7 ms·

UK Weather: Flooding in London after heavy rain

91 points by montalbano 5y ago

m-i-l 5y ago
Second time in under 2 weeks[0]. I wonder how much of this is related to people having paved over their lawns and gardens. [0] https://www.bbc.co.uk/news/av/uk-57811613 https://www.bbc.co.uk/news/av/uk-57811613 from 12 July
- montalbano 5y ago
  Do you have any data suggesting there has been rapid paving of lawns and gardens since last year?
  - makomk 5y ago
    There's no reason why it would be caused merely by paving over of lawns and gardens in the last year - there's a lot of year-to-year variation in weather like this, and without sufficient advance planning and restrictions to enforce this, it's really easy to build in ways that get away without flooding for a few years or even decades until they don't.
- simonh 5y ago
  That won’t help, of course, but that doesn’t change the fact these really are extreme weather events. They’d be causing damage and disruption anyway. I live in south east London. Last week my wife was driving home in a rain burst, she got stuck in traffic and took video of water gushing up out of a drain like a fountain. The road was near the bottom of a valley, and the pressure in the drain pipes running down the hill must have been enormous.
- objclxt 5y ago
  > I wonder how much of this is related to people having paved over their lawns and gardens. Whilst that may well contribute, the main cause here was just the sheer volume of water in such a short space of time. I was right under the thunderstorm, we had about 80mm of rainfall in a couple of hours. That’s the equivalent of two months of normal rainfall this time of year. When you get it coming in that quickly the water is going to run off everything.
  - mrec 5y ago
    Yeah, same here, it was pretty impressive. Worth noting too that this is coming directly on the heels of a week+ long heatwave, so unpaved ground is going to be baked hard and won't be soaking up much. (During water shortages TPTB always comment that summer rain doesn't help much, winter rain is the thing.)
- vondur 5y ago
  In Southern California we’ve paved almost everything from the Ocean until 50 or 60 miles inland.
- dan-robertson 5y ago
  Pavement definitely soaks up less water than a lawn but note that the soil in London is rich in clay so it doesn’t drain quickly. I would expect there are plenty of waterlogged fields at the moment, though runoff from paved land surely doesn’t help.
montalbano 5y ago
This is the second time in a few weeks that there has been unprecedented surface water (rain, not river) induced flooding in many parts of London. An NYT article from 13th July: https://www.nytimes.com/2021/07/13/world/europe/uk-london-floods.html https://www.nytimes.com/2021/07/13/world/europe/uk-london-fl...
- simonh 5y ago
  It’s been an incredible year. Blizzards in Texas, burning heat in the northwest US, intense rain bursts in Europe and China. Then of course in the last few years extreme forest fires in Australia, the US and Brazil. Steadily worsening hurricanes. Climate scientists have been predicting more extreme weather for decades. This is just the early phase.
  - firebaze 5y ago
    If this is caused by climate change, we're probably doomed. Suppose there is at least a 50 year latency between human emissions and effect on weather, we're just starting to feel the effects of the past. I really hope this is just a statistical effect, but it feels like it isn't. Crossing Fingers.
    - loopz 5y ago
      The graph in the middle of this page shows for last 2k years. https://www.visualcapitalist.com/global-temperature-graph-1851-2020/ https://www.visualcapitalist.com/global-temperature-graph-18... It's not like we didn't get any warnings or didn't see it coming.
      - throwaway888abc 5y ago
        xkcd layman version https://xkcd.com/1732/ https://xkcd.com/1732/
    - madaxe_again 5y ago
      It’s not really a latency effect - it’s more of a phase change, as you shift from one chaotic oscillation mode to another, and we’ve finally managed to get enough energy into the system to make it find a new mode. What we have now is the previous mode faltering and wobbling out of its relatively stable phase, into… who knows. Fun thing about chaotic systems - they’re chaotic. You can’t just put the parameters back to where they were and expect the same system you had to reestablish. There’s no “undo”, and modelling rapidly runs out of ideas - our best forecasts are so-so at best. Layer atop that the chaotic systems of humanity, and you’ve got… an interesting interaction. You don’t need the entire world to burn for systems to collapse - you just need to watch the underwriters collapse, as you spend more and more of your GDP on cleaning up the mess and security, and run out of money for anything else. Meanwhile, crops fail, and food becomes increasingly erratic in supply. We’ll turn on each other long before the climate kills us directly. I for one do not expect to die of old age.
walterbell 5y ago
If drones can encourage rain, could they be used to delay rain or spread it out over a longer time? https://interestingengineering.com/the-uae-is-using-drones-to-control-dubais-weather https://interestingengineering.com/the-uae-is-using-drones-t... > rain-controlling drones engineered by the University of Reading. The drones don't create rain themselves but help to jump-start rain production via cloud seeding. They "zap" the clouds with an electric charge, subsequently charging the droplets inside. Since the beginning of 2021, the National Center of Meteorology (NCM) has conducted 126 instances of cloud seeding.
- simonh 5y ago
  I think the idea is to seed rain to get moisture out of the air mass before it builds up too much, or before it hits population centres.
binbag 5y ago
I look forward to Westminster taking climate change more seriously now…
- deleted 5y ago
  [deleted]
- bArray 5y ago
