Photo: Daily Mail

Growing your own house may seem like a new idea, but what about growing pieces of functional infrastructure? That’s exactly what the locals of Nongriat in Meghalaya, India have been doing for the past 500 years. In that time, they’ve grown bridges over one hundred feet in length and strong enough to support the weight of more than 50 people. There are even “double decker” bridges! More after the jump!

The fifteen meters of annual rainfall of the Cherrapunji region–a figure aggrandized by frequent flash floods–accelerate the flow of its rivers and streams, the fierceness and destructive power of which few wooden or steel bridges could withstand. Transport across the region’s numerous water channels is necessary, whether to return to one’s dwelling after fishing or clothes washing or to escape the dangers of one place to move to another. But how?

The locals’ answer lie in the sloping hills hugging the contour of the water channels, where a species of rubber tree flourishes. From the upper trunk of the ficus elastica, secondary roots grow outwards with great profuseness. The tribes people realized half a millenia ago that they could use these roots to forge a pass across the water below, using hollowed out betel nut trunks to guide the direction of the roots’ growth.

Photo: Daily Mail

Once the roots make their way across the water to the opposite bank, they take hold. Here, they continue to grow and strengthen, not only stabilizing the bridge platform, but also reinforcing the bank walls. The full cycle of bridge-growing may take ten to fifteen years to complete, necessitating the locals’ arboricultural knowledge to be passed on from older to younger generations, who will, perhaps, personally continue the former’s work.

Photo: flickr user Vanlal

Photo: flickr user Vanlal

by Samuel Medina

posted in Video news

tagged bridge design, cherrapunji, engineering, green architecture, india, infrastructure, Meghalaya, roots, sustainable architecture, trees

more articles by Samuel Medina