NEW DELHI: The Ganga and Brahmaputra basins are witnessing a record low in snow persistence in the past 23 years, raising concerns about an impending water crisis that could affect the over- 650-million people dependent on the snow-fed river systems. As per latest data, this decline in snow persistence has been consistently observed for three consecutive years.
Seasonal snowmelt is crucial for water availability in the vast stretches drained by the two perennial rivers. It contributes to around 23% of the annual flow, especially in early summer, and nourishes rivers for various purposes including agriculture and hydropower.
According to the latest Snow Update Report of the Hindu Kush Himalaya region, snow persistence – the duration that snow remains on the ground – in the Ganga basin this year has been 24.1% below normal, the lowest in past 23 years.
The current snowmelt deficit may lead to reduced river flow in early summer. In contrast, the basin recorded its highest snow persistence in 2015, when it stood at 30.2% above normal.
The basin had a deficit of 13.6% and 20.4% snow persistence in November 2023 and March 2024 respectively. This year, the deficit has increased to 24.1%. In the past six years, four seasons witnessed a deficit in snow persistence. In 2020 and 2022, the Ganga basin witnessed a snow surplus, 27% and 26.4% above normal respectively.
The consistent decline of snow for the past three years has put the lives of India’s 43% population who reside in the Ganga basin at risk.
Similarly, the Brahmaputra basin has also recorded a consitent dip in snow persistence which fell to its lowest–27.9% below normal–in 2025. The basin had recorded a deficit of 10.7% and 15.7% in snow persistence in November 2023 and March 2024, respectively.