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Unfortunately it is now uncertain whether any of this matters 100 years from now. It is expected that sea levels will rise by more than 2 meters, and that dykes

Unfortunately it is now uncertain whether any of this matters 100 years from now. It is expected that sea levels will rise by more than 2 meters, and that dykes will no longer work beyond an extra 2 meter extension, not because they can't be extended but because Dutch soil is too soft and seawater will just go under the dyke. Almere will probably be amongst the first to go. It seems nobody has proposed a solution, but in the mean time life goes on as if it won't happen. You don't see this being factored into plans or housing prices.

throwaway6734 4y ago
The US has somewhat similar problem: flood insurance is heavily subsidized by the federal government so the market doesn't remotely factor in future flooding risks into housing prices. There have recently been plans to raise prices but since Florida is such an important state to Federal elections there's a massive political hurdle
- MomoXenosaga 4y ago
  Imagine every American east coast city flooding at the same time. That's what would happen in the Netherlands if the levies break. At least Florida can be abandoned in a worst case scenario and the US would continue to function.
  - mellavora 4y ago
    Florida doesn't really have many evacuation routes. In a worst case scenario it isn't just the land which gets abandoned.
  - jacquesm 4y ago
    No, that's not what would happen. There are a great many secondary and tertiary systems in place, a breach in one place would not automatically flood the whole country, though of course if you lived in the area just behind the breach it would be a major problem. NL has lived with water long enough that the risks are reasonably well understood. Of course nature can still surprise you, the intensity increase of especially rain has caused some pretty serious problems in recent memory. But even though we occasionally have a dike that fails something at the level of 1953 isn't going to happen 'just like that', though you can never entirely rule out the possibility. Much more money has gone into water management since then, it is our 'Los Alamos', special water management taxes have been used for massive investments into infrastructure including pumps, dikes, flood barriers and all kinds of less visible work. It isn't perfect, but it is really quite good and I would much rather live here than a few hundred kilometers upstream during a heavy rain season. At least we are no longer in denial that water management is something that you postpone until after the flood.
    - throwaway6734 4y ago
      Does the Netherlands export their knowledge of handling below sea level engineering? With coasts around the world more prone to flooding it seems like it could be a lucrative industry
      - jacquesm 4y ago
        Yes, absolutely. Kansai airport and the recovery of New Orleans were to some extent (from an engineering point of view) a Dutch effort. For instance: https://nltimes.nl/2017/08/30/new-orleans-turns-netherlands-help-dealing-floods https://nltimes.nl/2017/08/30/new-orleans-turns-netherlands-... One interesting bit about the Kansai Airport work was that the Dutch advised the Japanese to leave the reclaimed land untouched for a while (20 years or so) so it could settle, the Japanese ignored the advice because they had run the numbers and realized dealing with the damage from the settling was more profitable. We're cheap, it's a local joke that copper wire was invented by two Dutch traders fighting over a single coin, I think the idea of wasting good materials on unstable ground just didn't sit right with the Dutch engineers but the Japanese had no problem with it at all. I wonder how the Japanese look at this today from a financial perspective. https://www.smithsonianmag.com/air-space-magazine/how-to-save-a-sinking-airport-180968985/ https://www.smithsonianmag.com/air-space-magazine/how-to-sav... Edit: I originally wrote Narita, instead of Kansai.
        throwaway6734 4y ago
        Thanks! >We're cheap, it's a local joke that copper wire was invented by two Dutch traders fighting over a single coin lmao
      - vladms 4y ago
        They definitely export their knowledge of working with sand and water: https://www.aljazeera.com/news/2013/11/18/dutch-firm-agrees-dubai-island-deal https://www.aljazeera.com/news/2013/11/18/dutch-firm-agrees-... And same company has other similar/related projects like: https://www.vanoord.com/en/updates/van-oord-awarded-land-reclamation-project-maldives https://www.vanoord.com/en/updates/van-oord-awarded-land-rec...
jacquesm 4y ago
