additional water and damage, and they won't know anything until insurance and possibly an engineer or contractor look at it.
FEMA just started blue roof on Tuesday I think.
But definitely over 50k damaged, if not destroyed. Just depends on where you draw the line.
https://www.entergy.com/hurricaneida/damage/
And Entergy only covers a portion of the area, but includes all of New Orleans and most of Baton Rouge.
There are a lot more trees than power poles to fall. Lots of trees fell through houses, which allowed additional water and damage, and they won't know anything until insurance and possibly an engineer or contractor look at it.
FEMA just started blue roof on Tuesday I think.
But definitely over 50k damaged, if not destroyed. Just depends on where you draw the line.
A large amount of the marsh reduction is due to oil company activities. You're not wrong that we need to let the river shift, but that alone isn't going to save the coastline, and it's not the primary cause of the loss of the marshlands. Also, it should be noted that the largest lobby group against fresh water induction isn't environmental groups, but the commercial fishing industry. The second largest lobbying group against it is the recreational fishing community. Both of these groups have the support of environmental groups because fresh water induction would indeed kill a large percentage of anything living in that induction area, and those living things are part of the ecosystem that keeps the marshlands alive.
I don't think OP is wrong in that a Harvey situation would be disastrous. A decent percentage of the pumps in the city are broken for most of the year, and without those pumps, a storm like Harvey would likely result in levels of flooding similar to the levees breaking.
I don't think OP is wrong in that a Harvey situation would be disastrous. A decent percentage of the pumps in the city are broken for most of the year, and without those pumps, a storm like Harvey would likely result in levels of flooding similar to the levees breaking.
Oil companies are responsible for the canals, but that only allowed salt water to intrude quicker after rain or floods. But it doesn't change the overall regime of becoming salt dominant. It just means maybe 40 freshwater days a year instead of 50 at s given location, but it doesn't change what's growing there.
Additionally, marsh biological productivity has been directly tied to shoreline length. So a marsh with proper salinity levels and more shoreline will actually create more food, for more wildlife.
I do believe that they ought to be held to the terms of their permits, which is typically to backfill anything not actively maintained or abandoned. And to prevent erosion beyond the limits of the permits. But it doesn't seem that's part of the negotiation.
>fresh water induction would indeed kill a large percentage of anything living in that induction area,
False- the locations already getting freshwater (not sediment) diversions and the natural breaks in the levees are the only healthy parts of the marsh right now. Go look at them on Google Earth. Mardi gras pass and the other natural breaks are the only places naturally building land outside of the Atchafalaya Delta.
For the new sediment diversions: It's not going to kill anything-it's just going to push the brackish water out and the salt water further, for a limited number of weeks per year. The wildlife will move with it, as it always has.
The commercial guys don't want to burn more gas to get to saltwater, and the oyster guys (the real money and lobby power) don't want conditions to change at their existing water bottom leases.
>and those living things are part of the ecosystem that keeps the marshlands alive.
No freshwater mixing with saltwater is the basis for the entire estuary systems. Without that, the photosynthesis doesn't happen in the freshwater flora, and the food chain starts there for the rest of the living things.
>A decent percentage of the pumps in the city are broken for most of the year,
Political problem with the city, not an environmental or engineering problem.
Additionally, marsh biological productivity has been directly tied to shoreline length. So a marsh with proper salinity levels and more shoreline will actually create more food, for more wildlife.
I do believe that they ought to be held to the terms of their permits, which is typically to backfill anything not actively maintained or abandoned. And to prevent erosion beyond the limits of the permits. But it doesn't seem that's part of the negotiation.
>fresh water induction would indeed kill a large percentage of anything living in that induction area,
False- the locations already getting freshwater (not sediment) diversions and the natural breaks in the levees are the only healthy parts of the marsh right now. Go look at them on Google Earth. Mardi gras pass and the other natural breaks are the only places naturally building land outside of the Atchafalaya Delta.
For the new sediment diversions: It's not going to kill anything-it's just going to push the brackish water out and the salt water further, for a limited number of weeks per year. The wildlife will move with it, as it always has.
The commercial guys don't want to burn more gas to get to saltwater, and the oyster guys (the real money and lobby power) don't want conditions to change at their existing water bottom leases.
>and those living things are part of the ecosystem that keeps the marshlands alive.
No freshwater mixing with saltwater is the basis for the entire estuary systems. Without that, the photosynthesis doesn't happen in the freshwater flora, and the food chain starts there for the rest of the living things.
>A decent percentage of the pumps in the city are broken for most of the year,
Political problem with the city, not an environmental or engineering problem.
Honestly, that is a great a reply.
I especially agree that some dams on the Mississippi need to destroyed and have agriculture be moved away from the river, as the dead zone in Gulf of Mexico is caused by upstream agriculture states.
I especially agree that some dams on the Mississippi need to destroyed and have agriculture be moved away from the river, as the dead zone in Gulf of Mexico is caused by upstream agriculture states.
Hey thanks for a very interesting and thought provoking reply. I lived in NOLA for 10 years and long may it live! Spot on with the destruction of the marshlands - something so desperately needing reversal.
I was just wondering if you could provide a citation for this:
>>>Worst case sea level rise estimates easily gives New Orleans 300+ more yrs
I hope so. I fear not.
