Why do we continue to build in Floodplains? Population and revenue?
February 2, 2020 9:59 AM Subscribe
Higher density populations in coastal locations, development pressures and revenue?
Are there examples of strict construction standards, resilient and flood protected design in floodplains? Are there any that take predicted rising sea levels into account? And specific to NYC, do the requirements equally cover Residential, as well as Commercial and Manufacturing construction?
As for why: where rivers and oceans meet are the crossroads of commerce and culture. Moving goods and people by water is efficient. Water provides power, irrigation and sanitation. Counterintuitively it is cheaper to build in flood plains over the long term in spite of the occasional disaster. Add to that the fact that human disasters occur where humans live. If everyone moved into the hills the disasters would happen there.
posted by klanawa at 1:33 PM on February 2, 2020
posted by klanawa at 1:33 PM on February 2, 2020
For cities, it's because boat freight was the main method until quite recently but you'll find most old cities are mainly built on natural terrace with only the cheaper areas or older areas in the part that floods. Over time people adjust.
For tourist oriented towns it's self explanatory.
For farming communities it's because the best arable, tillable soil is in flood plains. Older towns and settlements have figured out to live on the high areas and farm the low areas. Newer communities, like the American midwest are still figuring that out.
For everything else (residential, retail) it's because they are flat. Developing on flat land is exponentially cheaper.
posted by fshgrl at 1:38 PM on February 2, 2020
For tourist oriented towns it's self explanatory.
For farming communities it's because the best arable, tillable soil is in flood plains. Older towns and settlements have figured out to live on the high areas and farm the low areas. Newer communities, like the American midwest are still figuring that out.
For everything else (residential, retail) it's because they are flat. Developing on flat land is exponentially cheaper.
posted by fshgrl at 1:38 PM on February 2, 2020
We can't predict exactly when any particular floodplain will flood, it's subject to interpretation.
If you're asking if any developers have ever built residential housing in valleys that have been flooded in the past, leaned on local zoning with bribes/influence, taken the profits & bugged off, then the answer is probably maybe yes.
posted by ovvl at 6:02 PM on February 2, 2020
If you're asking if any developers have ever built residential housing in valleys that have been flooded in the past, leaned on local zoning with bribes/influence, taken the profits & bugged off, then the answer is probably maybe yes.
posted by ovvl at 6:02 PM on February 2, 2020
Banks tend to lend more freely where they perceive risk is lower.
Denialism is strong (so is arrogance), I could show you lots of NZ places with new builds in the 3 to 5 metres above sea level range MSL. So a council will (try) and set a moratorium on new builds in say an area below 6m ASL, anmd a developer comes along and sues council. As council coffers are not bottomless they relent - although a recent case here where relented they also told the owner they would recieve no state-sector help when the next floods come.
Food-growing land is undervalued, despite being (AFAIK) more stable as an investment vehicle over 20-30 year timeframes.
In the recent Christchurch quakes large areas subsided due to liquifaction. These areas were known of in the 1980's and were developed around that time too. There were persistent rumours of corruption etc to enable this development but even a Royal Commission didn't manage to find anyone at fault.
posted by unearthed at 6:32 PM on February 2, 2020
Denialism is strong (so is arrogance), I could show you lots of NZ places with new builds in the 3 to 5 metres above sea level range MSL. So a council will (try) and set a moratorium on new builds in say an area below 6m ASL, anmd a developer comes along and sues council. As council coffers are not bottomless they relent - although a recent case here where relented they also told the owner they would recieve no state-sector help when the next floods come.
Food-growing land is undervalued, despite being (AFAIK) more stable as an investment vehicle over 20-30 year timeframes.
In the recent Christchurch quakes large areas subsided due to liquifaction. These areas were known of in the 1980's and were developed around that time too. There were persistent rumours of corruption etc to enable this development but even a Royal Commission didn't manage to find anyone at fault.
posted by unearthed at 6:32 PM on February 2, 2020
Response by poster: Thank you for all the thoughtful answers. in addition, in terms of actual building coastal, how do FEMA construction standards rate?
posted by ebesan at 2:01 PM on February 3, 2020
posted by ebesan at 2:01 PM on February 3, 2020
This thread is closed to new comments.
I wouldn't describe the situation in such absolute terms as you have. Planning is constantly balancing what's referred to as "the takings issue". Politics is responsible for letting folks rebuild in the floodplain (if they are) or to build new projects on land they own already (fairly rare and highly regulated with minimum development requirements). Regulations on single family homes is much more lax than multifamily or commercial/industrial.
posted by humboldt32 at 10:44 AM on February 2, 2020 [1 favorite]