  > I look forward to Westminster taking climate change more seriously now… Despite talk of the environment in the recent G7 meeting, I suspect it's going to take a backseat to economic recovery. You have the ongoing issues from Brexit and the fact that the government (and their opposition) have an impossible standard for COVID vaccine success. Also I'd be interested to hear what you want to see Westminster do. I've heard a lot of ideas being thrown around, but I remain sceptical.
  - binbag 5y ago
    I don’t know the solution, but I’m not currently in charge of a G7 member state.
    - bArray 5y ago
      > I don’t know the solution, but I’m not currently in charge of a G7 member state. Fair enough. I would urge against asking for change simply because you find a problem - the proposed solution may end up being worse in the long run. There are multiple examples of this in the global warming context. For example, every government used to ship their recycling rubbish all the way around the world to places like China, who would then just sit on it or fill up their own landfills. Another example is a biodegradable plastic bag that ended up hindering the composting process more than the original plastic. Another example is a CFC reduction program, where reducing the amount of certain chemicals would earn 'green points' that could be negated from carbon emissions - governments just started purposely creating these dangerous chemicals and destroying them in order to earn points to offset against their emissions.
- atc 5y ago
mattlondon 5y ago
The first time this hit a week or two ago our patio "flooded" to about 4 or 5 cm deep in water alarmingly quickly. I grabbed a broom and jiggled around the drain to remove some leaves/twigs/mud and it cleared within 30 seconds. Today, no flood on our patio I wonder what the state of the drains are in most of London's streets considering the recent lack of basic services due to covid... This is not exactly new - its not like we don't get rain in London so I am surprised this is happening quite so frequently It would not surprise me to hear that basic street cleaning has been totally neglected for the past 18 months
- gerdesj 5y ago
  Pop down to Screwfix or whatever and grab a set of drain rods (about £30-50) and some manhole cover lifters (a few quid). Some long flat screwdrivers and a jemmy are also useful for lifting covers. Wear marigolds or marigolds under rigger gloves or those red coloured anti chemical gloves (watch out for holes.) Find out what is your responsibility to keep clear. The drains are fine for what they are designed to deal with which is weather as it was known many decades ago. All that stuff is designed to deal with a 1 in n year event eg a 1 in 100 year event or 1 in 500 or 1 in 1000 etc. The problem is that 1 in 100 year events are happening nearly annually these days. It's not quite as bad as that but not far off. Have a think about where you are in relation to flooding events because they will happen more often and with increasing severity where you are. If you have a mate who is a Civil Engineer or a Hydrologist, works in Flooding in the Environmental Agency or other useful type, instead of a banker or IT (I'm an ex Civ Eng and now work in IT - bloody useless) then buy them a beer or two and ask for advice. Keep your drains clear and your guttering too.
  - kortilla 5y ago
    > The problem is that 1 in 100 year events are happening nearly annually these days. But that doesn’t matter if they are actually designed to handle 1 in 100 year events. If the drains can’t handle a storm it means it wasn’t implemented to do so, whether it happens annually or once every 50 years.
    - 5y ago
scns 5y ago
How bad is it? In germany cars swam, several people died.
- dan-robertson 5y ago
  I don’t think many people will die (if anyone). The video in the article had a few people who either abandoned their cars or foolishly drove them deeper on flooded roads. The flooded underground stations look scary. I just don’t know how good we are about draining stations/tunnels/preventing flooding there (once upon a time, there were floodgates at the doors to the platform at stations near tunnels under the Thames but I don’t think they are operational at all.) The flooding is less bad than flooding in Germany (something like 10-00 dead? Many evacuated or disrupted) and much less bad than in zhengzhou (likely over 10k but obviously government trying to cover it up.)
deleted 5y ago
[deleted]
anonymousiam 5y ago
Remarkable how fast the climate can change: https://www.bbc.co.uk/news/uk-17373803 https://www.bbc.co.uk/news/uk-17373803
- dan-robertson 5y ago
  Is it actually remarkable? We had hosepipe bans at various times decades ago and hot sunny weather is frequently followed by thunderstorms. There has always been between years with some being hotter or wetter or colder or snowier or drier. I don’t think there is much of a trend to be observed by one day of 2021 and a portion of the weather of 2012. Maybe it is still remarkable but it is also surely typical.
  - anonymousiam 5y ago
    You are agreeing with my point. Sorry I left the sarcasm tags off my comment. Climate has often been confused with weather, and the BBC should not be claiming "drought" based upon such a short interval.
Jedd 5y ago
When I was living in London back in 1999, one of my friends was working on the Jubilee Line Extension (JLE) project, which was extending the tube/underground out to the east. He told me that the bilge pumps running in many parts of the London underground are running 24/7, simply because the water table is so high (and the underground is very deep in some places). During normal weather, if those pumps go offline for more than 15 minutes they have a major flooding problem. Doubtless that situation has worsened over the past two decades. London is very flat and very low -- they're going to be an unfortunate poster child for coastal cities being slowly but inexorably wiped out by sea level rise.
- CodeGlitch 5y ago
  Perhaps we should start asking the Dutch how they do it: https://www.thoughtco.com/polders-and-dikes-of-the-netherlands-1435535 https://www.thoughtco.com/polders-and-dikes-of-the-netherlan...
- spixy 5y ago
  Thames Barrier should be enough at least till 2030.

