(Courtesy of the NYPL)
Just like in Venice, and that other Venice in Los Angeles, Manhattan once had canals. The Heere Gracht was a canal that ran down Broad Street into the East River for thirty years, from 1646 to 1676.
Here's some brief background from Hidden Waters (a companion site for the excellent book of the same name):
Prior to colonial settlement, Broad Street was a brook that drained from the Shaape Waytie, or Sheep Pasture. Along the way, a smaller tributary called the Beaver Path linked with the inlet. This was the southernmost interior waterway in Manhattan.
Just as the capital of the Netherlands had a network of canals running through its commercial center, New Amsterdam would as well. In 1646, the colonial government transformed the inlet into the Heere Gracht, Beaver Path became Begijn Gracht and the inlet’s northernmost block was named the Prinzen Gracht, after canals with the same names in Amsterdam.
The canals were wide enough for small boats and soon after New Amsterdam’s handover to the English in 1664, it became an outdoor dump. The colony’s new masters did not care for canals and ordered the Heere Gracht filled in 1676.
There are several maps of the City of New Amsterdam showing the canal (which then turned into what was called Prince Street), as well as another one on a section of Beaver Street (then known as "The Beaver Path").
The most famous is the Castello Plan, created by Jacques Cortelyou in 1660 (which you can view here, and here's a then & now overlay).
This is a redrafted version from 1916, created by by John Wolcott Adams and Isaac Newton Phelps Stokes.
(Courtesy of the NYPL)
Presumably, intersecting Bridge Street was named such for the first bridge once went over the canal (you can see three on that above map). According to this photo in the NYPL's archives, one of these was a fishing bridge:
(Courtesy of the NYPL)
Here's some more on the canals from George Everett Hill and George E. Waring, Jr., circa 1899.
[During the early Dutch settlement] an inlet of the bay, which could be made to do duty as a canal, extended inland for about a quarter of a mile on the line of the present Broad Street. This ditch was the natural outlet for a marshy section of considerable size lying above what soon came to be known as The Beaver Path, now Beaver Street.
By the late 1640s the canals were lined with sheet piling to stabilize both their banks and the narrow streets on either side. The largest canal was the Heere Gracht [Gentleman's Canal], which is now Broad Street from Pearl to Beaver Streets. Its narrower continuation, from Beaver Street to a point just south of Exchange Place, was called the Prinzen Gracht. Both were named, perhaps in jest, after two elegant canals that had recently been built in Amsterdam. The Bever Gracht was a branch canal along what is now Beaver Street from Broadway west to about the present New Street. A drawback of the canals was that they also served as open sewers and stank terribly. The British filled them up in 1676.
Not quite the picturesque scene you get on the Venice canals.
