In the past two decades, the world’s ten worst floods have done more than a hundred and sixty-five billion dollars’ worth of damage and driven more than a billion people from their homes. In the summer of 2017 alone, Hurricane Harvey dumped more than fifty inches of rain over Texas, a monster monsoon season damaged more than eight hundred thousand homes in India, and flash floods and mudslides claimed at least five hundred lives in Sierra Leone. Water Institute member, Elizabeth English, spoke to The New Yorker about her work with amphibious housing as a means to provide innovative, sustainable and low-cost flood mitigation strategies
In August 2005, after Hurricane Katrina, Waterloo Architecture professor Elizabeth English began looking at the implications of all the flood damage and the social disruption that it caused. She was extremely unhappy about the cultural insensitivity of the solutions that were being proposed, such as permanently elevating houses – lifting them up onto raised foundations or stilts.
"People didn’t want to move up,” English said. “And it visually thoroughly destroyed the neighborhoods. There had to be a better way.”
She discovered that better way in another perpetually sodden locale—the Netherlands, where developers were building a cluster of amphibious homes in a flood-prone region along the Maas River. The houses sat on hollow concrete boxes attached to large steel pillars. During a flood, the boxes would function like the hull of a ship, providing buoyancy. As the waters rose, the buildings would rise, too, sliding up the pillars and floating on the water’s surface. When the waters receded, the houses would descend to their original positions.
It was an elegant solution, English thought, but not quite what she was looking for. Building a hollow foundation is a major construction project; English wanted to give New Orleanians an easy and inexpensive way to modify their existing homes. In 2006, she founded a nonprofit called the Buoyant Foundation Project and began working with a group of architecture and engineering students to devise a method for retrofitting local homes with amphibious foundations. A typical New Orleans shotgun house sits slightly above the ground, resting atop short piers; the researchers could, they thought, fasten a steel frame to the underside of a house and affix a set of foam buoyancy blocks. Then they could sink posts into the ground and attach them to the corners of the frame, allowing the house to rise up off the piers without floating down the street.
Illustration by Seb Agresti, The New Yorker
English and her students built a full-scale prototype of the system, and in the summer of 2007 they put it to the test. The system was simple and cheap; it could be installed by two reasonably handy people without heavy equipment for between ten and forty dollars a square foot. It left a building’s appearance and structure almost unchanged, and it was more resilient than permanent elevation, which can cost two or three times as much and make a building more susceptible to wind damage.
“This is not a one-size-fits-all solution,” English said, noting that the system would not provide adequate protection against high-speed waves. “But it’s an excellent solution for some circumstances.”
English became so enamoured of the approach that she began to think beyond the bayou. In the past decade, she and her colleagues at the Buoyant Foundation Project have designed amphibious-housing prototypes for low-income, flood-threatened regions in Nicaragua and Jamaica. They have also consulted with indigenous communities in Canada and Louisiana.
English is currently working with the National Research Council Canada on a project to reduce flood vulnerability in First Nations communities in anticipation of increased flood risk due to climate change, as well as with the international Global Resilience Partnership on a similar concept to increase the flood resilience of rice farmers in Vietnam’s Mekong Delta.