This isn't as big a problem as some make it out to be. The dikes have always been a porous solution, not perfect, 'kwel' (water that seeps under the dike) has been there as long as there are dikes. But concentric circles of staged dikes are one way in which you could deal with this. It will require massive geo engineering but nothing on a scale that the Dutch have not done before. There are some voices that NL will have to abandon terrain, I think we'll see the exact opposite: more terrain will be created with the express goal of being used as basins for increased control over water. The important bit when you construct dikes is the delta between the water table on one side of the dike and on the other and we already have areas where there are three such dikes in a row to be able to deal with fairly extreme differences in water levels. If you drive or cycle in the North of the country every now and then you'll find yourself crossing through a dike with a concrete lintel built into the dike body, this is where in the case of high water the dike can very rapidly be closed again and turned into a functioning part of the water defenses. Those dikes are called 'sleeping' dikes they are still there and ready to be activated but normally they are transparent to traffic. https://en.wikipedia.org/wiki/Sleeper_dike https://en.wikipedia.org/wiki/Sleeper_dike https://www.climatechangepost.com/netherlands/coastal-floods/ https://www.climatechangepost.com/netherlands/coastal-floods... Other evidence that this can be done is that there are some massive artificial lakes constructed all over the world with dams that have a 'head' that is much higher than anything that NL will ever have to deal with. A bigger problem than keeping the sea out will be to deal with the rain water coming into the Netherlands by way of the very large rivers. These carry massive flow (from a total area much, much larger than that of the country itself) during some times of the year and to accommodate that flow and ensure that the land behind the river dikes doesn't flood is - in my opinion - a much bigger problem when the sea level rises. During some storms you see a reversal in the flow of the rivers in the delta. Several interesting constructs are located near Rotterdam and Zeeland, transparent to shipping but it can be closed quickly if such reverse flow threatens the land: https://www.rijkswaterstaat.nl/water/waterbeheer/bescherming-tegen-het-water/waterkeringen/stormvloedkeringen https://www.rijkswaterstaat.nl/water/waterbeheer/bescherming... (Dutch) Those 'pie slices' are as large as the Eiffel tower but mobile, and are some of the most impressive engineering works that I've seen in my life.
- whazor 4y ago
FooBarWidget 4y ago
Not sure what the downvotes are for. I live here and I worry about what happens if I buy a new house (which is ridiculously expensive nowadays — like 3x-4x more expensive than just 5 years ago) — will I be able to sell it in 30 years when people start worrying about 30% of the country flooding in another 30 years? It's not some nutjob idea that only I have, the newspapers have written about how the market currently completely ignores the issue: https://www.trouw.nl/duurzaamheid-natuur/wanneer-zullen-klimaatzorgen-de-huizenprijs-doen-kelderen~b3d999ec/ https://www.trouw.nl/duurzaamheid-natuur/wanneer-zullen-klim... In my pension plans I already planned for the worse by assuming that my house will be devalued by 50% rather than having risen in value. jacquesm seems to believe that we have a solution. That's not the sentiment being brought forward by the newspapers. Even reputable newspapers are like "this time we're really screwed, we can't win this one". I'm not a water management expert so I don't know any better than what I hear, but I've yet to hear from someone authoritative that it's going to be okay — the authorities just seem to be quiet on this issue. That really doesn't help me with my long-term plans.
- jacquesm 4y ago
  If you're nervous about this go visit the Delta works and the various storm barriers, then look at them when there is a really bad storm and check the margins. You'll be fine, unless you will live to be 300 or so, on those timescales anything could happen. But the next 100 years are definitely covered. I would not buy anything in Venice though, they will likely be done for and we'll remember it like we remember Atlantis. Money + engineering are a pretty good combination, similar to how Japan manages to do quite well in spite of very bad and regular earthquakes. I think the way the Dutch deal with water is probably best described as symbiotic, we don't force it but we guide it and when we really can't do it any other way we'll bring out the pumps. Oh, that's another one for your list of stuff to visit: the pump cassettes next to IJmuiden's Northern most locks, those things are straight from a SF movie, 260 cubic meters per second.

