Hypothetical Flooding to Restore 1660 Manhattan Contours?

As recently discussed here and there, a group of scientists have tried to predict how more frequent flooding--induced by global climate change--could affect New York City.

An interesting facet of this conceptual floodmap from the Union of Concerned Scientists is the way it uncannily traces the boundaries of 400 years' worth of landfill on both East and West sides of lower Manhattan. In the 1600s, the East River lapped the edge of Pearl Street, while the Hudson approached the town's high road, Broadway.

The floodmap depicts the submersion of areas built upon landfill, such as Battery Park, South Ferry, and South Street Seaport. If the waters rise, would the Dutch reclaim New Amsterdam and reconstruct the "Gentleman's Canal" along Broad Street?

More:
Gothamist: Map of the Day: If NYC Flooded Every 10 Years...
PBS: New York: A Documentary Film
Union of Concerned Scientists
City Room: Dire Climate Forecast Includes the 100-Year Flood, Once a Decade.
Dutch Days: Peter Stuyvesant's Ghost