Hudson River Secrets-1 WTC-Lower Manhattan-NYC-2

With over five hundred miles of coastline, it’s no surprise that New York City is directly shaped by the waterways that surround it. While the Hudson River has long served as a working waterfront, home to warehouses, businesses and passing freights, it’s also an iconic city fixture in and of itself. Much like the various bridges it flows under, the river is a sight to behold — and it also happens to hold many secrets.

1. The Hudson River is Not Just a River

In-the-know New Yorkers like to point that the Hudson River is both a river and an estuary, meaning the waters come in from multiple sources, including salt water from the sea. As Leslie Day, author of River: Living on the Hudson – A Natural History and is a specialist on the Hudson River, “A river is a body of fresh water that flows from the mountains to the sea – which the Hudson does. An estuary is ‘an arm of the sea’ and at incoming tide flows into a river basin. So the Hudson is a ‘river that flows two ways’ – a tidal river from its estuary that brings ocean water up the river basin, and a freshwater river that flows from the mountains to the ocean. Thus we have 2 high tides and 2 low tides every day.”

The New York State Department of Environmental Conservation even goes so far as to say that the river actually “feels the ocean’s tidal pulse all the way to Troy,” 153 miles from the New York Harbor, and almost half the length of the 315 mile river. Rising tides will push the current towards Troy, and falling tide will move the water back towards the harbor. Every 24 hours, there will usually be two high tides and two low tides. When the water is frozen over during the winter, the ice will also drift both ways (south or north). For your entertainment purposes, here’s a video of ice on the Hudson River being broken to clear a channel for barges.