Since most cities are built next to water, the risk of floods threatens more people than any other natural disaster. That risk is increasing as climate change pushes sea levels higher, and though cities are starting to design solutions—witness the flurry of new plans for resilient buildings in New York City after Hurricane Sandy—there’s a need for many more ideas. A recent competition asked architects and other designers to "stormproof" cities for the future.
The ONE Prize competition drew dozens of entries from around the world, including everything from artificial islands to a bridge with giant inflatable buoys to stop surging water. Here are the winning designs.
A network of protective wetlands
After a massive typhoon in 1947, Tokyo built a network of dams, but it still isn’t really prepared for flooding; a similar storm today could affect 2.3 million people and cause $400 billion in losses. Since the government can’t afford to build and maintain more mega-dams, architect Kenya Endo proposed a design that builds barriers around a river using sediment collected from current dams.
"It’s a new type of dam that could interplay with urban design, enrich the ecosystem, as well as store water," Endo says. The barriers would create a network of wetlands that can help bring back native wildlife while protecting the city from floods. The system can also purify the city’s drinking water supply. Unlike a typical concrete dam, it can also create parks where kids can play.
"The proposal goes beyond just stormproofing to think more fully about what a city is," says Maria Aiolova, co-founder of Terreform ONE, the organization that sponsored the award. Endo’s design won first place in the competition, and he plans to continue pursuing the idea.
A new island for Staten Island
In New York City, low-lying Staten Island was one of the places most devastated by Sandy. This design from Cricket Day, one of three second-prize winners in the competition, suggests building a 7.5-mile long barrier island for protection from future superstorms. With a few human interventions, the natural process of sedimentation could be speeded up enough to create the island over the coming decades, while other parts of Staten Island are slowly submerged by rising sea levels.
A reef recycled from shipping containers
Designed to protect Indonesia from tsunamis, this solution from Ben Devereau proposes stacking old shipping containers on the ocean floor. By adding a slight electric charge to the metal containers, the system can stimulate coral growth, building up a barrier that can slow down stormwater. Because the coral can be trained to grow in unique structures, Devereau suggests that it can also be harvested to make "biocrete," a new material that could be used for construction on land.
A giant park along the New York City coastline
This might be the most obvious—and perhaps wisest—solution: Move people and buildings away from land along the coast that's likely to flood. Katherine Rodgers's design includes hundreds of miles of parkland circling Raritan Bay in New York and New Jersey. Urban development would stop far from the shore, and then a series of planted buffers, wetlands, and paths would slow down surging waves.