Kathmandu, Apr 24: Ganga basin is among the 12 showing above-normal snow persistence in 2026 when overall snow cover across the Hindu Kush Himalaya was below-normal for the fourth consecutive year and even broke last year’s record-low deficit, a report said Friday.
The Hindu Kush Himalaya (HKH) Snow Update by the International Centre for Integrated Mountain Development (ICIMOD) is an annual report that monitors seasonal snow anomalies in the HKH region and offers an assessment of snow persistence between the winter months of November and March.
Between 2003 and 2026, the HKH region experienced 14 winters with below-normal snow persistence, emerging as a recurrent pattern, particularly with increasing frequency and intensity in the recent years.
“This year, 2026, is the fourth consecutive year of below-normal snow persistence, with snow persistence declining further to 27.8 per cent below average and even breaking last year’s record low deficit of 23.6 per cent,” the HKH Snow Update 2026 said.
“The persistent decline signals a systemic collapse of seasonal snow reserves across the world’s highest mountain range, posing an immediate and escalating threat to water security for nearly two billion people who depend on the 12 major river basins originating in the HKH,” it said.
ICIMOD defines snow persistence as the fraction of time snow remains on the ground after snowfall.
Ten of those basins now have below-normal snow persistence. The Mekong, Tarim, and Tibetan Plateau have recorded their lowest levels in 24 years of monitoring, the ICIMOD report said.
Only two basins recorded above-normal snow persistence: the Ganges at plus 16.3 per cent and the Irrawaddy at plus 21.8 per cent, offering limited local relief but insufficient to offset the regional crisis.
“In contrast, extreme deficits persist in the Mekong at minus 59.5 per cent, the Tibetan Plateau at minus 47.4 per cent, and the Salween at minus 41.8 per cent,” the Snow Update 2026 said.
“What we are seeing is a persistent trend where the seasonal snow reservoir is shrinking, year after year,” said Sher Muhammad, author of the HKH Snow Update 2026. “The 2026 numbers confirm a breaking point: ten out of twelve basins are below normal, and several have hit their lowest recorded persistence in two decades.”
Almost 240 million people depend on the glaciers and 10 major rivers, such as Indus, Ganga, and Brahmaputra, originating in the Himalayas. Another billion people living downstream of these rivers across eight countries, including India, too are dependent on the glacier-fed rivers.
In the Ganges basin, the snow persistence this year was 16.3 per cent above normal, making the number of below-normal and above-normal snow years equal over the past 24 years.
“This above-normal snow persistence may support improved early-season water availability in the basin this year. Besides the current year, the highest snow anomaly of 30.2 per cent above normal was observed in 2015,” it said.
In the Brahmaputra basin, snow persistence was at the highest level of 27.7 per cent above normal in 2019 vis-à-vis the lowest level of minus 27.9 per cent below normal recorded in 2025.
“The below-normal trend in snow persistence continues even in 2026, although the level of decline is less steep in the current year, recorded at 6.1 per cent below normal.
“This continued trend of negative snow anomaly has an adverse impact on hydropower generation and agriculture, especially in early summers, and emphasises the need for integrated water resource management and drought risk planning,” the report pointed out.
The Indus basin experienced a steep drop in snow persistence from a highest of 19.5 per cent in 2020 to 24.5 per cent below the normal level in 2024. It is also the lowest that the basin has faced in the past 24 years.
“The below-normal anomaly continues in 2026, too, recorded at the level of 18.1 per cent below normal. This decline is likely to exacerbate early summer water scarcity in a basin where nearly half of the runoff contributions come from meltwater. This threatens almost 300 million people and highlights the need for stronger water management strategies,” the report added.
Snowmelt contributes about one-fourth of the annual runoff on an average in the 12 basins, meaning reduced snow this year will directly impact water availability for drinking, irrigation, hydropower, and ecosystem.
“This situation is particularly concerning for water supply and flood management. Reduced snowmelt will lower spring runoff and intensify water scarcity in downstream areas, especially in the western river basins,” pointed out the report.
Farmers in the Indus, Helmand, and Amu Darya basins face irrigation shortfalls during early growing seasons. Hydropower operators in the Mekong, Yangtze – where the Three Gorges Dam operates – and Brahmaputra should anticipate below-normal generation in the early summer.
Compounding the crisis, consecutive low-snow years have prevented groundwater and soil moisture from replenishing, increasing vulnerability to future droughts. “Every dry spell will hit harder,” warned the report.
“Regional cooperation on these interconnected issues has now become urgent. We need to shift from emergency response to proactive, science-based governance,” pointed out the report.