Talking to my friends in the city it feels like if ida had spooled up 1 day further out, it would have wiped the place off the map. I know it isn’t true, but man, the wetlands are so mostly water below town, the storm didn’t loose strength, the next time… etc. I hope ida was the second-order wake up call the city needed to survive a future cat 5 with 30+ foot storm surge.
I was just wondering if you could provide a citation for this:
>>>Worst case sea level rise estimates easily gives New Orleans 300+ more yrs
I hope so. I fear not.
Talking to my friends in the city it feels like if ida had spooled up 1 day further out, it would have wiped the place off the map. I know it isn’t true, but man, the wetlands are so mostly water below town, the storm didn’t loose strength, the next time… etc. I hope ida was the second-order wake up call the city needed to survive a future cat 5 with 30+ foot storm surge.
The LA CPRA coastal master plan, combined with army corps of engineers studies on further improving the post-Katrina levees.
I'm trying to find the levee recommendations, but Biden's takeover seems to have broken all my bookmarks in the ACOE website.
Basically it's just the ipcc/ epa most-likely-worse case scenario with some local adjustments, combined with CPRA's master plan for surge reduction and (non-nola) coastal protection and barrier island rebuilding, combined with the Corps' recommended levee improvements.
You end up with lessened storm surges and raised levees that can match sea-level rise to whatever hight is feasible for the look levees, and back-out the years from the projected rate of sea level rise.
And if they do the wall across the Orleans land bridge (preventing storm surge at the Rigolets and chef's pass), it's actually a much higher number. But that plan is on the back burner for now.
I'm trying to find the levee recommendations, but Biden's takeover seems to have broken all my bookmarks in the ACOE website.
Basically it's just the ipcc/ epa most-likely-worse case scenario with some local adjustments, combined with CPRA's master plan for surge reduction and (non-nola) coastal protection and barrier island rebuilding, combined with the Corps' recommended levee improvements.
You end up with lessened storm surges and raised levees that can match sea-level rise to whatever hight is feasible for the look levees, and back-out the years from the projected rate of sea level rise.
And if they do the wall across the Orleans land bridge (preventing storm surge at the Rigolets and chef's pass), it's actually a much higher number. But that plan is on the back burner for now.
Thanks for all the context!
> As for global warming? Infrastructure, business and homes are amortized at 30yrs or less. Maybe up to 50yrs for very large civil projects.
I don’t understand this comment. I assume you’re not talking about financial amortization. Do you mean the climate impact of new construction (such as 1 ton CO2 per 1 ton concrete) has some kind of sunset period?
I don’t understand this comment. I assume you’re not talking about financial amortization. Do you mean the climate impact of new construction (such as 1 ton CO2 per 1 ton concrete) has some kind of sunset period?
We did also cut the intracoastal waterway through swamps/marshes for commercial purposes (including large scale cypress logging).
It's real easy to see on google earth all the nice straight lines we cut all over the place.
That must have an impact on saltwater intrusion and help facilitate coastal wetland loss.
That must have an impact on saltwater intrusion and help facilitate coastal wetland loss.
> 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.
Your argument depends on this but you give neither numbers nor citations, so it's unsubstantiated and we have no idea how true it is. Numbers I've seen, that are bad, but not worst case are 6' by the end of the century and 20'-60' over longer timescales. I seriously doubt New Orleans will be just fine through that. Many coastal cities will have to move. It's not practical to wall in all of the coast to that extent. Many cities would end up being islands.
Your argument depends on this but you give neither numbers nor citations, so it's unsubstantiated and we have no idea how true it is. Numbers I've seen, that are bad, but not worst case are 6' by the end of the century and 20'-60' over longer timescales. I seriously doubt New Orleans will be just fine through that. Many coastal cities will have to move. It's not practical to wall in all of the coast to that extent. Many cities would end up being islands.
> Your argument depends on this but you give neither numbers nor citations, so it's unsubstantiated and we have no idea how true it is.
Unsubstantiated on this thread. I mean, you can look it up and find out if it's true yourself. It's also weird that you follow it up with numbers of your own, but also no references, so you must think that's alright to do.
Unsubstantiated on this thread. I mean, you can look it up and find out if it's true yourself. It's also weird that you follow it up with numbers of your own, but also no references, so you must think that's alright to do.
You also don't know how substantiated my claims are, but at least with numbers you could look it up. Parent provided only an argument from authority. There is no easy way to falsify it. You'd have to do all the research from scratch.
People don't seem to understand what I'm saying. If the OP at least gives numbers you can compare them to easily looked up estimates and find out if they're reasonable or if you can ignore him in a couple minutes.
Without that I'd have to search projected sea level rise, then read all about the elevation, vulnerability to storm surge, levees, flood risks, etc for New Orleans. It would take hours to know if the OP has a valid point or not. You might have to do that anyway, but at least if his numbers are bad you can shortcut the process and ignore him.
Without that I'd have to search projected sea level rise, then read all about the elevation, vulnerability to storm surge, levees, flood risks, etc for New Orleans. It would take hours to know if the OP has a valid point or not. You might have to do that anyway, but at least if his numbers are bad you can shortcut the process and ignore him.
How is sediment deposition supposed to counteract the subsidence of land that has anything built on it?
Outside of levee protections, structures are all on piles above the flood elevation, so floods literally go under the house.
