Remember how strange it was to watch the East River transform Manhattan into the set of Waterworld during Hurricane Sandy? Well, there's a good chance we'll be reliving that magical time and time again in the oncoming future, thanks to rising storm tides in the New York Harbor—a new study says the city's surrounding waters have risen by nearly two and a half feet since the mid-1800s, and the Harbor is 20 times more likely to flood now. Not that this has anything to do with human destruction of the Earth, no sirree, nothing to see here.

The study, which was accepted for publication in the Geophysical Research Letters journal, doesn't tell us anything we didn't already suspect. According to the data, a major “10-year” storm—a storm with a 10 percent chance of happening in a given year—hitting New York City today will cause bigger storm tides and far more damage than that same storm would have caused nearly two centuries ago.

More frighteningly, researchers noted that the Harbor waters are more likely to push over the Lower Manhattan seawall once every four to 5 years, as opposed to once every 100 to 400 years in the 1800s. So now, there's a 20 to 25 percent chance that a storm, perhaps even one less ferocious than Sandy, may cause Manhattan to flood, turning the city into a soupy, powerless, dangerous mess.

The study's lead author, Portland State University researcher Stefan Talke, told Mashable that rising sea levels aren't the only cause for concern: the city's wetlands have depleted by about 85 percent since the 1800s, the Lower New York Bay's shipping channel has deepened by about 50 percent to accommodate cruise ships, and other manmade changes to the area will make a storm flood all the more devastating.

There have been proposals to keep the city from getting consumed by its surrounding waters, like adding hurricane fortifications to Lower Manhattan and parts of Brooklyn, and installing movable storm gates in the Harbor, not to mention former mayor Michael Bloomberg's $20 billion "Seaport City" plan. Until then, we're keeping our canoe lashed to the roof.