2006 New York Code - Datum.

 
    §  27-158  Datum.  All  elevations  on  plans shall be referred to the
  United States coast and geodetic survey mean sea level datum of nineteen
  hundred  twenty-nine  (national  geodetic  vertical  datum,  NGVD),   as
  provided  in  section  26-208  of chapter one of title twenty-six of the
  administrative code, as amended. The following table shall  be  used  to
  convert NGVD to borough datum elevations:
 
    Location Add to NGVD to obtain borough datum elevation in feet:
 
                          Bronx             +2.608
                          Brooklyn          +2.547
                          Manhattan         +2.752
                          Queens            +2.725
                          Staten Island     +3.192