NYC Living: What Qualifies as a Flood Zone?

With the recent impact of Hurricane Irene and the evacuation of portions of Lower Manhattan and Battery Park City, as residents we are all left with many lingering questions. One is forced to ask themselves just what in exactly in New York City qualifies as a "flood zone"?

While it is true that Manhattan is surrounded by water and it is true that some portions of Lower Manhattan in particular are at a very low sea level (5 feet above in some portions) this particular slice of Manhattan is not very susceptible to tides, per se. The southern end of Manhattan is surrounded by Brooklyn, New Jersey, and other barrier islands like Liberty Island, Ellis Island, and Governors Island; but mostly Brooklyn. Even when tides do come in towards the high end, they crest around five and a half feet.

So even at the highest tides for the month and the lowest tide regions of Lower Manhattan you're talking about what amounts to basically at sea level.

With ground at sea level and 20 foot swells, that's a big deal, right? Of course it is. Or it would be for Battery Park City were there any residents living at the street level. It would still take a great deal of swells to get into the enclave that is Battery Park City. When Mayor Mike got on the horn and told Battery Park City they had to evacuate, my first thought was "what for?"

So many of the buildings in Battery Park City are luxury high-rises. Yes they have windows up at that height and yes they do have entrances at the ground level. But the thing about these high rises is that the lobby areas of these buildings is massive in scope. We're talking two or three stories just in the "first floor" which is where guests sign in and where deliveries are made and where other main level building amenities (health club, retail outlets, dry cleaners, etc) would go.

The fact that New York City was largely spared from the brunt of Hurricane Irene, I think, didn't matter in the case of Battery Park City. All the residents could have well stayed in and been just fine. Of course pack a little extra so you don't have to leave the building for the day but really, that's it.

Maybe Bloomberg and company didn't want to have one of the residents of these high rises sue him because they had to walk down stairs to get out of the building with no elevator. That's the only logic I could see for evacuating a building like the Battery Park City properties for an event of a hurricane like Irene.

Sources:

http://www.wnyc.org/articles/wnyc-news/2011/feb/09/climate-change/

http://www.weatherforyou.com/reports/index.php?forecast=tides&alt=tides&locid=475