By the time New York celebrates its 400th anniversary in 2025, one million more people will be nestled amongst its already cramped streets. Other cities around the world are dealing with density in creative ways; Hamburg is expanding into its waterways with the first of a series of planned houseboat communities. Now New York may be making more of its own waterways with a new proposal developed by a group of Columbia architecture and real estate grad students. Called "The Present Future of New York City," the plan seeks to grow land from Governor's Island, eventually connecting it to Manhattan's southernmost point.

How do you grow land, you may be asking? The students researching the idea found that the Army Corps of Engineers currently pays to ship out tons of dredged muck from the waterways around New York City. So the students thought, why not reuse all that waste to create a sixth borough instead? Yeah, it sounds like a stretch, not only of the imagination but of engineering. How can you turn a bunch of sludge into a livable area, a place where you can actually build? The first step, apparently, is to take out of commission subway cars, drop them into the river and cover them with landfill. If this sounds crazy you should know that New York regularly dumps outdated subway cars into the Atlantic Ocean, simply because they have nowhere else to dispose of them. But instead of trashing the cars, we might very well be able to use them to our benefit, recycling them into the slow expansion of an 88-100 million square foot land mass, a borough they're tentatively calling Lo-Lo Ma.But that's not even the most exciting part. All the money the city would save on marine trash disposal can be redirected into building up the area. According to the proposal, "depending on the density of development, the value of the new land created in Lo-Lo Ma would pay for the costs of developing this new neighborhood, while also allowing for investment in other infrastructural projects." This means that Lo-Lo Ma could effectively pay for itself. It gets a little complicated, but basically the more they develop this land mass, the more the city saves on having to find a way to dispose of it as trash. By 2035 it's possible that enough land mass would be in place to build a bridge from Red Hook and extend seven subway lines. The proposal also includes 40% affordable housing, a waste-to-energy plant and a field of wind turbines.

The students will begin presenting their plan to city officials and engineers later this month. Keep your fingers crossed!