NYC building seawall amid vulnerability to climate change

NEW YORK • After major storms highlighted New York's weaknesses in the face of climate change, the city is erecting a US$1.45 billion (S$2 billion) system of walls and floodgates to protect it from rising sea levels.

Superstorm Sandy in 2012 was the trigger for establishing the East Coast Resiliency Project, running 4km along the shoreline of Lower Manhattan. Hurricane Ida, which ravaged parts of the city this year, added further urgency.

During Sandy, which killed 44 city residents while impacting 110,000 more and leaving US$19 billion of damage, water levels rose more than 2.4m.

The completed wall will reach as high as 5m, said New York's acting Design and Construction Commissioner Tom Foley. The project will include gates to prevent water from seeping into Manhattan, home of the densest population in the United States.

The wall between 20th and 23rd streets is already up, an area where the East River and residential housing are at their narrowest.

Further down, where terrain allows, the project will include a hilly park as a protective wall, as well as a dock, an esplanade, bicycle lanes, benches and garden areas.

The city will also plant some 1,800 trees, and an additional 1,000 in the neighbourhoods, said Ms Sara Nielsen of the New York City Parks Department.

And a new underground drainage system will improve the sewage network's capacity, while the construction of a power substation should help prevent a days-long power loss such as one that happened during Sandy.

That major 2012 superstorm proved to be one of the worst to hit the US this century, along with Hurricane Katrina in 2005, which devastated New Orleans, and Hurricane Harvey, which lashed Houston in 2017.

But the project is far from enough: New York's approximately 800km of coastline faces forecasts of sea-level rise of more than 60cm by 2050 and nearly 1.8m by the end of the century.

Ms Jainey Bavishi, who directs the Mayor's Office of Climate Resilience, said the city is investing in a "multi-layered strategy".

"We are building coastal protections where possible to keep the water out - but we also recognise that we're not going to be able to keep the water out in all places," she said, explaining that the protections are built to be adaptable.

"So if the projections for sea-level rise and storm surge get worse than what we believe they are now, we can add elevation to the wall to add further protection."

Many buildings in Manhattan, along with crucial infrastructure, are also being reinforced, Ms Bavishi said, with construction limited in high-risk areas, and collaboration with residents and small businesses to minimise the impact of extreme weather events.

The East Coast Resiliency Project, meant to be completed by 2026, is just one component of a larger project announced in 2013, when the city revealed a nearly US$20 billion plan aimed at "climate resilience".

But that price tag is just a "down payment", Ms Bavishi said. "Resiliency is a process, not an outcome."

AGENCE FRANCE-PRESSE