throwaway6734 4y ago

The US has somewhat similar problem: flood insurance is heavily subsidized by the federal government so the market doesn't remotely factor in future flooding risks into housing prices. There have recently been plans to raise prices but since Florida is such an important state to Federal elections there's a massive political hurdle

MomoXenosaga 4y ago
Imagine every American east coast city flooding at the same time. That's what would happen in the Netherlands if the levies break. At least Florida can be abandoned in a worst case scenario and the US would continue to function.
- mellavora 4y ago
  Florida doesn't really have many evacuation routes. In a worst case scenario it isn't just the land which gets abandoned.
- jacquesm 4y ago
  No, that's not what would happen. There are a great many secondary and tertiary systems in place, a breach in one place would not automatically flood the whole country, though of course if you lived in the area just behind the breach it would be a major problem. NL has lived with water long enough that the risks are reasonably well understood. Of course nature can still surprise you, the intensity increase of especially rain has caused some pretty serious problems in recent memory. But even though we occasionally have a dike that fails something at the level of 1953 isn't going to happen 'just like that', though you can never entirely rule out the possibility. Much more money has gone into water management since then, it is our 'Los Alamos', special water management taxes have been used for massive investments into infrastructure including pumps, dikes, flood barriers and all kinds of less visible work. It isn't perfect, but it is really quite good and I would much rather live here than a few hundred kilometers upstream during a heavy rain season. At least we are no longer in denial that water management is something that you postpone until after the flood.
  - throwaway6734 4y ago
    Does the Netherlands export their knowledge of handling below sea level engineering? With coasts around the world more prone to flooding it seems like it could be a lucrative industry
    - jacquesm 4y ago
      Yes, absolutely. Kansai airport and the recovery of New Orleans were to some extent (from an engineering point of view) a Dutch effort. For instance: https://nltimes.nl/2017/08/30/new-orleans-turns-netherlands-help-dealing-floods https://nltimes.nl/2017/08/30/new-orleans-turns-netherlands-... One interesting bit about the Kansai Airport work was that the Dutch advised the Japanese to leave the reclaimed land untouched for a while (20 years or so) so it could settle, the Japanese ignored the advice because they had run the numbers and realized dealing with the damage from the settling was more profitable. We're cheap, it's a local joke that copper wire was invented by two Dutch traders fighting over a single coin, I think the idea of wasting good materials on unstable ground just didn't sit right with the Dutch engineers but the Japanese had no problem with it at all. I wonder how the Japanese look at this today from a financial perspective. https://www.smithsonianmag.com/air-space-magazine/how-to-save-a-sinking-airport-180968985/ https://www.smithsonianmag.com/air-space-magazine/how-to-sav... Edit: I originally wrote Narita, instead of Kansai.
      - throwaway6734 4y ago
        Thanks! >We're cheap, it's a local joke that copper wire was invented by two Dutch traders fighting over a single coin lmao
    - vladms 4y ago
      They definitely export their knowledge of working with sand and water: https://www.aljazeera.com/news/2013/11/18/dutch-firm-agrees-dubai-island-deal https://www.aljazeera.com/news/2013/11/18/dutch-firm-agrees-... And same company has other similar/related projects like: https://www.vanoord.com/en/updates/van-oord-awarded-land-reclamation-project-maldives https://www.vanoord.com/en/updates/van-oord-awarded-land-rec...

