How to make a city waterproof

By Giovanna Dunmall

One evening in March, a pale-blue layer of light began spreading across the plaza outside the United Nations headquarters in New York. Emanating from banks of leds, it appeared to undulate like the surface of the sea high above the heads of passing pedestrians. The effect may have been ethereal but the warning was all too real: the light submerged the plaza to the same depth that water may do if nothing is done to control rising sea levels.

Called “Waterlicht” (Waterlight), the installation was the work of Daan Roosegaarde, a Dutch artist; New York was just one stop on a tour of global cities. Roosegaarde’s intention is to focus people’s minds on the prospect of a watery future. “Above all it gets people who might never do so talking about water and global warming,” he says. Often the conversation turns to keeping water out. But increasingly urban planners and designers are taking their cues from Rotterdam, the city where Roosegaarde lives and works: they are working out how to let water in.