Inside levee protections, as the system currently exists, it doesn't, so houses have to have sand pumped under them occasionally to fill gaps left by subsidence.
The house is on piles, so it remains in place.
Inside levee protections, as the system currently exists, it doesn't, so houses have to have sand pumped under them occasionally to fill gaps left by subsidence.
The house is on piles, so it remains in place.
>Piles under everything from skyscrapers to personal homes penetrates the organic layers, so buildings don't subside even if the ground does.
The sinking building in SF would like to differ with this. If a building is not built correctly, all bets are off.
The sinking building in SF would like to differ with this. If a building is not built correctly, all bets are off.
The problem in San Francisco is entirely different. It's on poorly designed building. Even if every building in San Francisco had that problem, it still wouldn't be relevant.
The problem strata in New Orleans is the top 10-20' of soil. Mostly whatever's above the pumped-down, controlled, water table.
Piles only need to go that deep to suffice, or more typically until they hit the first layer of sand, which is stable. Literally every slab house built in New Orleans is built in these, because before this, everything was on blocks so it could constantly be raised and leveled.
The problem strata in New Orleans is the top 10-20' of soil. Mostly whatever's above the pumped-down, controlled, water table.
Piles only need to go that deep to suffice, or more typically until they hit the first layer of sand, which is stable. Literally every slab house built in New Orleans is built in these, because before this, everything was on blocks so it could constantly be raised and leveled.
>or more typically until they hit the first layer of sand, which is stable.
I think this is the first time I have ever seen someone claim that a layer of sand is stable. But hey, NOLA is one of the craziest places, so sure, sand is stable there.
I think this is the first time I have ever seen someone claim that a layer of sand is stable. But hey, NOLA is one of the craziest places, so sure, sand is stable there.
We're not talking about a beach here.
Sand underground with overburden pressure is quite stable, to the point that piles driven to it are treated as bearing piles (supported primarily on the end/tip), not friction piles (supported on sides by friction).
It's non-cohesive, so doesn't shrink or swell, and once it's compacted/consolidated, it's fixed volume and quite stable.
Sand underground with overburden pressure is quite stable, to the point that piles driven to it are treated as bearing piles (supported primarily on the end/tip), not friction piles (supported on sides by friction).
It's non-cohesive, so doesn't shrink or swell, and once it's compacted/consolidated, it's fixed volume and quite stable.
Does having poor soil mean New Orleans buildings are designed better? Or does New Orleans suffer from both bad soil and designs?
It just means everything gets built on piles, so there's a lot of local experience.
I wouldn't say better, because there are/were multiple skyscrapers with chunks of facade falling off them. At least a couple are abandoned because they were built so bad.
But they're not sinking.
I wouldn't say better, because there are/were multiple skyscrapers with chunks of facade falling off them. At least a couple are abandoned because they were built so bad.
But they're not sinking.
Yes, AFAIK the piles didn't go all the way down to solid bedrock and San Francisco is basically built on a garbage dump covered over from previous devastating earth quakes, basically. They were improperly installed and if they had been the building would likely be fine. So, you're both right.
That area of the city is built on infill, but that is by no means true of most of the city’s area.
300+ years? And the biggest risk to the city is environmental activists and the EPA? You must be joking.
The biggest risk is the fact that according to our best estimates by 2050 sea level rise will be another 1.5 feet in that area. (https://sealevel.nasa.gov/ipcc-ar6-sea-level-projection-tool) For an area that is already on average 7 feet below sea level. New Orleans topography is basically a bowl between Lake Pontchartrain and the Gulf of Mexico. Couple that with stronger and more frequent hurricanes and there will be few places left to live in New Orleans and the surrounding area.
People who give other people a false sense of hope is what endangers lives and sets up future generations for devastation. If you really want to help people you need to break the cycle and subsidize relocation costs for those who currently live there that can't afford to move. All these mitigation efforts like restoring the natural coastal barriers may delay some flooding (so sure do it), but it will not prevent the inevitable and it is coming much sooner than 300+ years.
The biggest risk is the fact that according to our best estimates by 2050 sea level rise will be another 1.5 feet in that area. (https://sealevel.nasa.gov/ipcc-ar6-sea-level-projection-tool) For an area that is already on average 7 feet below sea level. New Orleans topography is basically a bowl between Lake Pontchartrain and the Gulf of Mexico. Couple that with stronger and more frequent hurricanes and there will be few places left to live in New Orleans and the surrounding area.
People who give other people a false sense of hope is what endangers lives and sets up future generations for devastation. If you really want to help people you need to break the cycle and subsidize relocation costs for those who currently live there that can't afford to move. All these mitigation efforts like restoring the natural coastal barriers may delay some flooding (so sure do it), but it will not prevent the inevitable and it is coming much sooner than 300+ years.
>For an area that is already on average 7 feet below sea level.
There are areas as low as -22' msl. Maybe -25'.
But that's irrelevant, because the edge of the bowl and protection is at a minimum elevation ~+20' msl and up, depending on adjustments for things like modeled wave height.
Whereas New York's highest protection is currently something like +8', and isn't a closed loop.
And what's the elevation of the deepest basement/ subway/ tunnel in NYC? Because I bet it's a lot lower than -22' or -25' msl.
There are areas as low as -22' msl. Maybe -25'.
