Through a Narrow Path

An engineering folly unfolds over a week-long journey along Bihar's Kosi river, a tempestuous tributary of the Ganga.

- Archana Yadav

I STAND OVER the Kosi barrage in Nepal that squeezes the river to a kilometre’s width as if between two fingers, just before it enters Bihar. On one side, a few fishermen are catching fish in its slaty water. The fish, no bigger than the size of a palm, twist and flip as they are removed from the fine net and tossed into the boat. On the other side, boatmen are collecting wood that has drifted there from the forested hills of the Himalayas.

It gives me a kind of thrill to be aware that the water flowing under my feet carries snowmelt from peaks as high as Mount Everest and Khangchendzonga. The Kosi originates in Tibet. Even before the Himalayas rose 70 million years ago, the Kosi’s tributaries flowed into the prehistoric Tethys Sea. The Himalayas gave it a catchment of amazing diversity. Ajaya Dixit, a water expert in Nepal, explains it thus: “As the crow flies, about 150 km from north to south the catchment covers six geological and climatic belts varying in altitude from 8,000 m to just 95 m: the Tibetan plateau, the high Himalaya, the midland hills, the Mahabharat range, the Siwalik range and the Terai ... Eight peaks over 8,000 m high, including Sagarmatha [Everest], are in the Kosi catchment as are 36 glaciers and 296 glacier lakes.”

It is a large catchment and the hills are mostly loose soil. When it rains this soil is easily eroded and quickly carried down steep slopes. As the river debouches from the foothills, 50 km upstream of the barrage, it spreads the silt and sand in the shape of a huge fan. This megafan, about 180 km long and 150 km wide, is the floodplain I intend to traverse along the Kosi in north-east Bihar.

'Wrinkles on the forehead of pleasure'