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The article completely misses the mark. Major rain events in coastal cities is about rapid drainage with high capacity drain channels. Fixating on absorption

The article completely misses the mark. Major rain events in coastal cities is about rapid drainage with high capacity drain channels. Fixating on absorption is not effective and much more costly.

Retric 5y ago
Large coastal cities have issues because they lack elevation over sea level making high capacity drain channels alone ineffective. They need huge pumps to handle storms like this and buffering water ends up being significantly more cost effective. Critically pumps break down whole absorption is more resilient.
- volkl48 5y ago
  Soils have limits to their absorption. July was the wettest one in recorded history in NYC, August was the 4th wettest. And Ida dropped over 3" of rain in a single hour - the highest ever recorded (and >7" of rain for the day - 5th highest ever recorded). The ground was already saturated and unable to absorb much more before Ida showed up. I don't think any realistic amount of additional absorption-based strategies would have accomplished much here.
  - jazzyjackson 5y ago
    there’s more to absorption than whether the dirt is saturated the more trees and roots that exist in that dirt, the more quickly water is drawn away by capillary action (you see, the roots are a series of tubes…)
  - Retric 5y ago
    Absorption isn’t limited to soils capacity. A basin in Central Park could have held 7” of rain * 1.3 square miles until it was absorbed by the soil. Change nothing else and there would have been significantly less flooding.
inetknght 5y ago
Most coastal cities aren't in California. There's nowhere to drain to when the flood has arrived.
sp332 5y ago
Drain to where?
- jazzyjackson 5y ago
  haven’t you ever heard of a cistern? “ The floodwater cathedral hidden 22 meters underground is part of the Metropolitan Area Outer Underground Discharge Channel (MAOUDC), a 6.3 km long system of tunnels and towering cylindrical chambers that protect North Tokyo from flooding.” - https://www.bbc.com/future/article/20181129-the-underground-cathedral-protecting-tokyo-from-floods https://www.bbc.com/future/article/20181129-the-underground-...
  - techdragon 5y ago
    This kind of hidden engineering is just amazing. I love finding out about huge construction projects like this that you might never even notice. Just under your feet… making the world work.
    - _Algernon_ 5y ago
      Tom Scott has a video about it: https://www.youtube.com/watch?v=cfJOW2PtrGk https://www.youtube.com/watch?v=cfJOW2PtrGk

The article completely misses the mark. Major rain events in coastal cities is about rapid drainage with high capacity drain channels. Fixating on absorption is not effective and much more costly.

Retric 5y ago

Large coastal cities have issues because they lack elevation over sea level making high capacity drain channels alone ineffective. They need huge pumps to handle storms like this and buffering water ends up being significantly more cost effective. Critically pumps break down whole absorption is more resilient.

volkl48 5y ago
Soils have limits to their absorption. July was the wettest one in recorded history in NYC, August was the 4th wettest. And Ida dropped over 3" of rain in a single hour - the highest ever recorded (and >7" of rain for the day - 5th highest ever recorded). The ground was already saturated and unable to absorb much more before Ida showed up. I don't think any realistic amount of additional absorption-based strategies would have accomplished much here.
- jazzyjackson 5y ago
  there’s more to absorption than whether the dirt is saturated the more trees and roots that exist in that dirt, the more quickly water is drawn away by capillary action (you see, the roots are a series of tubes…)
- Retric 5y ago
  Absorption isn’t limited to soils capacity. A basin in Central Park could have held 7” of rain * 1.3 square miles until it was absorbed by the soil. Change nothing else and there would have been significantly less flooding.

inetknght 5y ago

Most coastal cities aren't in California. There's nowhere to drain to when the flood has arrived.

sp332 5y ago

Drain to where?

jazzyjackson 5y ago
haven’t you ever heard of a cistern? “ The floodwater cathedral hidden 22 meters underground is part of the Metropolitan Area Outer Underground Discharge Channel (MAOUDC), a 6.3 km long system of tunnels and towering cylindrical chambers that protect North Tokyo from flooding.” - https://www.bbc.com/future/article/20181129-the-underground-cathedral-protecting-tokyo-from-floods https://www.bbc.com/future/article/20181129-the-underground-...
- techdragon 5y ago
  This kind of hidden engineering is just amazing. I love finding out about huge construction projects like this that you might never even notice. Just under your feet… making the world work.
  - _Algernon_ 5y ago
    Tom Scott has a video about it: https://www.youtube.com/watch?v=cfJOW2PtrGk https://www.youtube.com/watch?v=cfJOW2PtrGk