- Nepal's devastating floods have exposed a risk that does not stop at its borders. India and Nepal share the rivers that rise in the Himalayas, but the relationship between a flood in Nepal and a disaster in India is more complicated than a simple story of water flowing downstream, say experts.
- Nepal's floods are a warning for India - not simply because water flows south across the border, but because the two countries share a vast and increasingly volatile Himalayan river system.
- Bihar is by far the most exposed Indian state, with roughly three-quarters of north Bihar officially classified as flood-prone. Almost all the major rivers that flood the state originate in Nepal, with the Kosi - the 'sorrow of Bihar' - the most notorious, followed by the Gandak, Bagmati and Kamala.
- The risk extends beyond Bihar: Eastern Uttar Pradesh is vulnerable to the Ghaghara, Rapti and Gandak rivers, with districts like Gorakhpur, Bahraich, Lakhimpur Kheri and Shravasti regularly affected. Uttarakhand shares the Mahakali-Sharda rivers, and North Bengal receives the Mechi and Mahananda.
- Nepal has more than 6,000 rivers and streams, most draining south into India and the Ganges. Three major systems dominate: the Kosi in the east, the Gandaki (Gandak in India) in the centre and the Karnali (Ghaghara in India) in the west, with the Mahakali (Sharda) along the western border.
- Seven to nine major rivers flow from Nepal into the Indian plains, and they are responsible for flooding in India, according to Manish Shrestha, a hydrologist at the International Centre for Integrated Mountain Development (ICIMOD).
Nepal's recent floods serve as a stark warning for India, particularly Bihar, which is highly vulnerable to flooding from shared Himalayan rivers. Experts emphasize that the relationship between Nepal's floods and disasters in India is complex, as these rivers do not respect borders.23
Nepal is home to over 6,000 rivers, with seven to nine major rivers flowing into India, significantly impacting states like Bihar, where three-quarters of north Bihar is classified as flood-prone. The Kosi River, infamously known as the "sorrow of Bihar", is the most notorious for causing floods, followed by the Gandak, Bagmati, and Kamala rivers.45
The risk extends beyond Bihar, affecting eastern Uttar Pradesh and Uttarakhand, where rivers like the Ghaghara and Mahakali pose threats. Districts such as Gorakhpur and Bahraich frequently experience flooding due to these shared water systems.
The 2008 Kosi disaster exemplifies the dangers; nearly 400 people died when the Kosi breached an embankment in Nepal, despite the river carrying only a fraction of its capacity. This incident underscores the need for better management of these shared resources to prevent future catastrophes.
Manish Shrestha, a hydrologist at ICIMOD, notes that the relationship between Nepal's floods and Indian disasters is intricate, necessitating collaborative efforts to mitigate risks across borders.6
“Bihar is the most exposed Indian state, with roughly three-quarters of north Bihar classified as flood-prone, and the Kosi river is the most notorious. Hydrologist Manish Shrestha of ICIMOD notes that seven to nine major rivers flowing from Nepal are responsible for flooding in India.”
bbc.com