But that's irrelevant, because the edge of the bowl and protection is at a minimum elevation ~+20' msl and up, depending on adjustments for things like modeled wave height.
Whereas New York's highest protection is currently something like +8', and isn't a closed loop.
And what's the elevation of the deepest basement/ subway/ tunnel in NYC? Because I bet it's a lot lower than -22' or -25' msl.
I don’t think NYC is really a counterexample/gotcha to their argument. If the commenter is right that a 1.5ft rise in sea level will cause a lot of damage to New Orleans, surely that line of thinking applies to both places (and all places close to the sea).
>a 1.5ft rise in sea level
It won't, precisely because New Orleans already has many places below sea level. It's got a head start.
It's spent billions of dollars over 100+ years making the outer boundaries water tight, and building the infrastructure to support all of that, including the ability to pump 100% of rainfall out.
To New Orleans, the cost of any sea level rise has essentially already approached the marginal rate.
No where else in the world, with the exception of probably the Netherlands, is better prepared for rising waters, whether it's storm surge or sea level rise.
Everywhere else has to pretty much start from scratch.
It won't, precisely because New Orleans already has many places below sea level. It's got a head start.
It's spent billions of dollars over 100+ years making the outer boundaries water tight, and building the infrastructure to support all of that, including the ability to pump 100% of rainfall out.
To New Orleans, the cost of any sea level rise has essentially already approached the marginal rate.
No where else in the world, with the exception of probably the Netherlands, is better prepared for rising waters, whether it's storm surge or sea level rise.
Everywhere else has to pretty much start from scratch.
... katrina happened though, within the past 100+ years. either they didnt make them water tight, or they planned for situations that arent reality.
It was mostly geotech failures related to the organic material mentioned above, combined with a patchwork system at that point in time.
The post-Katrina improvements have combined the patchwork systems into one.
The improvements should have been made long before Katrina, but the corps of engineers stalled most attempts, and Congress refused to let the corps do anything without direct Congressional funding, which never came. Until Katrina.
The post-Katrina improvements have combined the patchwork systems into one.
The improvements should have been made long before Katrina, but the corps of engineers stalled most attempts, and Congress refused to let the corps do anything without direct Congressional funding, which never came. Until Katrina.
And I only use New York City as an example, because of the argument about spending money on investments and infrastructure near sea level.
People aren't currently avoiding New York because of sea level rise. And are spending far greater amounts on business investments there.
People aren't currently avoiding New York because of sea level rise. And are spending far greater amounts on business investments there.
If the city survives at 7 feet below sea level, I don't understand what's stopping it from surviving at 8.5 feet.
The buildings aren't getting any taller, in case of an intrusion.
The levees can be raised.
And the buildings are on piles already. Relatively simple to raise, if needed, compared to what other coastal cities will have to do.
With extra stress on the word relatively.
And the buildings are on piles already. Relatively simple to raise, if needed, compared to what other coastal cities will have to do.
With extra stress on the word relatively.
>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
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
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-...) 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.
So maybe you and your kids MIGHT be okay, but your grandkids and your great-grandkids? probably not.
>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.
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.
1.41m by 2100 is the projection for “Grand Isle”, the closest location in the model to New Orleans. Sea level and sea level rise is not uniform worldwide, so local predictions are very important. This is also true for temperature and other climate change impacts, and is one of the biggest improvements in the latest IPCC report.
It looks like all model scenarios agree fairly well out to 2100 both in the global projections and in projections for Grand Isle. Thus, I’d wager good money that New Orleans will see 1-2m sea level rise by 2100 regardless of any climate mitigations we perform.
It looks like all model scenarios agree fairly well out to 2100 both in the global projections and in projections for Grand Isle. Thus, I’d wager good money that New Orleans will see 1-2m sea level rise by 2100 regardless of any climate mitigations we perform.
Grand Isle (which Ida did a number on) is well south of NOLA in Jefferson Parish, and not part of the metro area. It exists for fishing and tourism.
What was the IPCC's expected sea level rise in that time though? 3mm?
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...
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...
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.
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...
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.
>We can remove this much rain with wooden screw pumps that still run on 25 cycle power.
To clarify, those are metal pumps invented by a man named Albert Baldwin Wood, not pumps literally made out of wood.
To clarify, those are metal pumps invented by a man named Albert Baldwin Wood, not pumps literally made out of wood.
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.
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.
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.
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.
I mean, the food isn't _that_ much worse in Morgan City long term.
I bet there's amazing food there.
They just don't have the Alcoholism.
Also, if the Old River control system ever fails Morgan City will be the next New Orleans.
https://en.m.wikipedia.org/wiki/Old_River_Control_Structure
They just don't have the Alcoholism.
Also, if the Old River control system ever fails Morgan City will be the next New Orleans.
https://en.m.wikipedia.org/wiki/Old_River_Control_Structure
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.
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?
"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?
Am in DC, but I toast you with an imaginary glass of Early Times.
Cheers to you too!
Glad we're safe, the levies held, and the city appears to be coming back faster than expected.
Glad we're safe, the levies held, and the city appears to be coming back faster than expected.
Yeah, that was sarcasm. Also eat orphans.
In New Orleans they would throw anything in a frier.
Have a fried Orphan and catfish basket.
Have a fried Orphan and catfish basket.
