Nearly six years after the Bloomberg administration proposed the idea of building a counterpart to Battery Park City, the de Blasio administration is poised to argue that new land needs to be created in the East River to protect Lower Manhattan from the threat of climate change.

According to a planning document obtained by Gothamist, the proposal will be part of a coordinated effort to mitigate storm surges and sea level rise downtown. The area considered for new land would be south of the Brooklyn Bridge down to around the Battery, and out to the pier-heads, according to one person who was recently briefed by the city on the plan, and who is not authorized to speak to reporters.

The "Big U" protection system that won a 2014 design competition has since been broken down into separate parts—the East Side Coastal Resiliency project will shore up East 25th Street down to Montgomery Street, while the Lower Manhattan Coastal Resiliency project covers the 0.82 mile stretch of the Two Bridges neighborhood, and the Battery Park City Authority has its own climate change plan in the works. The new land would cover the Seaport area and the Financial District.

New York City has seen its sea level rise one foot since 1900, and scientists say that by 2100, it could rise as much as six feet due to climate change. By 2080, the city may feel like Jonesboro, Arkansas.

Mayor Bloomberg's proposal to build a "multi-purpose levee with raised edge elevations" from Pier 35 to the Battery Maritime Building was part of a 430-page report by the Special Initiative for Rebuilding and Resiliency (SIRR) that was released in June of 2013 to help the city meet the urgent challenges posed by climate change after Superstorm Sandy. A press release stated that "Seaport City" would be "a new area for both residential and commercial development."

"The precedent that led us to think about this in the first place is Battery Park City, because if you look at the flooding that came with Sandy, Battery Park City actually served as a barrier, and prevented much of the water that was coming up the Hudson from the storm from penetrating Lower Manhattan," said Seth Pinsky, Bloomberg's SIRR director at the time.

The buildings on Battery Park City are built seven feet higher than their counterparts on West Street, and the while the neighborhood saw some flooding, very little damage was done compared to the rest of Lower Manhattan.

"In areas where the real estate values are high and the demand for development is high I continue to believe that using that development demand to help fund the creation, not just of barriers that protect inland areas, but also new recreational facilities and new amenities, makes a lot of sense from a whole lot of perspectives," said Pinsky, who is now an executive vice president at the real estate developer RXR Realty.

The person briefed on the plan said that while it is not clear whether development would be allowed on the new land, "it’s safe to say that this is going to have to be a public-private partnership," given the enormous costs involved. Still, that person rejected comparisons to Bloomberg's project.

"Seaport City was primarily for economic development. This is going to be a resiliency measure first and foremost," the source told Gothamist. "The reality is that this is the only way to protect many billions of dollars of private and public property, and this option is by far the most expensive one to do."

The New York City Economic Development Corporation referred questions on the plan to Phil Ortiz, a spokesperson for the Mayor's Office of Recovery and Resiliency. Ortiz did not confirm or deny the proposal.

"Rising sea levels are an existential threat to our city. It’s no secret that we are working hard to develop different ways to address the challenge," Ortiz said in a statement. "There are lots of ideas out there and many different versions of potential proposals for this area—many of which are significantly outdated, or no longer under consideration. When we select a final approach for community consideration, we’ll certainly be making it public."

Several experts said they couldn't think of many recent examples of large quantities of land land being created in the sea that are designed to act as both climate barriers and places for development.

"My perspective, is that you need to evaluate everything," says William Solecki, a professor at Hunter College who studies urban environmental change and resilience, and who co-chairs on New York City's Panel on Climate Change [NPCC].

"That’s a thread, a challenge, the city has faced for a long time: how do you balance out the ecological interests or the other sort of demands that the waterfront and the coastline of the city enable, while at the same time meeting the needs of the city’s residents and economy?"

Ted Steinberg, an environmental historian at Case Western Reserve University, said the idea "sounds like Seaport City. New wine in an old bottle, so to speak."

Steinberg, who is the author of Gotham Unbound, an ecological history of New York, noted that New Yorkers have a long history of adding land to their city. "That may have worked back in the 1700s," Steinberg said. "Now several hundred years later, to be doing the same thing you’ve been doing hundreds and hundreds of years ago, doesn’t seem to me to be particularly original, creative, or wise, under the circumstances."

He added, "The scientific community is telling us we’re living in a world of natural limits and human vulnerability, and people don’t want to believe that, and people in authority don’t want to believe that, and real estate in New York doesn’t want to believe that. But frankly, that’s what the science says... Seventeen percent of the city was flooded during [Superstorm Sandy] and much of that land is land that was reclaimed from the sea."

The de Blasio administration is expected to announce the new measures to fight climate change in the coming weeks.

Catherine McVay Hughes, a Financial District resident who was the chair of Manhattan Community Board 1 during Sandy, offered a piece of advice to the city no matter what plan is chosen.

"There are a lot of questions, and it's very important to involve the community early in the planning process."