27 Jan 2024

The BIG U - defending Manhattan from future floods

From Saturday Morning, 9:35 am on 27 January 2024
Rendered image of The Dryline (BIG U)

The Dryline (BIG U) Photo: supplied

When Hurricane Sandy hit the east coast of the US in 2012 New York City was particularly badly hit, suffering major flooding and US$20 billion in damage.

Part of the government's response was to fund resiliency projects to protect the Manhattan coastline against future flooding.

On of the proposals funded was The Dryline (BIG U). The 12 km-long infrastructural barrier incorporates public space with the high-water barrier doubling as parks. 

New York-based architect Kai-Uwe Bergmann, who has contributed to BIG U, told Saturday Morning that the city has about 500 miles of coastline.

"That's a lot of coastal exposure and you're looking at ... the idea of rising sea levels from the polar ice caps melting, you're looking at wind forces movement of water, and you're looking at low lying areas that may have been infilled over time. So water basically goes back to where it wants to be.

"A street like Canal Street ... it was at one time an actual canal therefore it's lower lying than the streets around it and Canal Street flooded."

He said solutions to flooding can either store the water or act like a sponge.

"The BIG U is this idea of actually creating much more green space, play space, things that people really, really support and at the same time these places protect you, they make sure that you stay dry and they have this side benefit."

Bergmann said the team had to think very holistically about the design of the structure and considered things like the differences between a flood at high tide and a flood at low tide.

They held hundreds of meetings with local communities, businesses and residents to hear what their concerns were and offered 20-year, 50-year and 100-year solutions with different price tags.

Projects like this needed to live through multiple administrations to be successful, he said.

"No matter who's in the office, it is their project because this is an important project for the citizens of New York."

He pointed to Central Park as an example.

"A hundred and fifty years ago, that was a project that probably also took multiple administrations to actually realise ... the outcome is one of the most fabulous places on the planet.

"We are creating our generation's version of Central Park, only it's doing one more thing than providing recreation, it's also creating protection."

Bergmann said New York was not alone in its issues with flooding and this was a problem that cities around the world were coming to grips with.

He is a keynote speaker at the "in:situ" architecture conference in Tāmaki Makaurau on 21 February.