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.
The article fails to point out that New Orleans' drainage system is actually better than Houston's.
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.
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.
As was clarified upthread, Wood pumps are not wooden pumps.
Also, there were new pumping stations built after Katrina.
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.
Do you think the surge in your hometown was high enough the old levees wouldn't have handled it?
Those are the old levees. They didn't even approve the new levee system for that area until this year.
I live in Houston and can attest to that being ridiculously true. This is completely due to government incompetence (mostly local, not state or federal). The lack of remediation after Harvey is just sad. So many missed opportunities. Bill White was the last major who did anything about it, and he took a long term view that his successors have basically ignored.
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.
> 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.
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.
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_...
[1] https://www.logisticsmgmt.com/article/top_30_u.s._ports_big_...
Your source is container only.
2 South Louisiana, LA, Port of 238.0
3 New York, NY and NJ 136.6
4 Corpus Christi, TX 111.2
5 Beaumont, TX 101.1
6 New Orleans, LA 92.
7 Long Beach, CA 80.7
8 Baton Rouge, LA 73.4
9 Los Angeles, CA 63.0
10 Virginia, VA, Port of 61.7
11 Lake Charles, LA 58.0
13 Mobile, AL 56.9
14 Plaquemines, LA, Port of 52.8
15 Baltimore, MD 44.2
16 Savannah, GA 41.9
17 Texas City, TX 41.3
18 Huntington - Tristate 36.8
https://www.bts.gov/content/tonnage-top-50-us-water-ports-ra...
Total Tonnage US:2 South Louisiana, LA, Port of 238.0
3 New York, NY and NJ 136.6
4 Corpus Christi, TX 111.2
5 Beaumont, TX 101.1
6 New Orleans, LA 92.
7 Long Beach, CA 80.7
8 Baton Rouge, LA 73.4
9 Los Angeles, CA 63.0
10 Virginia, VA, Port of 61.7
11 Lake Charles, LA 58.0
13 Mobile, AL 56.9
14 Plaquemines, LA, Port of 52.8
15 Baltimore, MD 44.2
16 Savannah, GA 41.9
17 Texas City, TX 41.3
18 Huntington - Tristate 36.8
https://www.bts.gov/content/tonnage-top-50-us-water-ports-ra...
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-2...
Looking at it again the source that I was citing is from 2004, which predates Katrina. Looks like it still hasn't bounced back in terms of tonnage passing through the port. But in terms of importance New Orleans isn't diminished; a deepwater port at the mouth of what is by far the country's most significant watershed is always going to be a strategic lynchpin. The entire midwest would be diminished without New Orleans.
>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
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
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.
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.
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.
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.
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.
Singapore is a small island, and the mighty Singapore River, located on that island, is all of 3 km long.
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.
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.
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.
Interesting.. That kind of sounds like it would be impossibly expensive for the government as the sea level rises.
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.
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.
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
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
New Orleans and Port Fourchon are pretty vital to US economic interests because of their ports.
How does New Orleans compare to the Netherlands in terms of long term flood risk?
> 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.
Of course they will. Over-topping of a levee is a MUCH LESS SEVERE outcome than a levee breach.
In some ways, levees make it worse by damaging the delta, which ultimately protects the city.
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.
> Army Corps of Engineers, which rebuilt the system
It's funny they don't mention the companies like Arcadis that actually designed the barrier, because they have the know-how from managing the Dutch flood barriers
https://www.h2owaternetwerk.nl/h2o-actueel/beschermingssyste...
It's funny they don't mention the companies like Arcadis that actually designed the barrier, because they have the know-how from managing the Dutch flood barriers
https://www.h2owaternetwerk.nl/h2o-actueel/beschermingssyste...
There is plenty of good news from Louisiana. But mostly because of the levees holding, the loss of life was low.
Evacuations from outlying areas also helped tremendously. Those were hammered.
I’m not sure they were really tested what with the track to the west.
In the northern hemisphere, the worst quarter of a cyclonic storm is to the NW. That's where winds blow in toward, driving storm surge, and it's where the warm tropical moisture tends to meet cooler northern continental airmasses, triggering rain (cold air can hold less total moisture than warm). Storms tracking east of New Orleans produce less overall damage as the primary storm surge is directed further east, and the city itself is subjected to the less-damaging, and already somewhat moisture-depleted NE and NW winds as the storm passes.
Ida tracked just west of downtown New Orleans. The eyewall didn't interact with downtown proper, though it did cross the Mississippi a few miles NW of New Orleans. Storm surge was significant, though because Ida was a smaller (though intense) storm, total surge was less than for Katrina, 16 years earlier (14 ft vs. ~20). Katrina's peak surge was far closer to Lake Ponchartrain, whilst Ida's was further to the SW, being highest near Grand Isle.
https://www.weather.gov/mob/katrina
https://www.weather.gov/mob/ida
Ida tracked just west of downtown New Orleans. The eyewall didn't interact with downtown proper, though it did cross the Mississippi a few miles NW of New Orleans. Storm surge was significant, though because Ida was a smaller (though intense) storm, total surge was less than for Katrina, 16 years earlier (14 ft vs. ~20). Katrina's peak surge was far closer to Lake Ponchartrain, whilst Ida's was further to the SW, being highest near Grand Isle.
https://www.weather.gov/mob/katrina
https://www.weather.gov/mob/ida
Correction: the worst quarter is the northeast.
