The plan would entirely revamp the coastline, protecting riverbanks and shorelines.
It's visionary, it's creative and right now there's no money for it, reported CBS2's Marcia Kramer.
De Blasio wants $10 billion to protect the vulnerable Financial District and the South Street Seaport from rising seas and punishing weather events by extending Manhattan island as much as 500 feet into the East River - up to two city blocks.
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"Today we announce a plan unlike anything that has been done before in terms of its scope, in terms of its impact. This is a plan that will protect Lower Manhattan for the remainder of this century," de Blasio said.
Because it's unlike anything that's been done before - landfill pushing out as much as two blocks into the East River - it could face opposition from community groups and environmentalists who have, in the past, blocked municipal projects.
"Are there any environmental concerns: The fish, the snail darter, all these things that have been raised in the past," Kramer asked.
"I'm going to say, Marcia, there's always real environmental issues that have to be grappled with," de Blasio said.
And there's also the question of money: Who exactly is going to pay for it?
The mayor says he's willing to put $10 million in the kitty for engineering studies, but the $10 billion?
"And the way you're going to try the find the $10 billion is?" Kramer asked.
"First, federal dollars," de Blasio said. "Failing that, we're going to work with the community and find some combination of city, state dollars and private development."
"Ten billion dollars? No, too much," one man told Kramer.
"In order to preserve the land, I guess it's a good idea for the land. But in order to preserve the environment with the water and the river, probably not the best," another told Kramer.
"Ten billion dollars?" one woman said. "I do think it's the best way to spend the money."
"Anything that could help to protect this area is worth it, right?" another woman said.
It's unclear what actually gets put up on the new coastline sites. If the city has its way, it would probably be parkland. But if a private developer gets involved, they probably want apartment buildings.
Officials say the project is critical.
The Financial District is not only a key component of the city economy, home to half a million jobs and 90,000 residents, but it is also the nexus of almost all the subway lines.
"We can not afford to bury our head in the sand," de Blasio said.
Another component of the plan, coming with a $500 million price tag, is to fortify most of Lower Manhattan with grassy berms in parks and removable barriers that can be anchored in place as storms approach.
Those steps are necessary, officials say, because six years ago Superstorm Sandy wreaked havoc: Putting 51 square miles under water. Some 17,000 homes were either damaged or destroyed.
The Rockaway peninsula, particularly hard hit by Sandy, has already been reinforced with new sand dunes 20 feet above sea level.
The New York congressional delegation recently secured $615 million for a sea wall to protect Staten Island.
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