The recent floods in Nepal have brought to light a critical concern for India: the intricate relationship between the two countries' shared river systems. While it's a common misconception that Nepal "releases" water into India, the reality is far more complex. Nepal's rainfall significantly influences the timing and magnitude of flood peaks reaching India, but the severity of flooding depends on a multitude of factors on the Indian side as well.
The Kosi disaster of 2008 serves as a stark reminder of this interdependence. Despite carrying only a fraction of its carrying capacity, the river caused catastrophic flooding in Bihar due to the failure of an embankment in Nepal. This highlights the structural vulnerabilities rather than the hydrological aspects of the flood.
India's vulnerability extends beyond Bihar. Eastern Uttar Pradesh, for instance, is regularly affected by the Ghaghara, Rapti, and Gandak rivers. The Mahakali-Sharda rivers in Uttarakhand and the Mechi and Mahananda rivers in North Bengal also contribute to the risk. The scale of the problem is immense, with Bihar bearing the greatest burden, followed by Uttar Pradesh, which is often overlooked.
The complexity of the situation is further compounded by the fact that the severity of flooding in India is determined by a delicate interplay of factors. These include the volume of rain on the Indian side, the level of the Ganges, the integrity of embankments and barrages, and blocked drainage from roads, railways, and settlements on the floodplain. The peak flow at the border is largely determined by rainfall in Nepal, but the actual flooding is influenced by conditions in India.
The 2008 Kosi disaster underscores this point. The breach in the embankment was the primary cause, not an exceptional flood. This highlights the importance of structural maintenance and early warning systems. However, India's ability to receive timely warnings from Nepal is limited by gaps in real-time monitoring, forecasting models, and information sharing.
The misconception that Nepal "releases" water into India is a simplification. Nepal's main storage dam, Kulekhani, holds a negligible amount of water, and the Kosi and Gandak barrages are operated by India. The flooding in north Bihar and eastern UP is primarily caused by rain in Nepal, but the timing and size of flood peaks are determined by Nepal's rainfall.
The real concern for India lies in the Himalayas. The recent Nepal disaster is reminiscent of catastrophic events like the Chamoli and Dharali disasters in Uttarakhand. These incidents involve the sudden combination of water, rock, ice, and sediment, resulting in high-energy slurries that can destroy everything in their path. Climate change exacerbates the situation by intensifying rainfall and increasing high-mountain hazards.
In conclusion, the floods in Nepal serve as a warning for India, but it is not a simple matter of blame. The solution lies in better shared data, forecasting, and river management. India must address its structural vulnerabilities and collaborate with Nepal to enhance early warning systems and monitoring capabilities. The complex relationship between the two countries' river systems demands a comprehensive approach to mitigate the risks and ensure the safety of both nations.
