This map uses point data provided by the NYC Department of Buildings' Active Major Constructions Database to portray new constructions as of March 2021.

Sea level rise predictions were sourced from NYC Opendata Sea Level Rise Maps, detailing the 2050s 500-year Floodplain prediction for New York City.

Neighborhood polygons were drawn in Carto and approximated by the author's consultation of Google Maps, recognizing that neighborhood boundaries are fluid and ever-changing.

Q: What is a 500-year floodplain, exactly?

Sparing technicalities, a 500-year floodplain depicts areas that would be affected by a 500-year flood (a type of flood with a one in 500 chance of occurring in any given year).

Q: Are there any flaws in the "xxx-year floodplain" prediction model?

Definitely; there is a growing literature on this topic. Check this article for a starting point; this article and this article also offer enlightening answers to this question.

Q: Is there a reason why the 500-year floodplain model was chosen as opposed to the 100-year floodplain (a less extreme model)?

This "extreme" choice was made in an attempt to address the concerns mentioned above from critics that view FEMA's floodplain predictions as far too conservative for our constantly accelerating climate reality.