As the climate changes, sea levels will rise and weather will become more extreme. That presents a particular risk for coastal cities and low-lying regions. New York got advance warning of that risk with Hurricane Sandy – exactly the kind of storm that will become more likely in a warming world.
So New York is preparing, and plans are being unveiled for making the city more resilient. One intriguing proposal that recently got funding is The Big U. It’s a bold plan to reconstruct the waterfront with a series of storm defences along ten miles of coastline. In the process, large areas of public space will be created, making them into an amenity and community asset rather than just a flood barrier.
The Big U is based around a series of barriers that can contain and disperse floodwater. The largest is a ‘bridging berm’ that runs along the front, enclosing Battery Park. It’s an embankment with a cycle path on the outer side and a footpath along the top. ‘Green infrastructure’ features prominently – trees, rain gardens, and street plantings. These will “absorb and clean stormwater, cool the city, reduce air pollution, store carbon, buffer noise, enhance recreational activities, improve mental health, and provide green jobs.’ Nice.
The project makes creative use of existing infrastructure, perhaps most impressively with the flip-down barriers proposed along the elevated highways. Large panels would be fitted to the concrete sides of the flyover. In storm conditions they would drop down to turn the whole highway into a wall. The underside of the panels would be decorated by local artists and illuminated.
Like Rotterdam’s ‘water plazas’, landscaped areas are designed to flood incrementally, turning smaller floods into different leisure opportunities. A long snaking concrete lip called ‘the big bench’ runs through one area, forming a swimming pool in one place, a raised platform for yoga or Tai Chi in another, and a variety of seating – quiet areas for reading, social ones for picnics, or little performance spaces. All of this has been planned with extensive community involvement, and residents are excited about the possibilities.
New York has a lot to lose – 200,000 people live along the ten miles of Manhattan’s coastline. Roughly half of those are lower income residents along the East River, often elderly or vulnerable. On the other side is the financial district, which Hurricane Sandy disrupted for a week. The cost of future storms will be both human and economic, and the city is right to prepare. Other coastal cities should do likewise, and could learn a lot from New York’s community led resilience-building.