North West? Like Portland and Seattle?
No.
I'm not referring to portions of the US, but to segments of any given storm.
Given counterclockwise rotation in of these storms in the northern hemisphere, and a westward track of tropical storms (see for example the 2020 North Atlantic Hurricane storm tracks: https://en.wikipedia.org/wiki/2020_Atlantic_hurricane_season...):
- Hurricanes will make landfall from the east or south.
- Winds will tend to approach landfall from the east or south.
- Most intense rain activity tends to be to the NE of the storm. (I'd miswritten this as NW above. I've corrected that in a follow-up self-reply.)
Because of the westward storm track, hurricane landfalls on the West coast are exceedingly rare. They occasionally happen on the Pacific coast of Mexico or Baja California (about 19 or 20 storms between 1950 and 2000). By the time storms reach the latitude of Los Angeles they're subtropical.
https://en.wikipedia.org/wiki/List_of_Baja_California_Penins...
Most Eastern-Pacific hurricanes (that is, off the west coast of Mexico or the US) drift westward into the Pacific. Some strike Hawaii.
I'm not referring to portions of the US, but to segments of any given storm.
Given counterclockwise rotation in of these storms in the northern hemisphere, and a westward track of tropical storms (see for example the 2020 North Atlantic Hurricane storm tracks: https://en.wikipedia.org/wiki/2020_Atlantic_hurricane_season...):
- Hurricanes will make landfall from the east or south.
- Winds will tend to approach landfall from the east or south.
- Most intense rain activity tends to be to the NE of the storm. (I'd miswritten this as NW above. I've corrected that in a follow-up self-reply.)
Because of the westward storm track, hurricane landfalls on the West coast are exceedingly rare. They occasionally happen on the Pacific coast of Mexico or Baja California (about 19 or 20 storms between 1950 and 2000). By the time storms reach the latitude of Los Angeles they're subtropical.
https://en.wikipedia.org/wiki/List_of_Baja_California_Penins...
Most Eastern-Pacific hurricanes (that is, off the west coast of Mexico or the US) drift westward into the Pacific. Some strike Hawaii.
Somewhat incredibly, Ida killed far more people as a weakened tropical storm in the northeast after crossing the entire US than it did as a Cat4/5 hurricane on the gulf coast.
From Wikipedia:
> As of September 4, a total of 70 deaths have been confirmed in relation to Ida: 27 in New Jersey, 18 in New York, 13 in Louisiana, 5 in Pennsylvania, 2 in Mississippi, 2 in Alabama, 1 in Maryland, 1 in Virginia, and 1 in Connecticut.
From Wikipedia:
> As of September 4, a total of 70 deaths have been confirmed in relation to Ida: 27 in New Jersey, 18 in New York, 13 in Louisiana, 5 in Pennsylvania, 2 in Mississippi, 2 in Alabama, 1 in Maryland, 1 in Virginia, and 1 in Connecticut.
I'm in NYC. Besides walking my dog briefly in the heavy rain twice I wasn't even aware of Ida until the clear morning after someone showed me flooded subway photos looking like from the end of MGS2. I'm not sure it was communicated properly save for the flash flooding broadcast that could have also come from just a lesser heavy thunderstorm.
From what I read, that was the very first time the NWS had every issued a Flash Flood warning for NYC. Seems like that might have earned it a little more attention.
This reminds me of the people complaining about how destructive the floods in Houston were after Harvey. Nevermind that the forecasts for days leading up to it were 40" of rain. What part of 40" of rain sounds like no big deal?
This reminds me of the people complaining about how destructive the floods in Houston were after Harvey. Nevermind that the forecasts for days leading up to it were 40" of rain. What part of 40" of rain sounds like no big deal?
People in NYC get so many “severe” weather warnings for random parts of the metro area far from where they live that they just tune them out.
My reaction when I got the Ida updates was “yeah, I get it, it’s raining”. I left my house as normal and thought nothing of it. It was by pure luck that I didn’t take the subway anywhere because I’d almost certainly have been stuck when the rain went insane about an hour later.
I’ll definitely scrutinize the warnings more carefully in the future, but I totally understand why a lot of people ignored them and then were surprised by how bad the storm was.
My reaction when I got the Ida updates was “yeah, I get it, it’s raining”. I left my house as normal and thought nothing of it. It was by pure luck that I didn’t take the subway anywhere because I’d almost certainly have been stuck when the rain went insane about an hour later.
I’ll definitely scrutinize the warnings more carefully in the future, but I totally understand why a lot of people ignored them and then were surprised by how bad the storm was.
If you've never had to deal with it, you don't comprehend the danger.
I know workers that moved to New Orleans after Katrina to do the actual post storm cleanup, first hand, and didn't evacuate for Ida, knowing it was a more powerful storm.
Some of them had their entire roof(s) blown off and had 100' pine trees fall through their house while they were home, riding it out.
Even seeing the post storm damage doesn't convey the actual danger during these weather events.
I know workers that moved to New Orleans after Katrina to do the actual post storm cleanup, first hand, and didn't evacuate for Ida, knowing it was a more powerful storm.
Some of them had their entire roof(s) blown off and had 100' pine trees fall through their house while they were home, riding it out.
