Parts of New York City are submerged under 13 feet of water, but help is on the way: As we speak, a specialized unit called the "National Unwatering SWAT Team" is en route to Gotham. Ever heard of 'em?

During a press conference in Manhattan this morning, New York Gov. Andrew Cuomo raised eyebrows with his mention of the group sent by the U.S. Army Corps of Engineers. "A National Unwatering SWAT team is on its way to New York and we need them very badly," said Cuomo, seeming "slightly amused by the name" according to one reporter. What is this "unwatering" process and what in the blazes is an "Unwatering SWAT Team?" We asked Rodney Delp, chief of emergency management at the Army Corps of Engineer's Rock Island District in Illinois, where the SWAT team is typically stationed. We started with the basics: What's unwatering?

"It's just removing water from places it's not supposed to be," he said plainly. Duh! While his answer was simple, he said the task ahead of the Rock Island District's unwatering team was not. 

The team of four expert engineers left for New York City this afternoon and are expected to arrive between 4 p.m. and 5 p.m. Eastern Time. Delp said they are the finest unwatering experts in the country, given their experience in dewatering the inundated areas of New Orleans after Hurricane Katrina. "They're subject experts," he said. "They can't do all of the work themselves but they can advise the other people in New York." 

The team's tools consist of trailer-mounted trash pumps with discharge pipes 8 to 16 inches in diameter. The engine-driven self-priming pumps can pass water and even golf ball-sized debris. And if the task is too big, they can resort to less mobile pumps with discharge pipes ranging from 16 to 40 inches. The size of the pump depends on the scale of the problem. Delp said a 30-foot hole filled with water is one thing, but if that 30 foot hole is filled with water and leads to a whole subway system that stretches for miles under ground, it's a much bigger effort.

Then there's the issue of what to do with the water once you've moved it out of that hole. "You don't want to just dump it in the nearest gutter," he said. "You have to find out how far horizontally you want to pump it," in order for the water to wind up back in the ocean.

Disaster experts might be familiar with the term "dewatering," but it's slightly different then the term "unwatering." (To the right is a dewatering pump being used in Italy in 2011.) "Unwatering is removing water from a place where it's never supposed to be," he said. In New York City with its flooded tunnels and subway systems, there's a lot of that going on. Dewatering, by comparison, involves the removal of water where it's designed to be but isn't always wanted, like a levee. Suffice it to say, there's going to be a lot of unwatering going on by this four-person team. One of the more daunting tasks he mentioned was the basement of the World Trade Center. "It's 7 stories deep," he said. God speed, unwatering SWAT team! God speed.