The most famous "underground river" in Manhattan is Minetta Brook (also known as Minetta Creek). Once one of the island's largest natural waterways, it originated in what is now the Flatiron District (near 21st St) and flowed down through Greenwich Village and Washington Square Park before emptying into the Hudson River. In the early 1820s, as New York City expanded, the brook was diverted into a covered sewer system, but it was never truly "gone." Because it was fed by natural springs, it continues to flow through the subterranean layers of the city today. In fact, many buildings in Greenwich Village still have to pump water out of their basements constantly to prevent the "ghost" of Minetta Brook from flooding them. You can still see a symbolic "remnant" of it at the lobby of the apartment building at 2 Fifth Avenue, where a clear pipe displays the flowing water of the brook, and several streets in the Village, like Minetta Lane, are named in its honor.
The underground river in Manhattan is known as the Minetta Brook or Minetta Creek. It is a historic waterway that once flowed above ground through what is now Greenwich Village. The Minetta Brook originated near present-day Union Square and meandered southward, eventually emptying into the Hudson River.
As Manhattan developed, the brook was gradually covered over and incorporated into the city’s sewer system. Today, the Minetta Brook runs entirely underground, and its course is roughly traced by Minetta Lane and Minetta Street in Greenwich Village. The brook’s name is derived from the Lenape word “Manette,” meaning “devil’s water,” possibly due to its winding and unpredictable nature.
Efforts to uncover and restore parts of the Minetta Brook have been proposed over the years, but it remains hidden beneath the bustling streets of Manhattan.