91 points by montalbano 5y ago

Second time in under 2 weeks[0]. I wonder how much of this is related to people having paved over their lawns and gardens. [0] https://www.bbc.co.uk/news/av/uk-57811613 https://www.bbc.co.uk/news/av/uk-57811613 from 12 July

montalbano 5y ago
Do you have any data suggesting there has been rapid paving of lawns and gardens since last year?
- makomk 5y ago
  There's no reason why it would be caused merely by paving over of lawns and gardens in the last year - there's a lot of year-to-year variation in weather like this, and without sufficient advance planning and restrictions to enforce this, it's really easy to build in ways that get away without flooding for a few years or even decades until they don't.
simonh 5y ago
That won’t help, of course, but that doesn’t change the fact these really are extreme weather events. They’d be causing damage and disruption anyway. I live in south east London. Last week my wife was driving home in a rain burst, she got stuck in traffic and took video of water gushing up out of a drain like a fountain. The road was near the bottom of a valley, and the pressure in the drain pipes running down the hill must have been enormous.
objclxt 5y ago
> I wonder how much of this is related to people having paved over their lawns and gardens. Whilst that may well contribute, the main cause here was just the sheer volume of water in such a short space of time. I was right under the thunderstorm, we had about 80mm of rainfall in a couple of hours. That’s the equivalent of two months of normal rainfall this time of year. When you get it coming in that quickly the water is going to run off everything.
- mrec 5y ago
  Yeah, same here, it was pretty impressive. Worth noting too that this is coming directly on the heels of a week+ long heatwave, so unpaved ground is going to be baked hard and won't be soaking up much. (During water shortages TPTB always comment that summer rain doesn't help much, winter rain is the thing.)
vondur 5y ago
In Southern California we’ve paved almost everything from the Ocean until 50 or 60 miles inland.
dan-robertson 5y ago
Pavement definitely soaks up less water than a lawn but note that the soil in London is rich in clay so it doesn’t drain quickly. I would expect there are plenty of waterlogged fields at the moment, though runoff from paved land surely doesn’t help.