Even seeing the post storm damage doesn't convey the actual danger during these weather events.
>"If you've never had to deal with it, you don't comprehend the danger."
I don't believe you need to experience something first hand in order to comprehend the danger. I've never visited an active conflict zone but I fully comprehend the danger of traveling to one for a holiday. Conversely I have friends in New Orleans who didn't evacuate for Katrina who also didn't evacuate for Ida. They obviously comprehended the danger very well. There will always be people who are stubborn, careless or possibly just have a much higher risk profile regardless of their personal history.
It's also odd to think that people wouldn't understand the danger of flash floods given that in the last 5 weeks alone we have seen the flash floods in Henan Province China as well as the flash flooding in Eastern Germany. These two flash flood events were major international news stories and you would be hard pressed to not have seen those images.
I don't believe you need to experience something first hand in order to comprehend the danger. I've never visited an active conflict zone but I fully comprehend the danger of traveling to one for a holiday. Conversely I have friends in New Orleans who didn't evacuate for Katrina who also didn't evacuate for Ida. They obviously comprehended the danger very well. There will always be people who are stubborn, careless or possibly just have a much higher risk profile regardless of their personal history.
It's also odd to think that people wouldn't understand the danger of flash floods given that in the last 5 weeks alone we have seen the flash floods in Henan Province China as well as the flash flooding in Eastern Germany. These two flash flood events were major international news stories and you would be hard pressed to not have seen those images.
I think you mean Western Germany, assuming you’re talking about the floods that happened in July. Or were there more recent ones in the East too?
> I've never visited an active conflict zone but I fully comprehend the danger of traveling to one for a holiday.
Do you, really? Without even knowing which conflict zone, or doing any research? All areas of violence have had and will have a similar danger level?
Do you, really? Without even knowing which conflict zone, or doing any research? All areas of violence have had and will have a similar danger level?
>"Do you, really? Without even knowing which conflict zone, or doing any research?"
Where did that even come from? I neither stated or even implied any of that. I haven't visited an active conflict zone precisely because I did research. It's somewhat bizarre you would make those assumptions when you know nothing about me.
Where did that even come from? I neither stated or even implied any of that. I haven't visited an active conflict zone precisely because I did research. It's somewhat bizarre you would make those assumptions when you know nothing about me.
>"I'm not sure it was communicated properly save for the flash flooding broadcast that could have also come from just a lesser heavy thunderstorm."
The National Weather Service Service issued it's first ever "flash flood emergency" for NYC on Wednesday.[1] It's not like these are common for the region.
Alerts went out to cell phones in NJ and NY at 8:41PM EDT with 3 more alerts following. Why would it matter whether a flash flood emergency accompanies a heavy thunderstorm vs tropical storm? It's still the same potentially life-threatening and catastrophic event.
[1] https://twitter.com/NWSNewYorkNY/status/1433277322048663554/...
The National Weather Service Service issued it's first ever "flash flood emergency" for NYC on Wednesday.[1] It's not like these are common for the region.
Alerts went out to cell phones in NJ and NY at 8:41PM EDT with 3 more alerts following. Why would it matter whether a flash flood emergency accompanies a heavy thunderstorm vs tropical storm? It's still the same potentially life-threatening and catastrophic event.
[1] https://twitter.com/NWSNewYorkNY/status/1433277322048663554/...
It's never clear to me what to do with a flash flood warning.
Do I stay indoors? Do I move to higher ground?
It can be a little vague as far as what should I do given my exact location.
I guess it's up to each individual to research those things beforehand...
Do I stay indoors? Do I move to higher ground?
It can be a little vague as far as what should I do given my exact location.
I guess it's up to each individual to research those things beforehand...
I believe the warning alerts advise not to travel unless fleeing flooding and the flash flood emergency alerts specifically state "move immediately to higher ground" and "don't walk or drive through flood areas."
One criticism I've read a few times in the past week has been suggesting that people may have had alert fatigue. While it is true that things like the Weather Channel have contributed a lot of noise(naming winter storms for instance.) Additionally there were 4 separate alerts that went out the night of the flooding. And of course things like Amber alerts and similar seem to be commonplace now so there may be some truth to that. The irony however is that as a society we seem increasingly more fixated on our screens and don't mind the endless text messages and social media and app notifications yet somehow potentially life-saving alerts would be the source of fatigue.
One criticism I've read a few times in the past week has been suggesting that people may have had alert fatigue. While it is true that things like the Weather Channel have contributed a lot of noise(naming winter storms for instance.) Additionally there were 4 separate alerts that went out the night of the flooding. And of course things like Amber alerts and similar seem to be commonplace now so there may be some truth to that. The irony however is that as a society we seem increasingly more fixated on our screens and don't mind the endless text messages and social media and app notifications yet somehow potentially life-saving alerts would be the source of fatigue.
People forget that "superstorm sandy" wasn't even a hurricane, iirc it was a "tropical depression" by the time it got to nyc
If you don't go through it, it must not be that bad.
If you do go through it, it was worse than the category/ windspeed/ storm surge numbers convey.
"You just had to be there! It was way worse than just a tropical depression!"
It was the media experiencing this phenomenon that gave birth to the hyperbolic term "Superstorm Sandy".
Anyone who's actually been through a hurricane saw through it right away.
