The plan provides for the potential evacuation of up to three million residents and shelter for more than 600,000 people in the worst-case scenario of a major hurricane strike.

The fruit of a nine-month review, it also included lessons learned from the disaster of Hurricane Katrina, such as provisions for individuals with limited mobility and other special needs, as well as hospitals and nursing homes.

"In the event of a coastal emergency, we have to be fully prepared to respond to the needs of residents, particularly those in low-lying areas, to ensure that we leave no one behind," said Mayor Michael Bloomberg.

New York City is particularly vulnerable to storm surge due to a geographic characteristic called the "New York bight" -- a sharp bend in the Atlantic coastline where New York and New Jersey meet.

The bight amplifies the effects of a storm surge and can create severe flooding in coastal areas, particularly when the storm tide coincides with normal high tides.

The New York area has not experienced a hurricane since 1985, and the last direct hit on Manhattan was way back in the 1800s.

But midway through a roughly 25-year cycle of warm waters in the Atlantic Ocean, forecasters say the northeast US coast is statistically overdue for a hurricane visit.

According to a recent report in the New Scientist magazine, the storm surge from a major hurricane making landfall close to the city could raise local sea levels by as much as eight meters (25 feet).

That scenario could result in lower Manhattan, including Wall Street, being swamped, along with parts of Brooklyn and Jersey City, New Jersey.

In total, more than 250 square kilometers (95 square miles) might be affected, causing the evacuation of 2.2 million people from New York City alone.

Related Links
NYC Office of Emergency Management