Rivers, the largest of which is the Hudson River, which originates in the Adirondacks and flows south to New York Harbor. From the City north to the Federal Dam at Troy, NY, the Hudson River is a tidal estu- ary. Other rivers include the Bronx River and Hutchinson River.

The two major rivers defining the geography of New York City are the Hudson River and the East River. The Hudson River, on the west side of Manhattan, is a true river that flows down from the Adirondack Mountains, separating New York from New Jersey. The East River, however, is technically a tidal strait; it connects the Upper New York Bay to the Long Island Sound and separates Manhattan and the Bronx from Brooklyn and Queens. In 2026, these waterways are more than just geographical markers; they are vital arteries for the NYC Ferry system and the city's ongoing "living shoreline" climate resilience projects. While the Hudson is known for its deep-water shipping lanes and the iconic Palisades, the East River is famous for its powerful currents and the series of historic bridges—including the Brooklyn, Manhattan, and Williamsburg bridges—that define the city's world-renowned skyline.