If you do go through it, it was worse than the category/ windspeed/ storm surge numbers convey.
"You just had to be there! It was way worse than just a tropical depression!"
It was the media experiencing this phenomenon that gave birth to the hyperbolic term "Superstorm Sandy".
Anyone who's actually been through a hurricane saw through it right away.
IIRC what made it a superstorm was that several weather patterns combined and amplified each other. Same thing happened with Ida: there were storms already moving upwards into NYC and Ida just came through and gave it a push.
Sounds reasonable. It's the same thing as a little bit of snow and not-very-cold weather wrecking havoc on Texas.
Being unprepared causes the most deaths
Being unprepared causes the most deaths
News coverage is really dropping the ball on this one. It might not have the optics of Katrina, but it was a far more powerful, even if smaller, storm.
Eg: New Orleans, Baton Rouge, and SE LA power outage maps [0][1][2]
Based on the damage in south Louisiana, it's a miracle there weren't far far more deaths.
The damage to Port Fourchon alone should be national news. Anywhere from 10~30% of the countries oil flows through there, depending on how you measured it. And it got a direct hit.
The gas pipeline fiasco from a few months back? All the refineries feeding it were shut down for over a week. Wait till that lag period catches up.
But for reasons that be, MSM decided this was a non-event until it got to NYC, and even then a relatively minor one. Hard to believe they're not downplaying this on purpose.
[0]https://i.imgur.com/MT1z0n5.jpg
[1]https://i.imgur.com/HpKJlS4.jpg
[2]https://i.imgur.com/618PI36.jpg
Eg: New Orleans, Baton Rouge, and SE LA power outage maps [0][1][2]
Based on the damage in south Louisiana, it's a miracle there weren't far far more deaths.
The damage to Port Fourchon alone should be national news. Anywhere from 10~30% of the countries oil flows through there, depending on how you measured it. And it got a direct hit.
The gas pipeline fiasco from a few months back? All the refineries feeding it were shut down for over a week. Wait till that lag period catches up.
But for reasons that be, MSM decided this was a non-event until it got to NYC, and even then a relatively minor one. Hard to believe they're not downplaying this on purpose.
[0]https://i.imgur.com/MT1z0n5.jpg
[1]https://i.imgur.com/HpKJlS4.jpg
[2]https://i.imgur.com/618PI36.jpg
> MSM decided this was a non-event until it got to NYC, and even then a relatively minor one
The only story the New York Times was covering all week was Ida. Well before it got to the Northeast.
The only story the New York Times was covering all week was Ida. Well before it got to the Northeast.
That's good to hear.
Lake Charles is still waiting on Congressional approval for a relief bill for last year's hurricane damage, so there's some angst.
Cable news seemed stuck on Afghanistan evacuations (which didn't have any developments between the bombing and last wheels up, as far as I can tell).
And the weather channel (and similar) were too busy faking bad conditions in places that were relatively spared.
Ie. the electrical lineman doing cartwheels behind the reporter pretending to be blown over.
Lake Charles is still waiting on Congressional approval for a relief bill for last year's hurricane damage, so there's some angst.
Cable news seemed stuck on Afghanistan evacuations (which didn't have any developments between the bombing and last wheels up, as far as I can tell).
And the weather channel (and similar) were too busy faking bad conditions in places that were relatively spared.
Ie. the electrical lineman doing cartwheels behind the reporter pretending to be blown over.
In other interviews the engineers claim the levees were built to a 200-year level, and that a 100-year level would not have been sufficient for Ida.
If we get 100-year storms every five years, then is that really the correct description?
From the USGS page on 100 year floods (https://www.usgs.gov/special-topic/water-science-school/scie...):
> The term "100-year flood" is used in an attempt to simplify the definition of a flood that statistically has a 1-percent chance of occurring in any given year. Likewise, the term "100-year storm" is used to define a rainfall event that statistically has this same 1-percent chance of occurring. In other words, over the course of 1 million years, these events would be expected to occur 10,000 times. But, just because it rained 10 inches in one day last year doesn't mean it can't rain 10 inches in one day again this year.
And it looks like these terms are based on past data not future projections:
> Since the 100-year flood level is statistically computed using past, existing data, as more data comes in, the level of the 100-year flood will change (especially if a huge flood hits in the current year). As more data are collected, or when a river basin is altered in a way that affects the flow of water in the river, scientists re-evaluate the frequency of flooding.
> The term "100-year flood" is used in an attempt to simplify the definition of a flood that statistically has a 1-percent chance of occurring in any given year. Likewise, the term "100-year storm" is used to define a rainfall event that statistically has this same 1-percent chance of occurring. In other words, over the course of 1 million years, these events would be expected to occur 10,000 times. But, just because it rained 10 inches in one day last year doesn't mean it can't rain 10 inches in one day again this year.
And it looks like these terms are based on past data not future projections:
> Since the 100-year flood level is statistically computed using past, existing data, as more data comes in, the level of the 100-year flood will change (especially if a huge flood hits in the current year). As more data are collected, or when a river basin is altered in a way that affects the flow of water in the river, scientists re-evaluate the frequency of flooding.
The entire rest of the west bank parishes is still protected by the "old" definition of a 100 year storm, and they had multiple breeches this year.
So the taxpayer money wasn't squandered but actually put to good use. Who would have thought?