jacquesm 4y ago

This isn't as big a problem as some make it out to be. The dikes have always been a porous solution, not perfect, 'kwel' (water that seeps under the dike) has been there as long as there are dikes. But concentric circles of staged dikes are one way in which you could deal with this. It will require massive geo engineering but nothing on a scale that the Dutch have not done before. There are some voices that NL will have to abandon terrain, I think we'll see the exact opposite: more terrain will be created with the express goal of being used as basins for increased control over water. The important bit when you construct dikes is the delta between the water table on one side of the dike and on the other and we already have areas where there are three such dikes in a row to be able to deal with fairly extreme differences in water levels. If you drive or cycle in the North of the country every now and then you'll find yourself crossing through a dike with a concrete lintel built into the dike body, this is where in the case of high water the dike can very rapidly be closed again and turned into a functioning part of the water defenses. Those dikes are called 'sleeping' dikes they are still there and ready to be activated but normally they are transparent to traffic. https://en.wikipedia.org/wiki/Sleeper_dike https://en.wikipedia.org/wiki/Sleeper_dike https://www.climatechangepost.com/netherlands/coastal-floods/ https://www.climatechangepost.com/netherlands/coastal-floods... Other evidence that this can be done is that there are some massive artificial lakes constructed all over the world with dams that have a 'head' that is much higher than anything that NL will ever have to deal with. A bigger problem than keeping the sea out will be to deal with the rain water coming into the Netherlands by way of the very large rivers. These carry massive flow (from a total area much, much larger than that of the country itself) during some times of the year and to accommodate that flow and ensure that the land behind the river dikes doesn't flood is - in my opinion - a much bigger problem when the sea level rises. During some storms you see a reversal in the flow of the rivers in the delta. Several interesting constructs are located near Rotterdam and Zeeland, transparent to shipping but it can be closed quickly if such reverse flow threatens the land: https://www.rijkswaterstaat.nl/water/waterbeheer/bescherming-tegen-het-water/waterkeringen/stormvloedkeringen https://www.rijkswaterstaat.nl/water/waterbeheer/bescherming... (Dutch) Those 'pie slices' are as large as the Eiffel tower but mobile, and are some of the most impressive engineering works that I've seen in my life.

whazor 4y ago

FooBarWidget 4y ago

Not sure what the downvotes are for. I live here and I worry about what happens if I buy a new house (which is ridiculously expensive nowadays — like 3x-4x more expensive than just 5 years ago) — will I be able to sell it in 30 years when people start worrying about 30% of the country flooding in another 30 years? It's not some nutjob idea that only I have, the newspapers have written about how the market currently completely ignores the issue: https://www.trouw.nl/duurzaamheid-natuur/wanneer-zullen-klimaatzorgen-de-huizenprijs-doen-kelderen~b3d999ec/ https://www.trouw.nl/duurzaamheid-natuur/wanneer-zullen-klim... In my pension plans I already planned for the worse by assuming that my house will be devalued by 50% rather than having risen in value. jacquesm seems to believe that we have a solution. That's not the sentiment being brought forward by the newspapers. Even reputable newspapers are like "this time we're really screwed, we can't win this one". I'm not a water management expert so I don't know any better than what I hear, but I've yet to hear from someone authoritative that it's going to be okay — the authorities just seem to be quiet on this issue. That really doesn't help me with my long-term plans.

jacquesm 4y ago
If you're nervous about this go visit the Delta works and the various storm barriers, then look at them when there is a really bad storm and check the margins. You'll be fine, unless you will live to be 300 or so, on those timescales anything could happen. But the next 100 years are definitely covered. I would not buy anything in Venice though, they will likely be done for and we'll remember it like we remember Atlantis. Money + engineering are a pretty good combination, similar to how Japan manages to do quite well in spite of very bad and regular earthquakes. I think the way the Dutch deal with water is probably best described as symbiotic, we don't force it but we guide it and when we really can't do it any other way we'll bring out the pumps. Oh, that's another one for your list of stuff to visit: the pump cassettes next to IJmuiden's Northern most locks, those things are straight from a SF movie, 260 cubic meters per second.