montalbano 5y ago

This is the second time in a few weeks that there has been unprecedented surface water (rain, not river) induced flooding in many parts of London. An NYT article from 13th July: https://www.nytimes.com/2021/07/13/world/europe/uk-london-floods.html https://www.nytimes.com/2021/07/13/world/europe/uk-london-fl...

simonh 5y ago
It’s been an incredible year. Blizzards in Texas, burning heat in the northwest US, intense rain bursts in Europe and China. Then of course in the last few years extreme forest fires in Australia, the US and Brazil. Steadily worsening hurricanes. Climate scientists have been predicting more extreme weather for decades. This is just the early phase.
- firebaze 5y ago
  If this is caused by climate change, we're probably doomed. Suppose there is at least a 50 year latency between human emissions and effect on weather, we're just starting to feel the effects of the past. I really hope this is just a statistical effect, but it feels like it isn't. Crossing Fingers.
  - loopz 5y ago
    The graph in the middle of this page shows for last 2k years. https://www.visualcapitalist.com/global-temperature-graph-1851-2020/ https://www.visualcapitalist.com/global-temperature-graph-18... It's not like we didn't get any warnings or didn't see it coming.
    - throwaway888abc 5y ago
      xkcd layman version https://xkcd.com/1732/ https://xkcd.com/1732/
  - madaxe_again 5y ago
    It’s not really a latency effect - it’s more of a phase change, as you shift from one chaotic oscillation mode to another, and we’ve finally managed to get enough energy into the system to make it find a new mode. What we have now is the previous mode faltering and wobbling out of its relatively stable phase, into… who knows. Fun thing about chaotic systems - they’re chaotic. You can’t just put the parameters back to where they were and expect the same system you had to reestablish. There’s no “undo”, and modelling rapidly runs out of ideas - our best forecasts are so-so at best. Layer atop that the chaotic systems of humanity, and you’ve got… an interesting interaction. You don’t need the entire world to burn for systems to collapse - you just need to watch the underwriters collapse, as you spend more and more of your GDP on cleaning up the mess and security, and run out of money for anything else. Meanwhile, crops fail, and food becomes increasingly erratic in supply. We’ll turn on each other long before the climate kills us directly. I for one do not expect to die of old age.

walterbell 5y ago

If drones can encourage rain, could they be used to delay rain or spread it out over a longer time? https://interestingengineering.com/the-uae-is-using-drones-to-control-dubais-weather https://interestingengineering.com/the-uae-is-using-drones-t... > rain-controlling drones engineered by the University of Reading. The drones don't create rain themselves but help to jump-start rain production via cloud seeding. They "zap" the clouds with an electric charge, subsequently charging the droplets inside. Since the beginning of 2021, the National Center of Meteorology (NCM) has conducted 126 instances of cloud seeding.

simonh 5y ago
I think the idea is to seed rain to get moisture out of the air mass before it builds up too much, or before it hits population centres.

binbag 5y ago

I look forward to Westminster taking climate change more seriously now…

deleted 5y ago
[deleted]
bArray 5y ago
> I look forward to Westminster taking climate change more seriously now… Despite talk of the environment in the recent G7 meeting, I suspect it's going to take a backseat to economic recovery. You have the ongoing issues from Brexit and the fact that the government (and their opposition) have an impossible standard for COVID vaccine success. Also I'd be interested to hear what you want to see Westminster do. I've heard a lot of ideas being thrown around, but I remain sceptical.
- binbag 5y ago
  I don’t know the solution, but I’m not currently in charge of a G7 member state.
  - bArray 5y ago
    > I don’t know the solution, but I’m not currently in charge of a G7 member state. Fair enough. I would urge against asking for change simply because you find a problem - the proposed solution may end up being worse in the long run. There are multiple examples of this in the global warming context. For example, every government used to ship their recycling rubbish all the way around the world to places like China, who would then just sit on it or fill up their own landfills. Another example is a biodegradable plastic bag that ended up hindering the composting process more than the original plastic. Another example is a CFC reduction program, where reducing the amount of certain chemicals would earn 'green points' that could be negated from carbon emissions - governments just started purposely creating these dangerous chemicals and destroying them in order to earn points to offset against their emissions.
atc 5y ago

mattlondon 5y ago

The first time this hit a week or two ago our patio "flooded" to about 4 or 5 cm deep in water alarmingly quickly. I grabbed a broom and jiggled around the drain to remove some leaves/twigs/mud and it cleared within 30 seconds. Today, no flood on our patio I wonder what the state of the drains are in most of London's streets considering the recent lack of basic services due to covid... This is not exactly new - its not like we don't get rain in London so I am surprised this is happening quite so frequently It would not surprise me to hear that basic street cleaning has been totally neglected for the past 18 months

gerdesj 5y ago
Pop down to Screwfix or whatever and grab a set of drain rods (about £30-50) and some manhole cover lifters (a few quid). Some long flat screwdrivers and a jemmy are also useful for lifting covers. Wear marigolds or marigolds under rigger gloves or those red coloured anti chemical gloves (watch out for holes.) Find out what is your responsibility to keep clear. The drains are fine for what they are designed to deal with which is weather as it was known many decades ago. All that stuff is designed to deal with a 1 in n year event eg a 1 in 100 year event or 1 in 500 or 1 in 1000 etc. The problem is that 1 in 100 year events are happening nearly annually these days. It's not quite as bad as that but not far off. Have a think about where you are in relation to flooding events because they will happen more often and with increasing severity where you are. If you have a mate who is a Civil Engineer or a Hydrologist, works in Flooding in the Environmental Agency or other useful type, instead of a banker or IT (I'm an ex Civ Eng and now work in IT - bloody useless) then buy them a beer or two and ask for advice. Keep your drains clear and your guttering too.
- kortilla 5y ago
  > The problem is that 1 in 100 year events are happening nearly annually these days. But that doesn’t matter if they are actually designed to handle 1 in 100 year events. If the drains can’t handle a storm it means it wasn’t implemented to do so, whether it happens annually or once every 50 years.
  - 5y ago

scns 5y ago

How bad is it? In germany cars swam, several people died.

dan-robertson 5y ago
I don’t think many people will die (if anyone). The video in the article had a few people who either abandoned their cars or foolishly drove them deeper on flooded roads. The flooded underground stations look scary. I just don’t know how good we are about draining stations/tunnels/preventing flooding there (once upon a time, there were floodgates at the doors to the platform at stations near tunnels under the Thames but I don’t think they are operational at all.) The flooding is less bad than flooding in Germany (something like 10-00 dead? Many evacuated or disrupted) and much less bad than in zhengzhou (likely over 10k but obviously government trying to cover it up.)

deleted 5y ago

[deleted]

anonymousiam 5y ago

Remarkable how fast the climate can change: https://www.bbc.co.uk/news/uk-17373803 https://www.bbc.co.uk/news/uk-17373803

dan-robertson 5y ago
Is it actually remarkable? We had hosepipe bans at various times decades ago and hot sunny weather is frequently followed by thunderstorms. There has always been between years with some being hotter or wetter or colder or snowier or drier. I don’t think there is much of a trend to be observed by one day of 2021 and a portion of the weather of 2012. Maybe it is still remarkable but it is also surely typical.
- anonymousiam 5y ago
  You are agreeing with my point. Sorry I left the sarcasm tags off my comment. Climate has often been confused with weather, and the BBC should not be claiming "drought" based upon such a short interval.

Jedd 5y ago

When I was living in London back in 1999, one of my friends was working on the Jubilee Line Extension (JLE) project, which was extending the tube/underground out to the east. He told me that the bilge pumps running in many parts of the London underground are running 24/7, simply because the water table is so high (and the underground is very deep in some places). During normal weather, if those pumps go offline for more than 15 minutes they have a major flooding problem. Doubtless that situation has worsened over the past two decades. London is very flat and very low -- they're going to be an unfortunate poster child for coastal cities being slowly but inexorably wiped out by sea level rise.

CodeGlitch 5y ago
Perhaps we should start asking the Dutch how they do it: https://www.thoughtco.com/polders-and-dikes-of-the-netherlands-1435535 https://www.thoughtco.com/polders-and-dikes-of-the-netherlan...
spixy 5y ago
Thames Barrier should be enough at least till 2030.